If anyone is still looking for a SLP-98

Funny. I looked for a good while and each time I found one, it would be gone by the time I tried to buy it. Maybe you remember that I settled on the Aesthetix Calypso Signature. Got it home, used it for a couple listening sessions. It did a nice job for listening to CD's. I'd never had tubes in line for CD listening before so that was kind of nice. I did not really get to appreciate it so much for vinyl as I was having problems with a weak tube in my Cary phono preamp as well as trouble with the turntable I was using. In the meantime, the Calypso started having a problem. LED's were dim and almost no sound. I found a loose RCA cap on the back, maybe all there was to it but I talked with TMR about it and they suggested to just send it back to them for repair and evaluation. It made me kind of nervous about it and I decided to just trade it for a Linn LP12 that they had. Waiting for that to arrive. Only took me 50 years to get one. I hope I like it.

At the same time, I found a Cary SLP 98P F1 in Jaguar red. It has several upgrades, including Lundahl phono input for LOMC, Hexfred recifiers, is direct coupled (supposed to help a lot) and has oil filled caps I don't know what all that means but I know that the upgrades are considered to be important. It also has a new compliment of tubes with only a few hours on them, not burned in yet. I may be looking to vintage tubes as these are all new types and I probably won't like them. 

@billpete what tubes did your 98P F1 come with?

Hey, before spending more on tubes, it’s worth opening the bottom, taking a photo of which oil filled caps are in it. Are they gold color Jensen or Jupiter, or something else. The sound changes notably with different coupling caps, or different 6SN7s, and different interconnects can impact the sound. Depending which way you want to go, softer/smoother, or more detailed and more open, we can help steer you on cap changes to fwiw. A local tech can swap caps pretty easy later if necessary.  

Once we know the tubes and caps, you can also try different 6SN7s up front which can go in either direction as well.

I believe I was told Jensen caps. The tubes are EH 6SN7, I think 2 are gold and two are not. AU's and AX's are JJ. Probably not what I want to hear. I have quite a lot of vintage AU's and AX's and variants that will be better than JJ's. I've never had or heard JJ's but what I read isn't so great. This is only the phono side I think so might not really affect me too much since I use the Cary PH301 phono pre. I just thought it was a fair option to have the P version, especially with the Lundahl MC upgrade. If the PH301 ever goes down or is off for repair, I still have a phono section that I might care to use. I have others in other preamps, they just don't do what I want. 

As to a local tech, probably nothing within less than 3 hours of where I live. My son does some of this but he is amateur at best. I have done a little too but this stuff makes me a bit nervous. We'll see what I find when I get the preamp. Thanks for all.

I don't know how good the EH tubes are. Never had or heard any of them either. I'm sure I'll be looking for vintage tubes at some point. 

@billpete , I remembered a thread where someone was sort of considering/looking for a SLP-98, but I couldn’t remember the thread or who the OP was, so when I got the preowned notification email from Cary Direct this morning, I figured I’d pass the word.

Anyway, it sure reads as if you have got yourself a nice one. Although it wouldn’t be a factor for me, that Jaguar Red is pretty. A couple of things I was not aware of until I did a look on Cary’s site was that it uses 12au7s and ax7s for the phono stage, and I didn’t know that it used solid state rectification until you mentioned the Hexfreds. Btw, I have read that the Hexfreds make a big difference.

As far as the JJs and the EHs go: I have heard mixed about both of them. On the JJs, probably more bad than good. But I do have a tube guru friend on another site who swears by the JJ 12ax7s. I owe him more than one favor, so I had some Mullard 12ax7s I took out of an old Bogen receiver and I offered to send them to him as I have nothing that uses them. He emailed me back, thanks, but for his money the JJ12ax7s were as good as anything out there. I’ll dig through my emails back & forth from him and see if I can find that one and I’ll paste that content to this thread.

As far as the EHs, my SLP-05 came with EH 6sn7s, and I actually decided to try JJs in the phase splitter sockets. I cannot honestly say that I can hear a big difference in either direction. Vintage 6sn7s in those sockets are on my list. As far as the two balanced input sockets, the tube guru who I referred to a paragraph or so ago gave me a plethora of pairs of vintage 6sn7s (he no longer has equipment that uses those tubes, but when he did I believe he may have been a tad OCD) and I have found that some of those vintage pairs for the two balanced inputs transform the sound of that preamp. So, as I typed, a vintage quad is on my list. If the phase splitters had the sonic effect that the balanced inputs have . . .that should be another "wow!" moment.

Anyway, good luck with that new to you preamp; I am sure you are going to enjoy it, and feel free to keep us updated.

Thanks for all.

Seems to me that Brent Jessee speaks well of the EH and JJ's but I may be mixing him up with another tube site that I go to. Most who sell something will have at least "something nice" to say. Hard to sell things if you say, "hey, these are crap but maybe you'll like them". :)

Seems to me that Brent Jessee speaks well of the EH and JJ's but I may be mixing him up with another tube site that I go to.

