Tube rolling Cary SLP-05

I recently purchased a used black cary slp-05 to replace a nice classe audio dr-6 that has served me well for the last 6 years. I decided that I wanted tubes in my system again and since I have Maggie 3.7's the thought of tube amps were out of the question.The rest of the system consists of a Oppo BDP-95, mogami balanced xlr's to the Cary pre, audioquest rca's to the innersound esl-300 amp (sanders), and Dave's 14 gauge speaker cables to the Maggie 3.7's The system also serves as a 2 channel av system and for computer audio.

The amp came with some nos ge 6sn7's and stock eh 6sn7's also. The power supply had the stock cheap Russian 5ar4.
It sounded great right out of the box but I had read on this forum and also some others that you are not hearing what this SLP-05 can do without swapping to high quality nos tubes..... so the budget busting quest began. What I have found out over the past 3 months is very surprising to me.

I read as much as I could about the typical sound of the higher rated nos tubes and ended up with the following..
1 matched quad of rca grey glass
3 matched pairs of tung-sol bgrp
3 matched pairs of nos nib vt-231 Sylvania
2 matched pairs of 72 vintage 6h8c Russian tubes
2 matched pairs of cryoed standard EH 6sn7
2 matched pairs of cryoed tung-sol 6sn7 reissues
2 matched pairs of cryoed gold pin EH 6sn7
2 matched pairs of ge 6sn7's '62 vintage (came with the pre)
4 standard EH 6sn7 ( came with the pre)
2 matched pairs of Sylvania chrome top 6sn7gt's (green label)

All of the tubes that were new were ran in for a minimum of 150 hours to allow for proper burn in before I made a judgement on their sound quality.

The standard EH tubes were WAY too bright with the ribbon tweeters in my maggies and it felt like someone was drilling your ears which became unbearable with any volume at all.

I tried the nos Sylvania vt-231's next and they sound good but are VERY bass shy.... not good with already bass challenged maggies ( I do have a pair of velodyne optimum 8 subs that blend seamlessly with the 3.7's).

Next up was the rca grey glass.... WHOA these things produce bass in spades.. so much so that I could listen with the subs turned off. But at the expense of high end extension... just too rolled off.

O.K time to bite the bullet and get some real quality nos (at least everyone claims) so in goes 3 matched pairs of Tung-Sol black glass round plates... WOW this is the best yet! Full bass extension, big soundstage, 3d lifelike midrange, and sparkling highs that don't drill your ears. But these tubes require a second mortgage to buy nowadays and to stock enough to last for many years will be more than the pre cost!

So what else is there to try that is more affordable?

I read about the cryoset tubes and there are 2 groups polarized on these. Those that say they are great and those that say they are total B.S. Well at MUCH cheaper prices for matched pairs than any quality NOS tube I had to try them, so I order 2 matched pairs of standard EH 6sn7.
I popped them in slots 1-2,4-5 and had a listen. I left the Tung-Sol bgrp's in 3,6. Very good all around tube with full deep bass, great midrange and extended highs.... uh oh.... too extended highs. Not nearly as bad as the stock EH 6sn7's
and very listenable at low to slightly moderate volume but at higher volume it is still too harsh at higher volume on my ribbon tweeters. On to something different.

I recently ordered 2 sets of cryoed gold pin EH 6sn7's since people who have tried both the standard EH and the gold pin version claim that the gold pin fixes the high end "drilling" I wanted to see for myself. This is what surprised me. I left the TS bgrp's in slots 3,6 and lit up the new gold pin cryoed quad in 1,2,4,5. It did sound better than the 150-200 hour stock cryoed EH's out of the box. So I started the burn in on them. When I came in from work yesterday I noticed something different about the audio from the T.V. feed that I had left on. It filled the room from wall to wall and had a super deep 3d quality I had NEVER heard in my system. So I fired up the oppo and put in one of my favorite discs and I could not believe how holographic, lifelike, and wide the soundstage was! Something changed at around 60-70 hours of burn in on these cryoed gold pin EH's that made them incredible. In my system these current production tubes trump every expensive NOS tube I tried with the exception of the TS bgrp BUT the gold pin EH's throw a bigger deeper more 3d image than the NOS TS's.... they are like TS bgrp's on steroids, with tighter bass that is not slightly "tubby" like the T.S's
What is weird is the only way that the magic happens is with the NOS T.S bgrp's in slot 3,6..... any other tube set and I tried them all do not sound as good.

