Anyone care to offer advice on ECC82/83 alternatives?

Hey folks,

I'm thinking about changing some of the tubes around on my amps and would appreciate any advice you have.

With regards to pre-amp tubes, I'm happy to follow the herd and pay a premium for Mullards. The Romulus uses 3x ECC83 and 2x ECC82. The TubeBox uses 2x ECC83. Currently, the Rom pre tubes are Chelmer/CVC 83's and NOS Philips 82's. The TubeBox uses stock Pro-ject tubes (I assume they're JJ/Tesla, as Pro-ject is manufactured in the Czech Republic)

A few quick questions on the pre tubes:

1) I assume they do not need to be "matched" in terms of emissions & gas content etc. ?
2) There are quite a few different types of Mullards around! What is considered to be the best, and next best?
3) Is it really worth changing the 83's in the TubeBox, seeing as the OP stage is a cheapo, non-discrete, resistor-laden PCB? (Amazing it sounds so good, considering how bad it is!)

The power tubes are Sovtek 6L6GC's (although according to the Romulus spec, I should be using WGC's - is there an important difference? They certainly sound alright). I have it on good authority that these are a good all-round 6L6 and might not need changing. Any views on this?

If not, what is considered to be the best all-round 6L6GC/WGC? My preference would be for something lean sounding & agile in the bass department, as the Romulus is a bit overpowering in the mid & upper bass region. Or ,is this best adjusted/tuned via the bias settings (which, according to the previous owner, was set dead at 35ma, the "bassiest" setting, apparently?)

Cheers,
DT

 

Are the 6L6 tubes the nos Russian ones of ebay ny any chance?? I have these and they are a great tube. Ive played around with the bias of these toobes and I ended up at 35ma but if you want a slightly leaner sound try 30ish.

 

Depending on your unit, you might find E80CC to be a considerably better alternative than the ECC82 - I've successfully used Valvo gold-pin E80CCs in place of the Mullard ECC82 in the second position on my Minimax preamp. However, it depends on the design of your kit as to whether this will work or not.

 

I don't have much experience in valve swapping, all I have done is swap the cheap chinese ecc83's in my 834p phono for sovtek 12ax7lps, made quite a difference (for the better). The groovetubes mullard replicas seem to be getting lots of favourable mentions, might try them soon. NOS mullards etc. seem a bit pricey to me, but I havent heard any=)

 

I'm quite interested in this as well, as I had been contemplating playing around with the preamp tubes in my Copland; it's currently got Edicron ecc83's and Golden Dragon ecc82's. I wanted to try NOS Mullards also but the prices on ebay are putting me off!
Everyone seems to think that Mullards are best, does anyone not agree?

 

Depending on the valve type, you don't necessarily have to be looking for Mullards. For instance, whether it be labelled Mullard, Siemens, Philips or Valvo, the E80CCs were typically all made by the same factory and then labelled accordingly. So, a bit of research might open up alternatives which are essentially the same valves.

 

I do not agree

'bet you knew there would be one' !!

I personally put more importance on buying valves which have been measured and graded for performance in key areas by a knowledgable and well equiped stockist than on brand value.

My comparison would be buying an expensive light bulb that makes noisy humming noises constantly, and then goes pop after 6 months.

A while ago I replaced some vintage and expensive off the shelf valves with no-brand german valves which had been carefully selected from a large batch for quality, in all important areas.

Obviously they are better.

 

Ha ha, well yes!

But assuming you could find some operationally perfect/acceptable Mullards (there must be plenty about, they don't have a reputation for being unreliable), would they sound better than your German ones? I'm more interested in the sound side than ultimate reliability, although obviously I don't want anything that will create unwanted noise!

I suppose the only thing to do is for me to stop waffling on about it and try some alternatives out!

 

hi!

it is difficult to buy vintage tubes that have been subjected to multiple quality control tests - such as microphony, vacuum tests, output tests etc.

