HI Guys,
Don't know if anyone is keeping up with the thread anymore, but I have a problem with my Cortese and I was wondering if anyone might be able to help.
I am getting a spitting static noise through one channel. I have fliped all the tubes and the noise still comes through the same channel. I have a friend looking at it now. He thinks it is one of the adjustable resistors in the line stage. He replaced them, but there is still noise in the same channel. He is going to check connections in the power supply next. He has already checked connections in the preamp and they seem to be ok.
Does anyone have any ideas?
Thanks,
Tom |
Hi Kg,
thanks for your offer :-) I'm actually in the UK.
I picked up a couple of cheapo universals but they only
provide for a 3 digit code.
I will try and find a universal that takes 5 digits.
The problem as far as I can see is that the learning remotes seem to depend on them being able to power down the
unit as they trawl through the codes which might make it awkward.
My remote was working to increase the volume but not the other way. I opened it up to try and fix it and now it doesn't work at all :-(
Cheers Simon |
simon:
you might consider buying a cheapie learning remote such as the universal remote control R7G (URC-R7G) and shipping it to someone who has a functioning supratek remote. i would be willing to program the learning remote with my supratek codes if you shipped it to me, but i'm in america. i'm sure there are some supratek owners in australia who would be able to help you out. otherwise, drop me a line and i'll get you my address information. good luck. |
Eh, I'm hoping the troll bit didn't refer to me?
Mick pointed me to a supplier in Australia but they don't seem to stock them so I'm still looking for a remote that accepts the 5 digit code and works with the Syrah?
My Syrahs always worked faultlessly except for the problem with the cheapo remote handset (nowt to do with supratek really).
Only wish I could say the same for the other Supratek pre I have it's a real pita! |
The tubes I'm using are also from 1942 and 1943 - World War II vintage. I wouldn't worry about the age, they built them tough in those days - after all they had to survive warfare inside RADAR units - much tougher than surviving in your preamp! In fact I dropped one from a height of ~6 feet yesterday onto a hardwood floor while swapping among the different brands; not only did it not break, it still works perfectly. Even if it was to break, they're cheap to replace compared to good 6SN7s!
Great to hear someone else is enjoying the 7193s! There is something poetic about using a tube designed for warfare to produce something so beautiful, isn't there? |
Mr Ait, yes ,here from distant São Paulo ( Brazil), thanks to you and mr Eccletique, I am too running the 7193 in my cortese. the thing is ugly but most beautifull sound ( I am concerned with the age of tje tubes ( 1942 adn 1943 old tubes...I will send the photos thanks Fernando ( they are driving stacked quads 57's... |
I'm curious, too. Do we have someone besides me running these tubes?
By the way, they sound fantastic with my "new" Infinity RSIIb speakers - the EMIT tweeters and EMIM midranges really deliver the clarity the 7193s are capable of. |
Slowhand,
How is the 7193 conversion? |
Mint604,
I have owned a Supratek preamp for years with no trouble whatsoever. NO, I don't sit around staring at the wiring inside of it. I prefer to sit back and enjoy the beautiful music it produces. This is what make me happy. I hope sitting there staring at the inside of your Marantz 7C makes you happy. |
i've seen the internals of my chardonnay, malbecs, and current dual cabernet. true enough they do look messy, but every solder joint looked clean to me. further, all the wires felt "tight" in their positions and not flopping around inside the chassis.
apparently some people only want to see shiny pcb's with thick traces inside their gear. in my experience, the shortest most direct signal path sounds the best. my preamp is point to point wired and so is my amp. even my DAC has a short signal path / minimalist approach (47 labs shigaraki dac).
the other benefit of point to point wiring is it's relative ease of repair. now that supratek has closed up shop, we owners can still have our preamps/amps repaired by a skilled technician. we're not left out in the cold because an oem supratek pcb burned up. |
That last post sounds like a Troll, please ignore it!!
I have owned four Supratek preamps Syrah-Cortese-Cabernet-and-Grange over a period of ten years and NONE have failed. In fact the Cortese that I sold some 8 years ago is still going strong, owned by a musician type, used regularly, never repaired - even the original tubes have not been changed.