Hmmm . . . I think that you may be mixing him up with another site.

Tube depot maybe but I think Brent Jessee does sell some EH and JJ tubes. Any modern tubes I've ever had looked to be very poorly made. I haven't had a great deal of them but Mazda, some Chinese and Yugoslavian (EI?) tubes and none were what I'd call good. All that said, I have not had EH or JJ so I will be hearing them one of these days. Seems to me I read good things about Gold Lion and I think they are fairly new, or even still current, not sure.

So, having Hexfred rectifiers, does that make the SLP 98 a hybrid? 

So, having Hexfred rectifiers, does that make the SLP 98 a hybrid?

@billpete , I make no claims to be an electronics or tube guru, but I’d say that a piece of tube gear that  utilizes solid state rectification is NOT a hybrid. From what I have seen, there is an awful lot of tubed units using solid state rectification (perhaps the majority?) and I am just about sure that those are NOT considered hybrids. I had always thought of hybrids more in line with amps, and those were amps using input tubes but solid state output. But I may be mistaken--I often am.

A friend of mine sent me a Moscode preamp and it is called a hybrid. He sent it to me to see if it needed tubes as he has no way to test and it had stopped working for him. It had a bad mute switch that just needed cleaning. I was not overly impressed by it but I've heard worse. For whatever reason, it is called a hybrid preamp. Some people speak highly of them. Left me kinda "meh". 

Thanks for your explanation. You're well ahead of me on this stuff. I am an avid listener and I try when I can to understand some of the basics of electronics and that's about it. I have no intention of trying to build them. I may replace a part here and there but my skills in that area are very limited. When people start talking electronics to me, I feel like I'm back in kindergarten. I do pay attention though so don't give up on me. Thanks again,

A friend of mine sent me a Moscode preamp and it is called a hybrid.

Well, as I typed, I may have been mistaken about that part.

You’re well ahead of me on this stuff.

I wouldn’t say that at all, @billpete .

When people start talking electronics to me, I feel like I’m back in kindergarten.

Me too. I can solder and de-solder, but I am really bereft when it comes to understanding the  topology of the circuit that I am working on.

Yup, I just bought a desoldering rig in the last year. No idea what took me so long. Very handy tool. Knowing almost zero about all of these components is what makes me nervous. With no experts anywhere near where I live, I have to send things away to be worked on and I really don't know who to send to. There is a semi-retired guy in FL who sells "rebuilds" on ebay. I know one in TX but he is booked for 18 months at a time. I'm getting way too old to wait that long. I did send a VPI bearing to VAS. Still waiting for a verdict. He is likely to get some re-tip jobs from me as well. 

If it's a simple de-solder and solder in a new piece, I'll likely take a stab at it. Between my son and myself, we can take care of the simple stuff. I talk to the guys over at DIY audio too and they are helpful, just speak a different language than I do. EEese. 

@billpete I believe I was told Jensen caps. The tubes are EH 6SN7, I think 2 are gold and two are not. AU’s and AX’s are JJ. Probably not what I want to hear. I have quite a lot of vintage AU’s and AX’s and variants that will be better than JJ’s.

Most of us put the original EH 6SN7s back in their boxes and stored with the factory preamp box to be used for future resale of the preamp. My least favorite tubes compared to others in the 98. As for small 12Au.. tubes, it sounds like you already know what to do there. I keep and run an all-new reissue set of tubes, and another vintage set I roll in rarely.

To start, I’d recommend keeping the Jensen caps installed for a while, you might like then with th right tubes in the unit. And getting ready to acquire and try a great quad of 6SN7s paired with a few of your best 12A... small tubes first. If that preamp has been sitting a while, give it at least a week to settle back in.

Also, trying a good pair of pure copper interconnects, and silver over copper interconnects can bring out a different presentation in that preamp. Worth trying a few different pairs/types for source/input and output to your amp(s). Keep us posted how it goes in a few weeks.

decooney

Thanks. What you're saying is pretty much what I gather from all the study that I've put into this preamp. At least this one comes with the upgrades and is further upgraded than some with the Lundahl step up. I could be mistaken on the Jensen caps and may have read it on another or in talking to Cary. I can't find it in my notes on this one so not sure. I'll open it up when I get it to see what is inside. 

This one has been sitting on the shelf for the better part of 5 years. I am buying it from the 2nd owner who bought it to pair with a Cary tube amp 12 something or other. I pay little attention to amps so don't remember the model #s. His Cary amp started to act up and needed repair so he barely got to try the SLP 98. I think he said he only put a few hours on it and probably wasn't overly impressed since it had stock tubes that only had 10 hours on them. I remember that feeling with my PH301. I could tell that it was special but Chinese and Yugo tubes had to go. Virtually every vintage tube was better than either the Chinese, or Yugo EI's. 