No matter what the brand/age of a valve only a small percentage will measure near ideally.

Its been my experience that stockists don't measure and rate their vintage valves, they are more interested in selling all of them at high prices rather than sorting them for quality.

I'm sure if you bought a large quantity of vintage valves (say 50 for example), and then tested them all professionally you would find four or five that measured as well as my valves..... these 4 or 5 may well sound better than the ones I have. I wouldn't swap you for the other 45 though!!

 

Thanks again guys, I know tube rolling can be a pretty dry topic of conversation, so I do appreciate your input.

There seem to be plenty of branded 6L6GC's about: The TAD's look the most interesting of the current production. Seem to be designed for guitar amps though: http://www.tubeampdoctor.com/produc...products_id=814 .

NOS 6L6GC's from Raytheon, GE, RCA etc. are a little bit pricier (£20-£30 each). I'll certainly consider them though. Most of them seem to be in the US, which is a bit of a pain.

TAD also do premium ECC83's, but I am quite keen on trying out the low-gain NOS GE 5751's (£19 at tubeshop),in the pre-amp slot, in order to get my vol pot nearer the magic 12. Would these be OK to use in the phase splitter role too?

Mullards & Tele's are maybe a little too pricey on reflection, especially as I need 3 of them!

DT

 

personally i'm a huge fan of the rca "cleartop" 12au7 (ecc82) they are also MUCH cheaper than mullards or telefunkens.

the brimar cv4002 is also supposed to be a bit of a gem.

as far as switching the 82 for an 83, extreme care should be taken. the 83 is a higher current tube and equipement has to be able to handle the extra draw. the minimax happens to have been over specced so it can handle this. there are others that can also do this, but proceed with caution.

 

Mullards are not always best.

As jtc says E80CC are really good in place of ECC82, but they do draw extra current.

5751, esp 5* black plate are good in place of ECC83 esp if you want to lower the gain.

Try 5881 instead of 6L6, and if you measure the voltage, then maybe KT66 may be OK and they will sound even better.

Also I would really agree with Chris re matched, picked modern valves being better than dodgy NOS off of eBay.

 

Could you name a couple of good reputable UK stockists? Thanx.

 

Well, I'm certainly not considering "swapping 82's for 83's". My 82's are NOS Philips/JAN.

AFAIK, the 5751 is an 83 variant.

Lilolee, I'm considering the GE JG-5751. They seem to go for £12-20 each and have a good reputation. Are the "five star black plates" much more? What is the difference between these and the JG's?

DT

 

http://www.vacuumtubes.com/12au7.html

look here for more detail on tube types...

 

Hi,

There are a few stockists that measure, grade and match their valves prior to selling.

Try CVC (chelmer valve company), and ask about their different grades of valves.

Most valve stockists will give you empty silences or poo-poo remarks if you ask them what methods they use to test and grade their stocks.

 

Excellent website Blakeaudio - cheers!

DT

 

no problem. i've actually bought from him too. he's very good. i will say again, i really like the rca cleartops and for the money they are a steal!

 

OK, I've e-mailed Chelmer about getting a matched quad of GE 6L6GC's, or perhaps the 7581/a variant. FWIW, 7581/a seem to be very expensive - $200+ for a matched quad! Not sure about that!

I've also asked them for a quote on a matched trio of GE JG-5751.

There was an RCA "Command" 5751 on eBay the other day, but I missed it by a few hours. Went for $34 in the end.

Rgds,
DT

 

OK folks, thanks for all your help.

Everything has been ordered and I have plumped for the following tubes:

"Cryogenically treated" GE 5751's for pre & phase (£18 each - Watford valves)
Philips 7581a matched quad (£75 delivered - Chelmer) for the output section.

OK, so they're expensive compared to their historical cost (probably pennies), but I think £125 is reasonable in terms of my wider system. All the Romulus needs now is a better vol pot & switchgear.....

DT