The innards are a bit messy due the hand built nature of the thing and point-to-point wiring in the pursuit of short signal paths. If you look at the way the wire is strongly twisted at the solder points, great care and time has been taken.
At the end of the day hard wired valve amps like the Suprateks will last ten times longer than flimsy heat exposed circuit boards.
Steve. |
To keep the dream alive, some further Supratek comments and pics posted here ... http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1146370182&view
Cheers,
Steve M. |
Thank guys will mail Mick.
Simon |
Mine died a couple of years ago, and Mick got me a replacement for a nominal cost. |
shoot mick an email. i'm sure he can point you to a source for the remote. |
Anyone had problems with the select 1 remote & aquired a replacement?
The one supplied with my Syrah has died and I can find no trace of them online. |
Easy Tweak for preamp! - I have been playing with diy active shielded cables ( a la tesla) and tried it on the cortese power supply to pre cable - as it is a copper braid shield I just added a 12v wall wart power supply, 12v LED lamp and connected it to either end of the braided shield - switched polarity to get the best sound. I thought it a small but clear improvement - worth a try esp. if you have that stuff lying around
Cheers |
there's a pair of piano black/chrome malbecs on eBay for $3500 plus shipping if anybody is interested. they aren't mine for what it's worth. i just found it interesting that supratek gear is popping up on eBay. |
Picked up a pair of NOS Tung-Sol 5881 (6L6WGB) tubes for $25.00 at an antique radio swap meet this weekend. They have light brown bases and look to be 1950s vintage. The seller said they tested new, and they looked perfect, so I went for it. I've seen these online for $210.00/pair, and I know they are very popular with the guitar guys, but I figured I'd give them a whirl as regulators for my Chenin.
Verdict: They are an improvement over the stock Sovtek "5881" regulator tubes, providing a fuller midrange and slightly tighter bass, with no noticable ill effects. They are definitely a good match with the 7193 linestage tubes. I don't think I would pay $210 for them, but for $25 they are a nice upgrade. I was thinking of selling them at a profit when I picked them up, but I think they are staying put in my Chenin. My rectifier is a NOS GE 5AR4 (the one with the copper sides). |
Has anyone compared any of the Supratek preamp model against the Cary SLP 05 preamp ? If yes, lease share your experience. Thanks.
Tim |
I just received most of the parts to do the 7193 conversion to my Cortese. I still need to get the wire. I will keep you posted. |
I've been listening to the Ken-Rad 7193s in my Chenin for about a month and one half now, and I decided to try an experiment last night. After listening to a few songs with the 7193s in place, I switched back to my RCA grey glass 6SN7s for comparison.
The difference was quite startling! The sound I used to think was very warm and full (the RCA 6SN7s) now sounded quite constricted and flat, compared to the 7193s - they just have so much "air" and sparkle at the top end that the 6SN7s just can't match.
It was back to the 7193s in very short order for me! I don't think I'll be repeating that experiment any time soon. |
National Union vs RCA vs Ken-Rad 7193 tubes.
Since I have converted my Chenin to 7193s, I have been evaluating the different brands of 7193s available (in addition to enjoying the great sound!). Let me say that they are all excellent tubes, but there are some subtle differences between them, both in sound and in construction. All have black, relatively flat plates, with small boxes in the center.
National Union: The NUs have the smallest bottle of the three 7193s, and the getter is not visible from the exterior of the tubes. They have a round top and bottom mica. These were the first 7193s I ever heard, and they sound very good indeed. These are silky smooth, with a rich midrange. They are a little rolled off on the extremes compared to the other two tubes, but it is a not a huge difference.
RCA: The RCAs have a larger bottle than the NUs, with a bottom getter and round top and bottom mica. They have more extended highs and lows than the NUs, with fuller bass and a little more detail on top. Not quite as smooth as the NUs, and not quite as warm in the midrange.
