Cary Audio SLP-05 First Impression

@xcool Now I know what all that fuss and craze of tube pre/power amps are about. I guess you simply have to experience it to appreciate it. ...

 

Yes, congratulations in order, after you get your replacement back. Darn shippers, it happens, even when double-boxed by Cary. Argh, keep your fingers crossed. Fwiw, the upgrades DO make a real difference. Brings it up another level. Any informed Cary owner will share this.

It’s too bad you cannot splurge and do the upgrades now, before shipping it out again. Saves you added shipping damage-risk again later. Best of luck.

@xcool… congratulation! It is really difficult to describe until you hear it. But the satisfaction of hearing really great sounding music is amazing. I am very gratified in your experience.

 

I am currently vacationing, listening to my amazing portable (solid state) headphone system. I can say nothing but wonderful things about the sound. Yes, it is natural, detailed, etc… (A&K SP1000 + Focal Utopia). If I hadn’t heard a really good tube system like I have at home, I would not believe it could get better. But it is. 

congrats xcool!  love my slp05, turned a year old this january. 

holographic is the word for sure.  

do try tube rectifier and 6sn7 tube rolling down the road.

mine blew 2 meter led bulbs in 6 months, took a pic of the issue and cary sent me the replacements, not to difficult to diy if you can use a soldering iron. 

Nice write up! Are you running the Cary with the JC5 and does the JC2/JC5 combo have the punch your hoping the Cary will have once settled in?

Hi @jdub39, the answers to your 2 questions are yes and yes.  

To add a little more color to the 2nd answer, the Cary does seem to go a little deeper in bass, whereas the JC2 seems a little more punchy in some areas such as the drums.

Cheers!

@xcool Thanks for that as I have a JC2 on order for my JC5 but the thought of a tube based preamp has been grabbing my attention lately ,your comments and others on the Cary slpo5 does give one a clear path to work my way up to.

Thanks again !

Hey @jdub39, congratulations!  I think you'll be happy with the JC2/JC5 combo.   I recently upgraded the balanced cable between the 2 units, and it made a huge difference.  Check out this thread if you are interested.

I went for the Cary to satisfy my curiosity for tube preamps, and it turned out to be a pleasant surprise.   Have I not done that, I can see myself living happily with the JC2/JC5 combo.   They sound beautiful together.  I'm not planning to sell my JC2.  I like to keep it around so I have some varieties.

Good luck!

Congratulations and a fine piece.  It is impossible to overstate the importance of a quality preamp in a system.  Makes all the difference. 

Had that pre for many years.  Excellent pre.  Sold it for an ARC.

mirrors what most people say when they hear a good tube preamp for the first time.

hard to go back..

outstandingly nice sounding piece that cary was/is, tubey goodness but sufficiently transparent, not euphonically over the line like many cary units can be

sure takes up a lotta real estate though

I enjoyed your write up.

I picked up a "preowned" SLP 05 from Cary 7 or 8 months ago.

It was an upgrade from my ancient SLP 90.

I am finally getting around to shopping for different tubes.

Oh, and color me ignorant, or out of touch, but what is the jc2/jc5 thing all about?

@xcool Congrats on purchase of new toy. Cary slp 05 is a great unit and you will be happy for many years. I have slp 03 and I can only imagine how much better slp 05 would be. Only reason I am sticking with slp 03 is the remote control functions and NOS tubes collection I own including 12AU7s.

I just don't have the appetite to roll tubes in the slp 05. There are 8 x 6SN7 tubes in this unit. 6SN7 is a great sounding tube. I have a NOS collection of 6922 and 7308 but I don't think those can substitute for 6SN7. That circuit is optimal for 6SN7. I have heard many great things about this and do enjoy the new toy.

Congrats on the new preamplifier.  The SLP 05 is a winner.  Cary discontinued the power supply feet inserts for two reasons: no one was stacking the units, and a flat panel is cheaper to produce.  Cary has been shipping the SLP05 with a full feature remote for years, but since the Cary only adjust for volume and mute, I prefer a 3 button remote.  
 