I am very happy to have a new production 6sn7 that is this good in my system. It is just a shame that it still needs the expensive NOS Tung-Sols in the balanced input slots to make my oppo cd player shine, but it is better to only need 2 expensive NOS tubes than 6 and I have 2 spare sets already.

I am not affiliated in any way with cryoset but after hearing non cryoed tubes and cryoed tubes of the same type I will NEVER buy non cryoed tubes again.I don't know what the process changes but it makes a big difference in sound for the better.... at least in my system in my room. YMMV

If you own a Cary SLP-05 you owe it to yourself to try a quad of these cryoed gold pin EH 6sn7's You MUST let them burn in for 60-80 hours before they open up but for me they are better than anything I have tried.

Nice story. Where did you source the cryo 6sn7s from and would you be able to share how much you paid?

I also own the Cary pre and think highly of it. I did not consider the stock tubes bright but that could be a system related observation.
They sell them on ebay, they also have their own site. The company is called cryoset. I don't know if pricing is allowed on the forums but the matched pair gold pin EH 6sn7's are $59.95 USD. Considering that top quality NOScan ost 5-10 times as much nowadays I consider this a bargain when they sound better in my setup.

The 3.7 magnepan ribbon tweeters are known to be bright when not set up properly or used with the wrong equipment. I had a set of Maggie 1.6's previously and with a bryston amp it was bright, with a modded st-70 tube amp they sounded great.
I will also add that for these to sound like they do in my system only the Tung-Sol black glass round plates in the balanced buffer (3,6) brought out the magic from the oppo bdp-95. None of my other tubes made the combo sound the same... even TS bgrp's in all slots does not compare with the sound of the cryoed gold pins in 1,2,4,5. All cryoed EH tubes was too much (too bright).
I also forgot to mention that I replaced the stock 5ar4 with a 1959 vintage mullard Blackburn plant piece and it tightened up the bass. I actually did this before I started rolling the 6sn7's

Have you tried the RCA input jacks in lieu of XLR? I find it preferable to use the RCA inputs. And then it matters not what is in the balanced buffer sockets.
Yes I used the rca inputs first from my oppo with audioquest cables. When you use the rca inputs you bypass the use of tubes 3,6 in the preamp as they are used only for the balanced input circuit. When I switched to the mogami blanced xlr's the soundstage deepened and the precise placement of voices and instruments improved at every volume level. The inner detail was "muddy" sounding with rca input compared to the balanced input. The rca input sounds very good but in my system the balanced input sounds more detailed and fuller. You also gain 2 more tubes to roll and experiment with. I have not tried the balanced output from the pre to the amp but I will try that next.I have also read that other users preferred the rca's to the balanced with the 05 but that is not my experience in my system.

Hi Dave,

I also replaced my 5AR4. The stock item was a SINO 5AR4. I replaced it with a no-frills (US$12) Sovtek 5AR4, with good results.

As to the question of balanced vs. unbalanced inputs I believe the result depends on the rest of the system. If any single component in the system is unbalanced then run the entire system unbalanced is my general advise. Don't be fooled by the connectors. There are many components with balanced connectors out there that are not really balanced at all - internally converting to unbalanced.

I run my SLP-05 unbalanced with simply wonderful results.
I went through pretty much the same process & ended up selling a box of approximately 80 of the 6SN7 tubes on Audiogon.I now use 6F8G tubes except for the prime position which is the pair to the left of the headphone tubes where I installed a pair of British BL63 Marconi's which were used by the RAF from 1938 to around 1942.This setup beats any of the myriad 6SN7 tubes I tried in all parameters. For 6F8G tubes I liked the Kenrad the best followed by the National Union and Tungsol round plates.
Lwin I guess you used the adapters they sell on ebay to use 6f8g tubes? If so the adapters did not degrade the sound any?

Dave: There is no way to tell if the adapters degrade the sound because you can't use the tubes without them. But I tried all the best 6SN&'s & in my system the 6f8g's with adapters won hands down. The one thing that can cause an issue is the thickness of the top cap wire; it can be difficult to fit the adapter into the slot if the wires are too thick. Also be aware that the quality of the adapters varies, I have had more then one that was DOA but the frustration is worth it.
For those of you who wish to stay with the 6SN& tubes, the two I found were the best were Sylvanias made for the US Navy during WW2 ,they had a metal base & some also had an anchor printed on them. Very close were the Russians Melz 6N8S/1578 also metal based and the best were marked OTK. These tubes are hard to find and they are not cheap.