Ken-Rad: The biggest bottle of the three, slightly larger than the RCA, with bottom getter and non-round top and bottom mica (looks like a round mica with a section cut out in each quadrant). The best bass of the three - the impact of kick drums is sensational, and bass lines can be felt and heard in great detail. The highs are nice and airy, with very good detail, and the midrange is very sweet as well.
So overall, in my opinion, I would rank the 7193s as follows:
Ken-Rad: best overall - it has everything
National Union: smoothest and warmest sounding, but a little less top and bottom than the others
RCA: Similar to the Ken-Rad, but not quite as smooth in the highs. |
Thanks Ait. Yes, our Chenin are different from each other then. Mine uses 6C4's. Great project you have there! That's a nice Tuner! I do not use my Chenin anymore. In fact it is on the sideline now. Maybe when the mood is right, then I will have the urged to listen to it again. Yes, I like the Chenin but like you put it, my Chenin is "so last week" also. Just kidding, I love the preamp and I am very happy that I invested my money on it. On my system page is the preamp I recently built. This is what I use nowadays. You can also see it on this link http://img177.imageshack.us/img177/1681/img4095gy6.jpgor http://members.myactv.net/~je2a3/friends.htm my system is at the very bottom of the page. Have fun tweaking then! regards, Abe |
OK, Phono section tubes: 6688 (E180F - Philips SQ) 6922 (stock EH) Rectifier (NOS GE 5AR4 with the copper sides - niiiiice) Regulators (stock Sovtek 5881) Linestage (well, we've been through that, huh?) Want to see my latest project (the Chenin project is so last week; yes, I'm Maxamillion over there): click here: Awesome Tuner Get One NowI cannot believe that this tuner I picked up for $15 at a junk store is this good! Un f'in believable! |
Okay thanks! So it means that the triode in the 6SN7's are Directly coupled and both seems to be voltage gain stages.
No, I was not asking for changing the OP of the Chenin. Apologies if somewhat my statement sounded like that. All I am saying is, the preamp now run the 7193's using the Chenins 6SN7 designed PSU. So, it is possible that the change in sound is from variation of the operating voltages typical for a 7193 like changing its PD (Power Dissipation) due to different bias levels from that optimized or selected by Mick for the 6SN7.
Apologies again, I am not asking for a pics of the internals, just the outer layout. I just want to see what tubes were use in your Chenin since as far as I know, there are three versions (not sure but two I am pretty sure) of the preamps phono section and can be distinguish by what tubes being use in conjunction with the 6922's.
Thanks!
regards,
Abe |
The anode of the first 6SN7 triode stage is connected to the grid of the second stage in the Chenin. The output wires in the stock version are connected to anode II and cathode II.
I did not change any operating voltages in my Chenin. The only thing I did was move the two output wires from II to I, and plug in the adapter with the 7193s. From what you say, maybe varying the voltage might produce even better results, but my aim was to keep the Chenin as close to stock as possible, yet still able to run 7193 tubes.
Sorry, but I hesitate to pull the Chenin out of my system, open it up and take internal pictures at this point, since the only internal change is moving the two wires. |
Hello,
First of, thanks Ait for sharing your findings. I appreciate the time you took to explain to us what you did.
After reading the post of using 7193 in place of the 6SN7's, I have a few quetions.
1.) Does the change in sound could be accounted for using a 7193 with the 6SN7 Operating Points? For example, if Mick is using around 240V at the plate (max for 6SN7 is 250V), then it means that the 7193 will now be bias soft (300V at the plate max) or quite in a conservative region. If so, will it be safe to assume that when you do this, you changed the original Supratek OP already and instead, what you have done is using the PSU of the Supratek to run 7193 tubes?
2.) Does anyone know if both triodes in each 6SN7's on the Chenin are being use as voltage gain stage or one as a CF (Cathode Follower ) only?
3.) Would it be too much if the original poster can post a clear pic of his preamp.
Apologies for my inquiries but I have an access to a 7193 preamp and I remember that the OP that sounds best in that specific circuit is around 275 to 280 volts on the plate with the Grid V around 8~9 volts. Just wondering and wanted to learn, that's all.
regards,
Abe |
Does anyone have Kevin Covi's most recent contact info.