I hope you run the pre in balanced mode, because that is where it shines. 

Thanks for all the comments.

@immatthewj, the JC2/JC5 are the pre/power amp combo that I’ve been using before replacing the JC2 with my new Cary. It was simply mentioned for comparison purpose.

@pwerahera, I am still very green on vacuum tubes. I guess I will tinker with it at some point in the future. Expect me to post some questions on this topic 😀

@testpilot, I agree with you on the 3 button remote. I’m already using a logitech harmony remote, and I don’t need another big remote.

There had been very few changes that I made to my system that produced such a dramatic difference. This Cary preamp is probably on top of that list.

The SLP-05 has been out for quite some time. I wonder if Cary is going to come out with a new preamp anytime soon.  I’ll be really angry if they do that in the next few months. 😀

"The SLP-05 has been out for quite some time. I wonder if Cary is going to come out with a new preamp anytime soon.  I’ll be really angry if they do that in the next few months. 😀"

I am usually wrong when I make predictions on this kind of thing, but I think that this may become the Cary 805 equivalent except it's a  pre-amp.

 

Yup, Cary products definitely have that 'wow!' factor Mr. Xcool.

How's the Cary doing?  Still living the tube dream?

I’ll be really angry if they do that in the next few months.

your preamp will still sound exactly the same

Hey @jdub39, I did get my replacement unit last week, and it’s still burning in. I took @decooney’s advice and decided to add the ’ultimate upgrade’ before they shipped the replacement. Knowing my own shopping habits, I know for sure I will get that itch to upgrade down the road, I figured I might as well save myself some hassles and shipping cost and get this done now.

I was going to post an update after I let it completes its burn in, which is 100 hours as recommended by Cary. Since you ask, I’ll just give you guys my initial impression.

So far, I have to say I am a little underwhelmed by this ultimate upgrade. I’m not getting the same ’wow’ factor as I did with my first unit, and I am trying to ask myself why.

Also just to remind you guys that I only had in my possession of the first unit for about 4 days, and it wasn’t even completely burned in. Here’s my impression so far:

The top end seems to be more smooth and I’m hearing no graininess at all. The first unit did have a slight graininess occasionally, which didn’t really bother me that much. However, I now notice the top end stands out more. I won’t say it is harshness. It just seems the top end is a little more accentuated, which is not what I prefer. I think it might have to do with the change in the bass response, which I’ll describe in the next paragraph.

The bass seems tighter, but at the same time it doesn’t seem to go as deep as the first unit. I wonder if it’s because a tighter sounding bass means the duration of the sound is shorter, so it doesn’t stick around as long to give you the sensation of depth. I’m just thinking out loud. I’m not an audio engineer. So far, I found the bass a little less prominent. Although it is tighter, I still wish that it is a little more punchy.

The holographic 3D soundstage that really made a huge impact when I heard it the first time in the first unit seems a little less prominent also. I wonder if it’s because my expectation is higher now.

So I’m going crazy now trying to figure out if the ultimate upgrade had changed the overall sound profile in a way that it no longer matches my hearing preference, or have I set my expectation up so high that it did not live up to it. Maybe it is a little bit of both?

I think one key factor might play a critical role to make this ultimate upgrade a different experience is that I was comparing the first unit with my existing JC2 preamp, and now I’m comparing the ultimate upgrade to the previous unit. I now wish I had kept the 2nd unit unchanged, and wait a little longer to upgrade. I wonder if that scenario will produce a different outcome.

For those who had done the upgrade, please chime in and tell me that it is all in my head. Anyway, I’m still hoping that the sound will continue to improve until it finishes burning in and possibly beyond that. I’m asking myself to be a little patient here. Or maybe my hearing will eventually burn in and adapt to this new sound 😀

Hang in there. Be patient. Frequently better parts take longer to break in. Break in will normally relax the sound (becoming more natural… less treble forward)… tends to get quieter and bass is reinforced. The soundstage opens up over time as well. . . On my equipment the first 150 hours are not good by the standards later achieved… then the sound can vary wildly good / bad, back and forth. It then it settles down and improves slowly over the next 400 hour. After that, while even more slowly it improves over the next 400 hours. So, 1,000 hours. But it is OK to draw conclusions after 600. I have been experiencing break in for 40 years… and I still get suckered into drawing conclusions too soon… doubting… then pleasant happiness. The upgrade was a great idea… we have similar personalities. Remember you will be listening for years.