@billpete ...2nd owner who bought it to pair with a Cary tube amp 12 something or other.

Probably either the Cary V12, 12i, 12R amp, and I owned one for many years along with a few colleagues. Without a good local tech or Cary agreeing to service the 87lb monster, this happens. Many paired the SLP-98 pre with it or still do.

Maybe you could just plug it in and let it play on/off for a week solid, and make sure all is okay and nothing shorts out. Let those EH tubes burn, some say they are "okay" with more time, yet I will say I tried mine for a while and did not enjoy them. 

For an entirely different thread, or you can search old threads - many of us have posts out there about our batches of vintage and/or new re-issue 6SN7s. PSVANE direct (mfg) just sent me some replacement CV-181TIIs I like quite a bit, and I still have a few quads of TJ Full Music 6SN7s I run in my SLP-98L now. Mix them too.

Sounds as good or better than many of my vintage ones. The TJFMs (now sold to PSVANE Co.) have lasted well last 2 years, and time will tell on the new PSVANEs. I helped a friend with his integrated amp and we recently installed the new Horizon series in his. A little more detailed than former versions. With these, I keep my vintage 6SN7s mothballed and stored away and break them out once a year fwiw.

Yes, V12. He said it was a heavy monster. 

Will post when I get the SLP, should be next week.

The SLP-98P F1 is a very nice little preamp.  The jaguar red is especially beautiful I always thought. My favorite color on the Cary equipment. 
Cary Audio only used the Jensen oil caps as an upgrade (early oils were Audio 1’s), otherwise it was polypropylene. Eventually moving into the Mondorf’s.  The Jensen oil caps are a bit more laid-back and tame compared to polypropylene’s, which are typically more detailed and airy.  It’s all going to depend on the rest of your system and your taste.  Also polypropylene caps last longer than oil. Oil caps last about 5 to 10 years and may start leaking or dry up.  The leaky issues are more on amps with higher voltages than on the preamps though.  
Hexfred’s I thought we’re great upgrades on these. Upgrading from the standard diodes to the hexfred’s you’ll notice more detail and faster bass. The SLP-98 has always had solid state rectification, which does not mean it’s a hybrid. Hybrid has to do with the actual analog circuit not the power supply.  
The SLP-98P F1 can still be taken a lot further in sound quality with some power supply upgrades and even better coupling caps.  Installing some large10uf polypropylene bypass caps on all the PS electrolytic caps makes a big improvement.  We always used Solan as they are a good size and fit well.  The F1 should have Kimber Kable in it but maybe not.  Upgrading to a good quality wire makes a big difference inside.  The only thing I didn’t like about the Kimber was it’s not shielded and consequently, picked up information from the other inputs wiring if a source was still on. Now days, I’d look at some good shielded OCC wire. 
As for tubes, I always thought JJ was crap. Sorry but just my opinion.  EH are Russian and tend to be a more on the hard/bittle bright side for my taste. Old 6SN7 Sylvania’s are fantastic for detail or RCA for more smooth body.  Also Tungsol, etc. 

There’s not a ton of room inside of the SLP 98P F1.  It’s pretty jammed in there already so there’s not a lot of room for huge upgrades.  Adding the Solen 10uf Polypropylene’s caps will help a lot. 4 in the preamp and a couple in the PS.  And the PS I used to always at a couple of higher quality .22uf propylenes to bypass the Solen’s.  Really makes the power supply cleaner and improves not only imaging and that blacker background but bass improves  

Somebody else mentioned they had an SLP 05. It’s super important to match the gain of the tubes to get correct channel balance.  I used to do this on the bench with a scope and meter but it can be done with just a meter and a signal generator or CD player with a 1K sign wave CD into the single-ended inputs.  There are trim pots inside the unit, which has to be opened up and turned upside down to get to the pots that are mounted on the pc board.  Those trim pots adjust the volume to the rear negative phase tubes.  First make sure the two positive phase tubes are putting out equal gain by measuring the output with the volume control turned all the way up.  Once they’re equal then you adjust the negative phase trim pot to match the volume of the positive phase tube that’s in the front tube socket. You do this for the left side and then the right side until you have all four phases of equal output voltage.  DONT TOUCH THESE TUBES NOW.  LEAVE THEM IN PLACE. Now you move on to the balanced inputs. if your DAC has balanced outputs it’s perfect.  You can play the 1K sign wave into the balanced inputs and swap tubes until you have equal output voltage on all four phases.  Yes there’s a bit to this.  And this is why most people send it in to have it done but you can’t do that every time you want to swap tubes around so hopefully this will help somebody.  When ordering tubes it’s important to ask for tubes that are matched for output/gain.  This will make everything much easier.  Especially for those two front line level positive phase tubes and the two balanced input tubes.  BUT every time you change the line stage tubes (not the balanced input tubes) the negative phase trim pots will always need to be adjusted to match the positive phase tubes, otherwise the negative phase may be louder than the positive phase or way too quiet and not canceling out noise correctly and the volume into your balanced amplifier won’t have the same channel balance.

