Questions about vacuum tubes

dhart86

recently I've been enjoying the sonic presentation of tubes. I have a lite audio dac 60(modified Pacific Valve) It uses 6922 tubes. My first question is in regard to NOS tubes.

How much difference does it make if you buy tubes that are "matched"?
What would be the problems if they are unmatched?

I also bought a tube buffer for my secondary rig. It uses the (2) 6sn7 tubes.

Could you guys give me you opinions on good tubes to try. I know that it is based on your musical taste, but I listen to Jazz, acoustic piano/guitar, some R&B, some Rock

Thanks for your input

Equipment is Rotel 991, Lite Dac60, Sony cx3--, LSi 7

2nd rig Adcom 545, Musical Fid v-dac, (Chinese) 6sn7 buffer, Lsi 7

zingo

Matching tubes is important if the same output is required from each tube, or if a single tube is not doing the entire amplification process. I always suggest matched tubes expect when you have adjustable bias output tubes.

NOS tubes can have great sound quality, but also tend to require great sums of money. My choice for an upgraded 6SN7 would be the Shuguang Treasure CV181-Z as I love the Treasure tubes in my amp. A good budget option would be the Electro-Harmonix 6SN7 Gold.

heiney9

Matching tubes for input/driver tubes isn't as critical. Anything within 10-15% is unoticeable. The goal is always to find as closely matched tubes as possible but with used old stock tubes and wide variations in tube testers and user methods it's hard to find. I never worry about it unless there is a large discrepancy.

With new production tubes from a reputable dealer you can pay extra for matched tubes and even matched triodes within those tubes, it's up to you but I have over 100 pairs of tubes (mostly NOS) and have never noticed when they didn't match exactly or within 10-20% for that matter.

Fixed bias output tubes are a different story, they need to be closely matched for best performance.

H9

heiney9

I know many people will plug new production tubes as being as good as old production stock, but I don't feel that way for the few new production tubes I've used. I prefer NOS tubes by a pretty wide margin.

6922 and 6SN7 tubes, the good ones, are going to be a little more expensive.

H9

P.s. For me personally I wouldn't choose the links in Zingo's post...........but that's just me.

F1nut

Brock, you really need to try the Treasures.

zingo

Agreed. The Shuguang Treasure and Psvane tubes may not be a good as the best NOS, but they can also cost less, come with a warranty, exactly matched, etc.

Shuguang Treasure CV181Z - vacuum tube: Head & Shoulders above the rest?

heiney9

Guys, I admit I am gun shy when it comes to new production tubes, ESPECIALLY Chinese tubes. There isn't a single new prod. tube I've tried other than Winged C EL34's that has really come close to the best NOS tubes.

Since you both have suggested it, I'll look into the Treasure's, but they will have some very tough competition.

To the OP a couple suggestions for 6922 tubes would be the Valvo E88CC (herleen made) and Mazda E88CC (french made). I have a source for these NOS, matched for $150/pr plus shipping.

H9

F1nut

The Treasures don't come close, they exceed.

Be forewarned, they have a painfully long burn in.

thsmith

F1nut wrote: »

The Treasures don't come close, they exceed.

Be forewarned, they have a painfully long burn in.

Jesse, I am about to pull the trigger on treasure KT88s. I hope they are as good as I have been reading.

I have the vintage Tung Sol 6550s in my amp now.

To the OP, I like the RCA (red base) or Hytron (brown base) 5692s for 6SN7s.

I may have to give the 6SN7s Treasures a try as well.

heiney9

One of the best 6SN7's in the 1950's D-getter or Square getter Sylvania WGT's short black plates known as the "chrome dome's" because of the heavy chrome flashing. The later versions are great as well but not quite as nice as the 50's.

H9

zingo

I have also had success with NOS Hyton and Mazda tubes, and have been able to find them for a fair price on ebay (rarely).

zingo

thsmith wrote: »

Jesse, I am about to pull the trigger on treasure KT88s. I hope they are as good as I have been reading.