I’ll be honest, I have a stock SLP 05 and was all set to pull the trigger on the ultimate upgrade until my friend who has an Ultimate 05 brought his over for a direct comparison.  After a couple of days of comparison, both of us concluded that we could not hear a difference between the two units.  I was a bit disappointed, but not as disappointed as my friend.  In the end, it’s an awesome preamp and is very responsive to tube rolling. 

@ghdprentice,  thanks for sharing your experience on break in.   I'm definitely trying to give it some time.   Will try to report back if my impression changes after it settles a bit.

@testpilot, interesting experience here.  It does help calm my nerve a little.   Last thing I want is to have the upgrade worsening the sound.  I agree this is still an awesome preamp, and it's still a keeper.

@xcool a few questions for ya, if known. Agree with others, give it a lot more time.

1) what 6SN7 tubes came with it (EH?)

2) and, the 10 Mundorf caps were installed, correct?

3) How many hours do you have on the SLP-05 now before/after upgrades?

i.e. some years ago Cary use to run them for 2-3 days before sending them out. Not sure if they do that any more. Caps, transformers, tubes all settle in. I used to see people pulling the generic stock EH tubes in the 05 and using Popes instead, fwiw. Wondering what they sent ya.

Having used those same caps in three different upgrades (preamps and amps), let me share right up front the break-in and cap forming cycle can be "aggravating" to say the least, on those. Prepare for what we call "the rollercoaster ride" on those Mundorfs. I was warned too before my first try. It’s true. I emailed the Mundorf factory and they confirmed this for me while I was getting to be very impatient. Sounded bad new. Seems like it took forever. Finally got there. YES, the sound is going to change at 100 & 200hrs, some say up to ~300hrs. I heard changes even at 300hrs. No joke. I use the same caps in my (other brand) current monos. Mine sound different now, much more engaging, nice tone, texture, smoothness and more after the 200 and 300hr mark. Patience will pay off.  Your experience may vary. I had to look again at the upgrade itself, link.

 

Yes more time will be needed as others have said , usually bass shows up 3/4 to just about the end of burn in and highs and depth during the final stages.

 

hang in there and keep us posted!

Hey @decooney, 

1) Yes, it came with the same EH tubes as the stock unit.

2) I haven't opened the chassis to check the capacitors.   I know nothing about capacitors so I wouldn't know what to look for anyway, but I'm pretty sure they did install the upgraded caps.  Well, I hope anyway.  The shipping box does say 'Ultimate Edition' on it, and the packing slip listed the ultimate upgrade as well.  So that gave me the confidence that the upgrade was indeed installed.

3) Before the upgrade, and I mean my original unit, I had probably only run it for less than 40 hours before shipping back.  My current unit with the upgrade has about 50 hours so far.

I'm not aware that Cary has done any burn in on the unit before shipping it.

Thanks for sharing your experience with the Mundorfs,  that really helps keeping my hopes up that the sound will continue to improve.   I will definitely try to be patience and let it play out.  Time for some meditation 😀

@xcool if you have not done so, take a look at that link above, it describes the upgrade and components.  The Mundorfs are obvious if you decide to lift the hood.

6SN7: after burn-in I never quite adjusted to the stock EH 6SN7 tubes in my own Cary preamp, fwiw.  Mine are back in their original boxes for safe keeping.  

After the 200hr point, if you still feel its not the sound you want, it might be worth it to start exploring SLP-05 owners threads for other 6SN7 options. 