Thanks guys. You are an absolute wealth of information. I look forward to having the SLP in my system and more discussion to follow. Many thanks.

@harpo75 ,  interesting read on adjusting the trim pots on the SLP-05.  That sounds like it would be a lot of work to roll tubes.  And I guess to perform the procedure the preamp would have to be setting on some type of open support box so that it could be upside down with the tubes installed  and the bottom could be off (as I do not have a tube cage for mine).  I suppose if I was going to do this, the best thing to do would be to buy a tube cage from Cary.

Anyway, as far as this goes

  It’s super important to match the gain of the tubes to get correct channel balance. 

forgive me for this question, but is the bottom line that the goal of this procedure is to get the output the same on  both the left and right sides?

If that is so, here is what I have found with mine:

First of all I am using the balanced inputs, and I have what is literally a plethora of pairs of vintage 6sn7s that I can roll in those sockets.

I have used a test CD with "315 Hz System Setup and Balance Tone" and a voltmeter to check the output of the amp on both the L and R side.  If the balance has not been equal I have found that swapping the phase buffer tubes from side to side has no effect on the readings I have gotten.

BUT, if I swap the balanced input tubes from side to side, I have found that the uneven AC voltage readings follow the (balanced input) tubes.  I've actually found certain pairs of tubes in the balanced input sockets that give me very nearly equal AC voltage readings on both sides.  So if I have nearly equal readings, there should be no need to do anything with the trim pots, correct?

Here is what I have been doing with pairs of balanced input tubes when I am getting unequal readings with my AC vm: 

first I have noted that when I totally defeat one channel and check with  my sound level meter and  that I do not get equal db readings from both side of my room.  Therefore, I put the strong tube on the weaker side of the room. 

Secondly, I have played around with using the L & R "input level" knobs to achieve balanced readings on the AC vm, and after that adjust to achieve equal db readings with the sound level meter. 

And I realize that using the "input level" knobs to tune the system is probably not optimal.  Currently I have a pair of tubes in the balanced input sockets with the strong tube on the weak side and I am actually getting almost equal db readings with my sound level meter with both "input level" knobs turned completely up.  As long as I am getting that is there any need to adjust the trim pots? 

@billpete , a few posts or so ago I referred to an email I sent to a benefactor who had blessed me with a literal plethora of vintage pairs of 6sn7s. I really wanted to do something nice for someone who had turned me on to so many tubes either at bargain basement prices or flat out gratis, so I offered to give him a bunch of Mullard 12ax7s I had removed from an old Bogen receiver, and he replied,

"I appreciate the offer of the 12AX7’s, but I’ve laid-in a lifetime supply of my favorite 12AX7. For my ears and money, there’s no better 12AX7 out there today than the frame-grid JJ E83CC. That’s a really good tube."

I am not trying to convince you of anything, good or bad; I am probably among the least audiophile members on this board, but I just figured I’d offer you another perspective. It may be worth noting that he does not use 12ax7s in a preamp, but in a Prima Luna Prologue Eight CDP.

As far as 6SN7s go, knowing his high opinion of the JJ 12ax7, I once queried him about JJ 6sn7s and he told me that he had no experience with their octal tubes, but he had heard some people say that they were not bad and that for the price, why not check them out. Therefore I did put a quad in the phase buffer sockets, and to begin with I thought I did like them better than the EHs, but now I don’t know if there was much difference at all and maybe it was just wishful thinking on my part.

I will quickly share a story about some 6sn7s I bought on ebay. Among those vintage pairs of 6sn7s my friend turned me on to were a pair of RCA black glass VT231s. For several nights I had been trying out different pairs and I thought that some were pleasant sounding and that some were nice sounding . . . but the night I put those RCA VT231s in it was a serious "wow!" night. I found the detail to be mesmerizing . . . with more detail came better imaging and with better imaging the sound stage became more tangible. So going down the road a bit, I was drinking wine one night while I was surfing ebay, and I came upon some guy in France who was selling a sextet of those black glass RCA VT231s. I was like I cannot let these get away! I can’t remember whether I paid him five or six hundred, but where running six of those tubes didn’t sound bad, it wasn’t like six sounded incredibly better than two (I had been running the EHs for the other four at the time). And then, they started going cold on me one at a time. What I learned from that is that I will never buy used tubes on ebay again.

And good to read that we now have an answer as to what a "hybrid preamp" is. As an aside, the preamp I upgraded from with the SLP-05 was a "modded by Dennis Had himself"  SLP-90. The SLP-90 and SLP-94 both used tube rectification . . . the two rectifier tubes were on the main preamp chassis (as opposed to in the power supply box) on those two preamps. The SLP-05 uses only one rectifier tube (it is a different type, a 5AR4) and on the ’05 they put it inside the power supply box.