His email address @attglobal.net bounces back.
Please send me a PM.
Thanks in advance |
I just finished an extended listening session, and a few things stood out with the NU 7193s.
The highs are extraordinarily detailed and sparklingly clear. They might be fatiguing if it wasn't for the total lack of glare - these tubes are clean, clean, clean. This probably has to do with the anode and grid connections being through the top caps, a design feature which was adopted specifically to improve high frequency performance in radio frequency applications, according to several on-line sources I have found.
The mids are very natural and warm, but not as warm as those from the RCA Grey Glass 6SN7s, which some might consider overdone. The harmonies on the Beatles "Love" CD were thrilling.
The bass is about the same as I had with the 6SN7s, maybe a bit tighter. I'm looking forward to receiving the Ken-Rad 7193s (which should have been here by now...) as Ken-Rads are well-known for their prodigious bass. Stay tuned. |
Just to clarify, no holes need to be drilled in the preamp! I was asked this question in an off-line email, so I thought I should post a clarification. I specifically designed this mod to make the fewest possible changes to my precious Chenin (they don't make these any more, ya know!), especially irreversible changes such as hole drilling. The wires from the top caps go into the tube base of the adapter and connect to two of the tube base pins, which then make the appropriate connections with the Chenin's internal wiring through the Chenin's 6SN7 tube socket. The ONLY mod to the preamp itself is to move the two output wires from the connections for triode II to the connections for triode I. |
Hi Gang. Hey...Kudos to Ait for his post on the 7193 conversion. Well thought out and very well written.
Kgturner. While the conversion is certainly do-able.... I rather doubt you would reap much of a benefit[if any] from this conversion anyway. The job of the 6sn7 in the circuit of your Dual was chosen for a very different role.
That said: And trust me here KG [as this is a simple a no-brainer move] Swap out the 6sn7's in your Dual for a pair of old stock Kenrad VT-231's [the black glass versions] The quality of bass reproduction from the Kenrad is simply majestic, and unmatched by any other tube in the 6sn7 family.
|
I understand, Kg. Even though I thoroughly studied the circuit and went over the mod dozens of times in my head before I did it, I still had quite a bit of anxiety when I pushed in the power button. Happily, there was no factory smoke released. |
very interesting. now that supratek is defunct, i wondered how long it would take before modifications to the circuit started being proposed. while i am naturally intrigued by this, i don't think i'll mess with my dual cabernet if for no other reason than the sheer terror that would befall me frying the preamp. |
I originally posted this as a separate thread but am re-posting it here at Slowhand's request. I have been intrigued by the 2C22/7193 tubes since reading about them in the "Supratek Tube Swappin'" thread, especially the comments from Audiogon member Ecclectique, who described them as "magnificent". I was not, however, interested in totally rewiring my Chenin in order to use them. So, after thinking about it for a while I came up with the idea to make socket adapters for the 7193s, using new tube bases, ceramic tube sockets, ceramic tube caps, and rubber-coated hookup wire. How did it work out? In short, GREAT! The 7193s are spectacular in both sound and looks (with their cute dual top caps). The gain of the tube is lower than that of the 6SN7, but I had WAY too much gain anyway - I only ran the Chenin on the low gain setting with the 6SN7s, and I had to switch my Gilmore amp to the low gain setting (20dB gain) to get any usable range on the volume control. With the 7193s, I have the Gilmore set to high gain (27dB) and 12 o'clock on the volume dial is about 85-90dB at my chair. The gain switches behind the 6SN7s on the Chenin no longer do anything after this mod, since they only attenuate the second triode of the 6SN7. The following two links have pictures of the completed adapters and the Chenin with the adapters and the 7193 tubes installed. AdaptersCheninOne minor wiring change needs to be made to the Chenin in order for this to work: the two output leads (one has the big Auricap on it) that connect the 6SN7 tube socket to the output transformer on each channel need to be moved from Anode II (pin 2) to Anode I (pin 5) and from Cathode II (pin 3) to Cathode I (pin 6), respectively, since the 7193 is a single triode tube. This is a very easy job - there is plenty of room in the chassis, even for a ham-fisted guy like me. The reward for this minor change - glorious sound!! The 7193 is a spectacular tube, with airy highs that seem to float into the room, a nice warm midrange, and solid, tight bass. Best of all, the National Union tubes I am using retail for $5.00 and change from AES!!! They are pristine new-in-box JAN tubes, dated June 1943, with all the printing intact. I'm getting sound at least as good as the very best 6SN7s almost for free!! I have RCA and Ken-Rad versions of this tube on order so I can compare the sound, but the NUs are certainly no slouch. They kick the hell out of the RCA Grey Glass VT-231s I was using previously. If you are still uncertain, how about this fact - you can still use your 6SN7 tubes without moving the wires back! Just remove the 7193s and adapters and plug the 6SN7s right back in! You will only be using one of the triodes in the 6SN7, but that still gives plenty of gain to work with, at least in my system. In fact, I think the 6SN7s sound better this way than with both triodes hooked up. If you don't like the sound, simply move the two wires back to where they were. Details of the adapter wiring: Anode of 7193 (top cap) to Anode 1 of 6SN7 socket (pin 5) Grid of 7193 (top cap) to Grid 1 of 6SN7 socket (pin 4) Cathode of 7193 (pin 8) to Cathode 1 of 6SN7 socket (pin 6) Heater 1 of 7193 (pin 2) to Heater 1 of 6SN7 socket (pin 8) Heater 2 of 7193 (pin 7) to Heater 2 of 6SN7 socket (pin7) Remember, all pinouts are looking at the bottom of the tubes/sockets, with the index pin detent at the top; the pin numbers increase from 1 to 8 in a clockwise direction. You can obtain data sheets for these and many other tubes online from a variety of sources. Hints: Drill holes in the tube base to pass the two top-cap wires through. Be certain to actually test-fit the bases into both of your Chenin's tube sockets and mark where you want to drill the holes - the other tubes might interfere with the top cap wires if you don't put the holes in the right places, plus you probably want to make the placement of the wires symmetrical on both sides, and the Chenin sockets may not both be aligned in the same way - it's always better to measure than to do it twice. Tin the wire ends that go into the tube base to prevent loose strands from accidentally short-circuiting the adapter. This also allows the wire to form a bond with the entire pin after the pin is heated with the soldering iron. Make the wires between the tube base and the socket as short as they can be while still allowing you enough room to guide the wires into place and solder them. There is not a lot of room inside the tube base when the sockets are pushed into place inside the base, so you need to arrange them so the socket will fit to the proper depth. Only three of the pins from the socket are used for this adapter, so I snipped off about 2/3 of the length of the unused soldering tabs and bent them over to prevent them from touching any of the other tabs when the socket is pushed in. I didn't snip them off completely since the pin holders on the other side would then fall off. I coated the socket tabs and the base pin holes with a high dielectric conformal urethane coating (from a local electronics shop) and let it cure until it was no longer tacky before pushing the sockets into the bases to help prevent any accidental short circuits. I used a two-part epoxy to seal the sockets to the bases - just coat the base on the inside and push the socket right into it. It is a nice tight fit. I then clamped the two together with a C-clamp for 24 hrs until the epoxy was completely dry. Re-check the pinouts before you use the adapter, just in case! This can be done by checking continuity with a multimeter. Materials: I sourced the tube bases, ceramic sockets, and small (1/4") tube caps from The Tube Center in Orlando, Fla. The wire used was Belden rubber coated hookup wire #8899 from Newark Electronics in Palatine, Il. If you try this, have fun and enjoy the results! Disclaimer: You do this mod at your own risk as I cannot be certain of the setup of all of your Supratek preamps. I know this mod works for my preamp. Please check your preamp thoroughly and verify the correct pin locations before attempting. |
Markxiii
The spindle does not go through to the back so the only way would to be run a gear drive on an extended shaft between knob and pot( I think I have seen a picture of that somewhere) and there is not enough room in the chassis for that. I lost remote but sit quite close so it was not a big issue. You probably have seen the bent remote for dact but it would not fit either.