 

@xcool 

do hang in there, lots of burn in required!

the ultimate upgrades do seem to be subtle but some tube and rectifier changes can be dramatic upgades.  

for tube rolling tubes 1,2,4 and 5 affect non balanced inputs, just get two matched pairs of the same tube with the pairs plugging into 1,4 and 2, 5.  

if you use balanced inputs ( highly recommended) then you need another matched pair for slots 3, 6.  

tubes 7 and 8 are for the headphone amp. 

i use 3 matched pairs of sylvania 6SN7 GTA from the 50s and the sound blows away the EH stock tubes.  you can barely listen to them after experiencing the sylvanias.  

also do upgrade the 5ar4 / gz34 rectifier to a nos mullard f32.  you can find brands made by mullard for reasonable cost. 

again, another dramatic upgrade, especially in transparency and dynamics.  

Hey @decooney, thanks for the suggestions. I did read the Ultimate Upgrade description on the Cary’s website.

I’ll keep your EH 6SN7 suggestion in mind. I’m sure I’ll get that itch one day to try out some tube rolling, but I know very little about it. May I ask you what tubes are you currently using?

FWIW, my SLP-05 seemed to start sounding better last night. I noticed a little bit more warmth was coming out.

One thing I failed to mention in my ’initial impression’ post yesterday, was when I first turned on the upgraded SLP-05 and listened for the first time, my initial impression was "This doesn’t sound like tube to me, it sounds more like solid state". Note: I’m not an expert in tube sound, but do have a little bit of expectation of what tube should sound like.

Hey, maybe my state of mind has changed after all the reassuring posts from you guys. Who knows. 😀

Thanks.

Thanks @avanti1960 for your tube recommendations.   I'll definitely keep that in mind.   There seems to be so many options, and my head is spinning already.  😀

@xcool "... I’m sure I’ll get that itch one day to try out some tube rolling, but I know very little about it. May I ask you what tubes are you currently using?"

Yep, with your fairly new preamp and burn-in going on, maybe save the "new tubes" idea for a next-chapter. Those stock EH tubes will get you through preamp burn-in cycle to start. The tubes I’m using (now) are not vintage NOS any more. I keep those hoarded away. Finding matched pairs and matched quads is difficult, costly.

There are various, and availability changes by tube seller and the best recommendation is to call a reputable tube seller who offers a guarantee.

For NOS, was previously using a tightly matched quad of Sylvania Black Plates, mid 60s, and past few years using new production TJ Full Music 6SN7s, and awaiting some of the latest PSVANE CV181-TIIs, soon. I missed out on the good Shuguang’s a few years back. Note, again, a good tube reseller (specialist) is where I’d start since you are new to this, when u are ready. Brent Jesse, Andy at Vintage tubes, Jim McShane are a few to note for vintage stuff. I’ve given up on vintage or NOS 6SN7s, rare, few matched pairs/quads out there, and way too costly. New production here forward. Best of luck.

 

Great.  Thanks for the info!

these will get you started... good price. good seller.

 

 

Great.  Thanks.  Lots of choices out there indeed!   I'm sure I will have a ton of questions for you guys when I'm ready to explore this tube rolling pastime. 

Hi everyone,  I thought I would give you folks another update on my new Cary SLP-5 with Ultimate Upgrade.

I’ve been playing it for a good 8 to 12 hours a day for the last 3 weeks.  I now have almost 200 hours of burn in on the unit.   I noticed a slight improvement at around 60 hours.  I started to hear a bit more warmth, and the top end had quiet down a bit.   Still hearing that nice tight bass.   The 3D soundstage that I most enjoyed when I got my first unit doesn’t seem to stand out as much now.  I don’t know why, maybe the initial ‘wow’ factor is no longer a nice surprise because my expectation had changed, or the Ultimate Upgrade has compromised some of the 3D imaging sound.   I hope it’s more of the former.   Overall, my impression of the Ultimate Upgrade as compared to the stock unit is this:  “Refined”.   The top end is more smooth, and the bottom end is more tight.  