Anyway, @billpete , let us know your impressions with that slp-98. I have a feeling you are going to like it.

immatthewj

Again, thanks so much for all the info. I will absolutely post after getting the SLP98. I'm guessing that a bunch of new EH tubes and JJ tubes are not going to be all that pleasing to me but who knows? It will take a good while to burn them in as well. They only have 10 hours or so on them and likely have only been in place each time the unit has sold. I'm #3.

Sorry for the delay in getting back to you on this immattewj. Too much going on in my life lately. Getting ready for a knee replacement soon also.
Just because you’ve pretty much matched the channels voltage wise, doesn’t necessarily mean you’re gonna get perfect dynamics since you have such a difference in gain of the first tubes on balanced input tubes. If there’s a big difference here on the input and then you’re trying to make up the gain afterward, in the line section it could change the sound in ways of the dynamics or image.
Also the important thing is to have equal output on all four phases of the signal. Meaning the left positive and negative phases and right positive and negative phases need to all be equal.
on your question as far as opening up the bottom, yes, that has to be done and they can be turned upside down on top of some foam or rubber. The tubes don’t get super hot so we never really had a problem with it, melting, some good packing foam. No cage is needed.
In a home environment you can simply do what you’re doing using a test signal in to the preamp and using a voltmeter to measure the AC output with the volume all the way up.
You should always start with the preamp set to a single ended input. Your DAC or CD players usually outputs about 2V into the preamp.
Now with signal into the RCA input you measure the RCA single ended output. Step 1: Now swap tubes 1 and 2 with other tubes until you have equal output at the R&L RCA outputs.
Step 2: Continue with the signal into the RCA single ended inputs. Now with your AC voltmeter measure the balanced outputs. Pin two of the XLR is the positive phase and pin three is the negative phase. If these are not equal the potentiometer inside needs to be adjusted until the rear tube (neg phase) matches the front tube.
Tube 1 is the left positive phase tube, tube 4 is the negative phase.
tube 2 is the right positive phase, tube 5 is the negative phase.

The potentiometer inside, adjusts tube 4 and the other one adjusts tube 5 gain. The potentials are aligned with the channels.
Once you have all four phases equal on the XLR output jacks using the single input then you’re ready to move onto the balance input tubes.
*Do not touch these four tubes now. Move on to the balanced input tubes.

Now switch the selector switch to a balanced input and plug your DAC into that input. While playing a test on measure all four phases of the output at the XLR jacks. All four phases should be equal again, if not swap tubes 3 & 6 with each other or with other tubes until you match the channels.

Tubes 7 and 8 are just for the headphones. If you are not using headphones, you can leave these two tubes out. That will actually provide less current draw on the regulators for the filament supply.

For people who have an SLP-05 and are only using it single ended, you’re missing out and you are only using tubes 1 and 2. Nothing else. But you do have to have four tubes in the preamp, them being 1, 2, 4 & 5. Tubes 3 & 6 can be left out if you’re only using RCA single ended in and single ended out. if you leave tubes 4 and 5 out, you will not get any filament supply to tubes 1 and 2 as it uses a 12V supply with tubes in series.

Hope this helps! Let me know if you have any other questions.

@harpo75 

Got the SLP98P F1 yesterday. Hooked up and tried it today. I have no sound and no LED's light up. The 6SN7's do not glow at all. They seem to not be getting power. The 12AX and 12AU tubes do glow even though not in use. I wired to AUX circuit so I can use my PH301 phono amp. I would try the SLP98 phono at some point just wasn't bought for that purpose. 

Anyway, the PS box seems to run quite warm. My PH301 PS box is nearly identical and does not run warm at all. I opened both cases, PS and preamp, took a couple pictures and put covers back on. Did not look odd at all to me and I touched nothing inside. If you have any ideas, I'd love to hear from you. If I can figure out how, I'll post photos. Thanks for any help you may have. Much appreciated.

@decooney 

Got the Cary SLP 98P F1. Beautiful to look at, like new. Only problem is, I have no power. Hoping to hear from Harpo since he seems to know these things inside and out. I took covers off of the preamp and PS, took a couple pictures and put covers back on. Everything looked fine to me but other than a broken or disconnected piece, I wouldn't know what to look for anyway. 

It has the gold Jensen caps, was fitted with Hexfreds and direct coupled. If I can ever figure out how to post pictures I will. 

@immatthewj 

Hope to be touching base with you one of these days to talk tubes. Have a problem from the get go. No power to the line stage side. No idea what is up. PS seems too warm. Don't know what to make of it. 3 tube preamps in a row with something wrong. I know they all worked before coming to me. My luck. 