I can't speaker for their KT88 as I have not tried it, but I currently have the Treasure 300B, 6CA7 (EL34), and Psvane 12AX7, and they are all excellent tubes.

heiney9

I'm willing to give the Psvane 12AX7's a try. You really think they will sound better than the 1957 12AX7 RCA long black plates or the 1958 ECC83 Valvo Hamburg 45* slant getter tubes I already own? The RCA's were a lot cheaper slightly used and the Valvo's were only about 20% more slightly used.

That's where I'm at right now these have the best attributes I love. You really think spending $80-90 on a pair of Psvane 12AX7's is really going to blow my socks off?

Mazda tubes are excellent. Anything from the French Philips plants is excellent.

H9

thsmith

zingo wrote: »

I can't speaker for their KT88 as I have not tried it, but I currently have the Treasure 300B, 6CA7 (EL34), and Psvane 12AX7, and they are all excellent tubes.

I will let you know. I just ordered a quad of KT88 treasures $450 shipped grade a from Grantfidelity.

Jesse has not steered me wrong yet.

Thanks Zingo

zingo

I'm currently doing testing between standard and Psvane Shuguang 12AX7 tubes, and I'll report back with a conclusion when they are all burned in and tested.

I'm not sure I can claim that they Psvane tubes will be better than your favorite NOS tubes, but they are a great option for anyone who can't find NOS or would rather buy used. With the 12AX7 and similar tubes, there are a lot of good/great options out there. But for something like the 300B, NOS because of price and/or availability is not an option for many people, and the Treasure is probably the best option when combining price/performance/reliability/availability

Joe08867

zingo wrote: »

That is pure pornography.

heiney9

zingo wrote: »

But for something like the 300B, NOS because of price and/or availability is not an option for many people, and the Treasure is probably the best option when combining price/performance/reliability/availability

I totally agree!

H9

doctorcilantro

I just stumbled across these on AA, not sure if they are still for sale though.

http://trade.audioasylum.com/ca/listing/Tubes/Shuguang-Treasure/CV181Z-6SN7/-quot-As-New-quot/42735

dhart86 wrote: »

recently I've been enjoying the sonic presentation of tubes. I have a lite audio dac 60(modified Pacific Valve) It uses 6922 tubes. My first question is in regard to NOS tubes.

How much difference does it make if you buy tubes that are "matched"?
What would be the problems if they are unmatched?

I also bought a tube buffer for my secondary rig. It uses the (2) 6sn7 tubes.

Could you guys give me you opinions on good tubes to try. I know that it is based on your musical taste, but I listen to Jazz, acoustic piano/guitar, some R&B, some Rock

Thanks for your input

Equipment is Rotel 991, Lite Dac60, Sony cx3--, LSi 7

2nd rig Adcom 545, Musical Fid v-dac, (Chinese) 6sn7 buffer, Lsi 7

dhart86

heiney9 wrote: »

One of the best 6SN7's in the 1950's D-getter or Square getter Sylvania WGT's short black plates known as the "chrome dome's" because of the heavy chrome flashing. The later versions are great as well but not quite as nice as the 50's.

H9

Thanks Zingo & H9 for the info regarding "matched" tubes.
I actually just purchased a pair of Sylvania WGT's (chromes) but haven't tried them yet. Is there a burn-in factor for NOS tubes?

The Treasures look interesting, I'll look for more feedback. May try them.
I know the Electro-Harmonix 6sn7 is new production (budget) tube, but do they sound decent. Is it worth the time and money?

I really am looking to try the Red base RCA. Damn, this tube rolling......
"they just keep callin me"

heiney9

The red base RCA's are special I have 2 pairs of the 5691 (6SL7) variety. Go for it

5691's are 6SL7 variants not 6SN7 those are 5692

dhart86

I would like to know if tubes need time to burn-in. NOS ? New production?
Thanks

heiney9

dhart86 wrote: »

I would like to know if tubes need time to burn-in. NOS ? New production?
Thanks

Yes, absolutely some more than others. Plan on 50-300 hours with the avg being about 50-75 hours.

H9