Anyway, here comes the bad news.  When I turned on my system to start listening to my music last Thursday morning.   No sound was coming out from my speakers.   So I checked the SLP-05, I noticed the readings of the 2 blue meters on the power unit were way off from the normal values.  The user manual suggested that the readings should be around 210 VDC and 60 mA, which is what I’ve been seeing while the SLP-05 was working.   Now I’m seeing the voltage is pegged to the max at 300 VDC and the current is down to 30 mA. It is definitely not within the normal range suggested by Cary.   I also noticed the filaments on the 6 tubes on the left side of the unit were not lighting up.  Only the 2 tubes on the right side for the headphones were lit.

So I spent a good couple of days exchanging email with Cary support.  Everything that he asked me to try did not fix the problem.  So I contacted MusicDirect, which is where I bought the unit from, hoping they will be able to let me get a replacement again.   They replied saying that I have to work this out with Cary because technically this is a customized unit because of the ‘Ultimate Upgrade’, and they are not willing to be the broker to address this issue.   But they are nice enough to offer me a refund if I decide not to keep it, and made it clear this is an exception because it is a custom order.

Now I’m stuck in a dilemma of whether sending the unit to Cary for warranty repair, or sending it back to MusicDirect for a refund.  In either case, I will have to cover the shipping cost, which is not a big deal.   I hate to have to send this back to MusicDirect,  but I also don’t want to be stuck with a potential lemon.

I do like the sound of this unit, but I now have real concern with the reliability and quality control of Cary’s products.  I’m hoping this is just a one off anomaly.   So question for you Cary product owners out there:  have you run into quality issues with Cary’s products, or has it always been mostly trouble free?   and for everyone else, feel free to chime in and express your opinions.

P.S.  Remember I sent my first unit back for a replacement because the blue power LED light was missing?   According to Cary support, after they received the unit and they powered it up, the blue light was on.   They even sent me a picture showing me that the light was on.   This is indeed very strange, because when the unit was in my possession, the LED light was clearly missing, and never lit up.   I even sent a picture to Cary and they immediately thought it was dislodged because of rough handling by Fedex.   I wondered if the trip back to Cary had knocked the LED back in place.  Again, it raised my concern of Cary’s quality control.

Thanks for reading.

Wow, Xcool, as a relatively new SLP05 owner, that was a bummer to read.

My experience in the past with Cary Audio (SLA70, SLP90, power bank, V12) has been extremely positive. That stuff I listed was/is extremely reliable & when I did have questions, their telephone tech service was great. Their customer service, back then, was a big part of what kept me a customer.

About a year or so ago, my 20 year old V12 finally had a signal cap shoot craps and I wasn’t super thrilled with the tech support. I sent an email that wasn’t responded to, so I sent a couple of more, and what I got back was an email telling me to send them the unit & what their shop rates were. On a different audio forum than this one, an extremely kind and helpful & patient member exchanged about one thousand emails with me & I troubleshot & changed all 4 caps myself.

After that I had decided to swear Cary Audio Design off, but I heard so much good about the SLP05 with Ultimate Upgrade, that when a preowned one came up on their site I pulled the trigger &, like you, ordered the upgrade.

I understand your dilemma. I think if it was me, and MD was willing to refund me the price of the pre AND the upgrade, I’d reluctantly go that route.

I’ll be watching to see how this works out for you.

. . . I just looked at a note I made re my own, and I am usually reading 230 to 240 VDC and 55 to 60 Ma.

I am also curious: in the email exchange, what was the troubleshooting advice that Cary Audio gave you?

Here are the things that I was told to try:

- unplug all the source connectors, and power up the unit and see if the meter readings go back to normal. 

- check the fuses on the power unit. 

- make sure the unit is not on mute. 

- he did notice from the pictures i sent that my tubes were not inserted all the way in. He was correct.  They really weren’t pushed all the way in because i was afraid if i use too much force, i might break the tubes.  I ended up trying to push them down with a little more force and they all went further in and were seated properly.  Somehow  I was able to play it while the tubes were not completely inserted for a good 3 weeks.  Anyway, this didn’t solve the problem either. 