@billpete do you think you'll just return it -or- possibly asking the seller to take it to a local tech to figure out where the power stops at the PS or tracing through inside the preamp with a volt meter etc - 

Was it flopping around in the box when you unpacked it?  Being careful to not arch across the caps, can you tell if anything came loose inside rattling itself apart during shipping?

@decooney 

Trying to figure that out now. I didn't notice anything but I'm not the one who should be looking. I can see if something broke or got disconnected but that's about it. I talked with the guy I bought it from and he's a bit baffled. I do not want to send it back. I want it to work. Will have to see what a few people have to say. Might be something very simple. I do not know. 

@decooney 

@harpo75 

@immatthewj 

OK, it's official. I'm an idiot. I had the umbilical on wrong. No idea how that's even possible but it was. All is well now, probably just took some hours off the PS caps making it too warm. Good grief. I'm a happy boy now. It even sounds good with croppy new tubes. 

Ahhhh yes.  The is a nub on the connector that fits into the notch on the chassis’s jacks.  Always have to make sure you get that in the groove. 
If it’s working you may have lucked out.  It was probably shorting the transformer and so got hot.  Lucky it didn’t fry it.  
About the only real failure I see on these is the bridge rectifier in the power supply.  Typically though the SLP-98’s just work for years.  

Nice easy find @billpete and this is good news, happy for you. Okay, let that baby bake in for a week with the supplied tubes and maybe turning it on/off a few times cycling the tubes hot cold a few times. Two of my own Cary amps and preamps had the Jensen Gold oilers and they are not too bad. I left mine in the 98 pre as-is, and chose not to use the same Mundorf EVO SGOs like I have in my amps though.  

It'll be interesting to get your thoughts after you and your ears settle in with it more.
Happy Listening for the weekend! :) 

@harpo75 

@harpo75 

Yup, I'm fully aware of the nub/keyway on umbilicals. When it dropped in to where I could tighten the nut, I assumed all was well but yet something didn't feel "quite right". I never thought it would go in far enough to tighten the nut if the nub wasn't lined up. My eyes in evening light, not so good. I am old and have AMD. These things always go by feel for me. Lesson learned. I do think I dodged a bullet in that it didn't fry itself. I am very pleasantly surprised in what I hear even from new stock tubes. Thanks very much for your help.

It’s OK billpete. It happens to the best of us. Even as a technician it happened a couple times to me. Among other things! I’m retired and a few years out from my tech days. First my back went, then my neck went-had a fusion, now my knee is gone. Sucks getting old! It’s a good thing your body doesn’t fall apart till your old, young people couldn’t handle this.

As a tech the worst thing that ever happened to me I think was being shocked by a CAD-805 amp that was wired wrong. An assembler wired the main B+ directly to a speaker post so that every time I grabbed hold of the chassis to turn it over and I grabbed the speaker post I got shocked by 1000 volts even with it off. It took a second time getting shocked, which turned my finger white and burnt a deep hole, to realize where I was being shocked from. Believe me 1000VDC will make your muscles spasm good. And that’s with the amp off and unplugged. Those caps hold a charge for a while.

@harpo75 

Thanks for that. I concur, getting old absolutely sucks and you're right, young people could not handle it. I've had multiple back injuries, including a fracture and multiple ruptured disks. Lots of hard and heavy work and now I'm paying for it. No surgeries yet, hope to keep it that way. No pills either. Eyes getting worse, might need cataract surgery one of these days. Ok, enough of that. I think this place is supposed to be about music. :)

Can't imagine how that felt. I hate electricity.....or at least the bite that it has. It's no wonder there are so many warnings on this stuff. I seem to draw static charges and get shocks when no one else does. I may be one of those negatively charged types. I guess I should be careful in lightning storms. I do know an auctioneer who has been struck twice. I joke that someone is trying to tell him something. 

Anyway, thanks for all. I will try to post some pics of the "innards". 

@billpete I seem to draw static charges and get shocks when no one else does. 

Your system likes you and is pulling you in to become part of the electrical and audio circuit now, LOL.  On that note, surely you are well aware, in any case, be sure not to touch a screwdriver or metal object on the screw heads or ingoing leads on any of those capacitors in the power circuit or signal path. Interesting about it having hexfreds in your preamp too.  Keep us posted on the listening notes every few days and whether you like it or not.  Others will follow this thread later too.  

@billpete , I am happy to read that you are up and running.  I've made mistakes similar to that before and it was always a relief to figure out it was just my own stupid owner/operator error and not a serious product defect or malfunction that was going to require a lot of shipping and waiting.

@harpo75 , thanks for all of that in your above post.  I am going to pate it to a word document and print it and keep it with my owner's manual.  Although after my first quick read, it does seem to make casual tube rolling prohibitive.  BTW, are you still in the tech service business?