One of the advantages of the RK50 is that if you do set the volume too high it does not get into that ear bleeding teritory - just gets louder ( my experience)
Cheers |
Pjwd, do you know if the RK50 pot can be somehow adapted for use with an external motor (like the 4.5V unit that moves the standard Blue Alps)?? |
I didn't look for the thread for a while and I was saddly surprised by Mick's decision. As a proud owner of a Chenin and a pair of Malbecs I want to thank Mike for many hours of pure pleasure and wish him the best of luck on his new endeavor. Mike: you should try to grow some Malbec down there! It's a wonderful grape. Best, Pablo. |
Fiddler,jmr and other "mad upgraders" - I have followed your lead and replaced the volume pot with the Alps RK50 ( on cortese) - definite improvement - fuller sound, sharper edges, lower noise floor - much more "live" sound - not sure if it is better than the dact but had a ARC ref3 in my system while ago and while it was not as musical as the cortese it had a lot more body and heft - the alps pot seems to go some way to providing that without losing musicality - now looking at selector switch - anyone had a go at replacing that
Cheers |
Guys, I'll also throw in shipping and handling.
On second thoughts why sell an absolute classic. What could I possibly replace the Dual with? It's taken me almost a decade to get to this point in my pursuit of hi-fi bliss. I mean let's face it, how many other pre-amp manufacturers make a product like the "Dual" (two in one effectively)?
I may just hang onto this little baby like a 1955 Penfolds Grange.
Sorry everyone. |
Does that mean that you would pay %9000 for my Chenin? Bob |
i'll throw in shipping & insurance within the US only. act now, and i might even consider splitting the paypal fees!! :P |
Is shipping and insurance included?... |
Just to add a little competition to the mix, I'll be willing to off-load my Cabernet Dual for $14.5k |
i'll sell you mine for $15k. i might even throw in a power cable at that price. :) |
Anyone want to sell their Cabernet Dual? Bob |
I did not look into this thread for a while and what a unpleasant surprise.
Suratek is out of the bussiness. That very sad news.
I was kind of hoping to read the great posts about Supratek MONDEUSE... Does anybody got it, any listening impressions ? |
Hi Mick,
It was a very sad moment last week when I went into the Deal of the Century thread in A'gon to keep up to date with fellows supratekies comments and news and I read the news of your dismissal of the Supratek operation. Your reasons are totally valid and in any case the decision is absolutely yours. I join all the others in expressing my best wishes for success and happiness in all your future endeavors both personally and professionally together with your loved ones. I am totally sure that your passion and dedication will yield a successful outcome.
The timing is particularly off because I had read somewhere of plans by you of attending as an exhibitor to the next Rocky Mountain Audio Fest in Denver, Colorado next October, and I was looking forward to meet you and experience a complete Supratek electronics set-up. Although I am very happy with my present amplification I confess that your amps. where always tempting, and in the back of my mind .... By the way this show is very enjoyable due to it's nature of being geared to the audio enthusiast and not for dealers and distributors and therefore I would think,very fitting for you; I have gone the last two years and enjoy it very much; your participation this year was the excuse for attending again, now I am not sure ... I think that If you ever decide to come to one of these USA shows you should let it be known, I am sure that many of us would enjoy meeting you.
Again, thanks very much for your passion and dedication and for the legacy of these artesian pieces of electronics and am sure I join many others in hoping that before long you may find a way to bring Supratek back; if you do, please let us know. For now, the audio world is at a lost .... Wish you the best !
Best regards,
Jose Rodriguez |
OT: Ping Stiltskin!
Hello Mark,
I hope you received my email(sent weeks ago)to you regarding how wonderful the tubes I got from you are!
Thanks again!
regards,
Abe |
Mick: It is very sad to hear these news. Hope you and your family the best. As far as Puerto Rico- there are Supratek owners and fans.
Manuel Vidal |