- Finally I was told to switch my sources to different connectors.  I had a balanced source and a unbalanced source at XLR2 and Aux1.  So I changed them to XLR1 and Aux2.  That didn’t work, but I found some other problem.  After i switched the connections,  I turned the unit on at XLR1, and no sound was coming out.   I then turned the source dial towards Aux2.   It skipped over XLR2 and Aux1.  When the dial landed on Aux2, all the LED lights went off, as if I have powered off the unit, but the power unit remained on.  I then switched the dial back to Aux1, the power LED came back on, and after a minute or so, the ready light came on, much like the normal power on routine.  It was pretty messed up.  I made a youtube video and sent it to Cary, but haven’t heard back since.  Here’s the video:

 

https://www.youtube.com/watch?v=GpWUXSan4Ig

 

 

 

Yes, the tubes fit tightly in those sockets. Personally, I would prefer to grip the tube by the base when I inserted it or removed it, but that was one of the first things I noted about this pre that I thought was flawed about the design--the fact that the tube sockets are recessed about 2" below the top of the pre, & unless you have tubes with higher than usual bases, you can’t do that. I was a bit worried about breaking something on the board by pushing to hard, myself.

As far as the plate voltage & plate current, I am definitely not an electrician or electronically minded, but I was thinking that those were indications of what was going through the tubes (ie "plate"), but  Cary didn’t suggest anything about the tubes.  (I thought it was indicating the bias of the preamp tubes.)

I have to find my computer headphones in order to hear anything that I am watching on my computer, so I will give that a go later on. With everything that is going on, I am kind of thinking that I would be inclined to take the refund from MD, but, will you have to eat the cost of the upgrade?

 

Hey @immatthewj,  I assume MD will give me the full refund, but I didn't ask explicitly.   

I'm pretty disappointed with this issue.  How unlucky can it be to have 2 defective units in a row, even though the first one was very minor.

@xcool

Really sorry to hear your experience… it must be incredibly disappointing.

I am really lucky, I have a great dealer whom I have worked with for twenty years. If I have a concern of some kind, he comes over and adjusts things. I had a weak meter on my amp… he gave me a set of better monoblocks and let me use (to compare) for an extra six weeks because I was enjoying it. If something ever failed… I have no doubt he would be over that day (or the next) with a loaner of better quality allowing me to have fun with it while he fixed whatever it was.

 

Also, he knew I would enjoy it… so he dropped off a set of $17K Nordost interconnects for a couple weeks. I really enjoyed them… although I was really starting to like them and had to take them out of my system because I was starting to like them too much.

xcool,

definitely get the power supply chassis out from under that shelf, it has a tube rectifier and gets fairly warm.  mine got very warm so i pulled it out and just put it on the top shelf under the preamp chassis in stacked arrangement.  much much cooler now.  

sorry for your units trouble, bummer.  

i had an issue under warranty where it would not power up the tubes.  the easily found and replaced the bad component.  

when mine was in for the repair i replaced it with a basic solid state preamp.  when my cary came back i could not believe how amazing it sounded in comparison to the solid state preamp.  it has been working perfectly for over a year now and i love the sound so much i will just get it fixed if it ever has another problem but i do believe strongly the power supply chassis needs good ventilation.  

 

Hey @ghdprentice, i would be afraid to listen to a pair of $17k IC also.  My system is definitely not worthy for that. 😀

@avanti1960, I agree with you about ventilation for the power unit.  It does get very warm.  My cabinet is actually open on the back, and I installed 2 AC Infinity cabinet fans on the back of the power unit to keep it cool.  I’ve been checking how hot does the power unit get.   It actually is not too bad.  It feels warm but definitely not hot to the touch.   Hopefully this is not the root cause of my issue.  

It’s interesting that you brought up listening to your SS preamp.  That’s what i’ve been doing the last few days also.  In my case it’s the Parasound JC2.  I realized that  it sounds pretty good.  It’s more laid back than the Cary, but it’s very easy and comfortable to listen to.   Cary is definitely more detailed and forward, and can really draw you to the music.  They both have their own strengths, and it comes down to personal preference, and what you’re in the mood for.  