I’ve been retired for 4 years now.  Worked there for almost 11 years.  I designed the ultimate upgrade for the 05 after tinkering at home for a year on my own.  Then for myself I hand wired a completely from scratch custom 2-chassis unit at home with a remote control resistor ladder volume control and input selector with display.  All teflon sockets, pure silver Kimber for hard wiring and silver solder, Mundorf’s top of the line EVO SilverGoldOil coupling caps, a completely from scratch larger power supply with a slightly higher voltage transformer, 10Hy choke, a few large electrolytic can caps and over 500uf’s of Polypropylene caps in the PS.  I installed a PS isolation circuit between the balanced input circuit PS and the other tubes that is a capacitance multiplier circuit.  
Did the last part this last year and was a wonderful improvement to the imaging. I have a hard time leaving well enough alone even now days.  
Then there’s my custom amps.  But that another story. 

A little history on the “F1” version of the SLP-98. That was originally asked for by Upscale Audio. They wanted an upgraded version of the SLP-98 with the HexFred diodes, the grayhill switch and I believe Jensen oil caps. The last few years I was there, we started doing extra things like added 10uf polypropylene capacitor’s across all the electrolytic power supply caps, higher quality coupling caps, etc. in addition to the F1. It really is a very nice preamp!

As I remember “SLP” stood for Sweet Little Preamp and “98” was the year it came out. 

@harpo75 

Yup, I've read about the Sweet Little Preamp and the 98 significance. Same with the 80. 90. 94 and the 05 I think. Apparently, Dennis Had used this "code" in a number of builds, at least preamps. Maybe he had some meaning behind all the numbers. Who knows?...........Well, you might I guess. The F1 seems to be a very nice upgrade from what I've read. Hexfred and direct coupling being more. Not sure what else is in there, several blue smaller caps, wixa or something like that? Definitely has the Jensen gold/yellow caps. Not sure what to look for as to grahill switch. Having the Lundahl step up for MC I guess is another fair upgrade. I have a photo of the guts but haven't figured how to post yet. It appears that we have to pick a host site for photos and then bring them here? Haven't done that in a good while but will try it if that's what we have to do. 

@harpo75 , I am going to hijack my own thread a little bit, but I guess since it is mine (the thread, that is) it is okay.

Anyway, a couple of generalized questions about the SLP-05, when the power supply is turned to 'ON', as I understand it (from the owners manual) all that is doing is putting it in a mode where turning the preamp knob to 'ON' will activate the power supply, but nothing else?  In other words, with just the power supply knob turned to 'ON', the only thing that is happening is that the blue LED light on the knob comes on, but if I am reading the manual correctly, nothing else?

And I am pretty sure, but I will ask anyway, that the meters on the power supply are indicating plate voltage and plate current of ONLY the rectifier tube?

Sorry, pretty simpleton questions, but I am a simpleton, and I just wanted to make sure that I was understanding this correctly.

You are right on both questions.
Yes, when the power switch is ON on the PS it is only applying power to the relay board inside the PS. This powers a small 12V transformer that powers a relay. The relay is then activated by the switch on the main Preamp when it is set to ON.
The switch on the preamp connects a ground wire back to the relay in the PS which turning on the power to the main transformer. That transformer provides the high voltage and the filament supply.
The reason for all this is to keep all AC voltages out of the actual Preamp chassis. The Preamp switch triggers the relay by connecting it to ground.
Am I explaining that well?

P.S.  The meters are connected to the DC voltage coming from the rectifier tube like you say.  They are not perfectly accurate but are a great reference point to keep an eye on.  Once warmed up they should always read pretty much the same.  Baring some AC voltage variations from the house wiring.  Sometimes people freak because the current is reading a little low.  You may also notice  then that the voltage is a little higher that day. 
Where the meters are useful is if you suddenly notice a higher current draw.  This would mean there is a short somewhere.  Start by changing the rectifier tube.  If a new tube doesn’t correct the high current draw then you either have a 6SN7 tube shorting or a bad PS capacitor.  If you pull out all the 6SN7 tubes and turn it on and it still drawing high current with a good rectifier tube then you know you have a shorted capacitor somewhere.  

In my setup I’ve found I like the old NOS Sylvania 6SN7 chrome top tubes except for the balanced input position tubes.  Because my DAC tends to be a bit lean for my taste I really like the Sylvania 6F8G tubes (which need to be used in an adapter).  These tubes sweeten things up nicely yet don’t loose much in the way of dynamics.

@immatthewj 

I didn't mean to hijack your thread but I guess I more or less did take it over. I should be more mindful in the future. Sorry. 

I didn't mean to hijack your thread but I guess I more or less did take it over. I should be more mindful in the future. Sorry. 

@billpete , that comment was not directed at you or anyone else!  If you took it that way, I sincerely apologize!  It was just kind of an offhand joke since I started the thread out as a heads up for anyone looking for a SLP-98 and then here I am asking Harpo SLP-05 questions.  Honestly, @billpete , threads evolve into other topics all the time here on A'gon, I have done it on many other threads by other people, and I honestly don't care what anybody types about on a thread that I have started.  Again, if you interpreted that as a snark I was directing at you, I aplogize because I did not intend it as a snark towards anyone, except maybe myself.  And after I post this reply, I am about to divert my thread some more!