The way I would contrast the 2 preamps is that listening to the Cary feels like you are sitting at the fifth row from the stage, whereas the JC2 feels like you are sitting at the 15th row.  

@avanti1960 that is a good dealer!

@xcool I am going to go out on a limb & say that I don't think being overheated is the cause of your problems; older model SLP05s (such as the one I bought) were actually designed by Cary with indentations in the top pf the power supply for the preamp section to sit on.  That typed, I have mine on a separate shelf, but still, that is the way Cary originally built them.

@xcool Sorry to hear about the troubles and  hope you get a resolution you can live with or just get your money back and move on. I had a change of plans and ended up getting an Musical Fidelity M8s preamp to go with my JC5 and as of today at just over 200hrs of play time I've decided I'm going to stick with it instead  getting the JC2. Its a fantastic transparent pre with beautiful coherent top to bottom sound along with great tone and startling dynamics.

Again keep us  updated on the saga!

Hey @jdub39, congrats on your Musical Fidelity preamp. I’m glad that you like the sound. That’s always the most important thing, no matter what other people think.

I’ve never listened to the Musical Fidelity, but the preamp sure looks good. I’m a sucker for good looks. Everything I own has to pass that ’good look’ test. 😀

I’m still deciding what to do about my Cary preamp, but I’m leaning towards sending it to Cary for warranty repair. I do love the sound, otherwise I would have just returned it and get the refund. Also, both MusicDirect and Cary Audio are great companies to work with. I have no interest in screwing them over.

BTW. the latest email exchange I have with Cary about possible root cause is that I did not insert my tubes properly and it might have cause some issue with the circuitry. I’m not an electrical engineer (but I’m a software engineer 😉), but I guess it sounds probable to me. I wonder why I was able to run it for a good 3 weeks without any issue, and it literally just stopped working overnight. For those who are knowledgeable with tube amp circuitry, please feel free to chime in. Would like to hear your opinions.

@xcool Glad to hear your sticking it out with the Cary as it could also be the reason for the sound change? That alone would have me curious to hear it working as should, as nothing is perfect and good support goes miles and miles on anything we purchase and sounds like your in good hands. Thanks on the MF, I scored major WAF points between the M8 preamp and Marantz 30n sacd I got to go along with the upgrades both in silver and as the wife helped me unpacked them  and when removing the beauty bag she  was stunned at the looks and understood the $$$ spent for the first time!

Yeah it does have to look good for me as well or it's a no go!

@xcool I respect you for not wanting to screw over either MD or Cary Audio, but returning a product that you paid a lot of $ for, and one that is not operating at all or operating as advertised, is not what I would define as screwing someone.

As far as the tubes not being completely pushed into their respective sockets . . . I can see how that might degrade the signal path, but I am not getting how it would cause damage that would cause the unit to completely cease to function . . . but as I typed earlier, I am not an electrician. (Maybe that caused some fluctuations in the current between the socket & the pins of the tubes that caused a cap or a resistor or a diode to fail?)  Good luck with this whatever you decide to do. The SLP05 certainly is a good looking unit, and so far, I am finding mine a unit that sounds delicious.

how do you compare the cary pre to the herron you said you have.....

@immatthewj,  I understand your rationale on returning the unit that is not working the way it should.  I feel bad because MD had already replaced my unit once.  They actually were going to repair my first unit, but I asked for a replacement, and they were happy to accommodate me on that.  Since this is the 2nd unit, and a custom order, they are less flexible on that.  But it's nice that they offered me the option of returning for a refund on a custom order.   You are making me change my mind now 😀

This thing with the tubes not seated properly can cause failure seems bizarre to me. If this is indeed the root cause, I would argue that it is a design flaw.   As you mentioned in your previous post, the fact the tube sockets are sunken in below the surface can be problematic.  You can't see whether your tube is properly inserted.   You can only go by feel.  Being a newbie with tubes,  I tried to be extra careful of not using too much force, worrying that I might break the tube.   I think Cary should have better documentation on how to insert the tubes.

Let's see how it goes.   Hopefully it's a minor issue.