Am I explaining that well?

@harpo75 , yes you are, and thanks for getting back to me on this! And from what you have typed, there would be no advantage to keeping the knob on the power supply turned to ’on’? As a matter of fact, if anything, it could be a disadvantage because the transformer could be a potential part to fail?

Where the meters are useful is if you suddenly notice a higher current draw. This would mean there is a short somewhere. Start by changing the rectifier tube. If a new tube doesn’t correct the high current draw then you either have a 6SN7 tube shorting or a bad PS capacitor. If you pull out all the 6SN7 tubes and turn it on and it still drawing high current with a good rectifier tube then you know you have a shorted capacitor somewhere.

And thanks for that also, @harpo75 , you are a wealth of information for me on this preamp and I appreciate it. I think Cary could have provided this in the owner’s manual, but anyway, thanks again.

except for the balanced input position tubes. Because my DAC tends to be a bit lean for my taste I really like the Sylvania 6F8G tubes (which need to be used in an adapter).

Via the generosity of a kind benefactor, I actually now own several pairs of 6F8Gs and I am currently running a pair of National Unions in the balanced input slots, and I love them. The same generous individual also turned me on to numerous pairs of 6SN7s and VT231s, and my favorite pair of 6SN7s in the balanced input slots were a pair of ’52 Bad Boys. My friend called the Bad Boys "the Iron Fists" and the National Unions "The Velvet Gloves."

Anyway, with that trivia aside, can I trouble you with another question? But this one is about the Hexfred rectifier diode(s) on the V-12. About five years ago I had a coupling cap go out and on start-up the bias would instantly run away high on that side, and to make a long story short, the way I troubleshot it was that I took the bottom of the amp off and took comparison (left versus right) readings on everything I could find . . . and of course, one of the coupling caps (they were the gold colored Jensens) read way off, so I replaced all of them with Mundorfs. But this is a rectifier diode question, and to the best of my recollection (and my recollection may be flawed) I only found one diode under there. How many rectifier diodes are there on the V-12, and if I did the Hexfred upgrade (which I would like to do) is this a one for one swap?

Hey, thanks a lot for your help on these Cary questions, @harpo75 , I truly appreciate it!

Oops: double post for some reason.  Removed on edit.

@immatthewj 

I took it as the offhand joke but considered that I had sort of taken over the thread as well. All good, my apology to your apology to.................and so on. :)

@billpete , please rest assured that you did not take over the thread, and even if you had, it wouldn't have been a problem as it was kind of an open ended thread (open to anyone who was looking for a SLP-98).  Anyway, on A'gon threads often evolve into threads within threads and can be quite helpful and informative in that manner, and that is one of the tings I like about A'gon threads.  Anyway, I didn't intend to insult you or anyone else, so if it's all good, I'm happy.

@immatthewj 

It has been very informative. I'm happy too. 

Greetings immatthewj.  If you’re only seeing one diode rectifier, it’s probably the negative bias supply rectifier.  I do put HexFreds in the bias supplies of my personal amplifiers.  Had a hard time telling if it really helped there though, but figured it couldn’t hurt.  Because like the old saying goes, everything matters.  I do know adding more filtering to the bias supply definitely makes a cleaner sound quality.

The V12 amps should have four strings of three diodes totaling 12 diodes for the high voltage supply.  There is such a high current draw (large caps) that there are three in series for what should be one diode in order to keep them from blowing out from the turn on surge.  I remember doing a few amplifiers (not just V12’s) with HexFred’s, but that gets very expensive as you’re installing 12 so most people didn’t want to do it. In fact, I think on a pair of CAD-805 amps we installed 16, four sets of 4 just to make sure the amp never came back with an issue.  Now days, there are higher current HexFred’s available that can be used but you still want a couple in series.  I’ve had to buy some of these because I use so many large value capacitors in my mono-block PS’s.  My amps have two amp chassis’s and two power supply chassis’s. 
It’s not that you’re drawing a lot of current tube wise. It’s the turn-on surge to charge the capacitors.  The more capacitors, the bigger, the surge, and the more the rectifiers see a short initially at turn on.  

It’s not that you’re drawing a lot of current tube wise. It’s the turn-on surge to charge the capacitors.  The more capacitors, the bigger, the surge, and the more the rectifiers see a short initially at turn on.  

Thanks, @harpo75 , and that would explain why that when I had a Cary DIY  external power bank (four more large caps) hooked up I was frequently blowing fuses on start up.

The V12 amps should have four strings of three diodes totaling 12 diodes for the high voltage supply.

And thanks for that; now I will know what to look for.  If I can find the part in question, I can usually change it.