Tube rolling a valve preamp (Icon Audio LA3). Where to start?

horace

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I've had a few tube amps but have never bothered with tube rolling.

My LA3 uses the following tubes:

1 x rectifier - 5AR4 (GZ34) or 5Z3

2 x 12AX7 (ECC83)

1 x 12AU7 (ECC82)

Was thinking of buying a spare set of tubes (just in case) and thought I'd take the opportunity to dip my toe in the uncharted waters of tube rolling.

I'll update this post tonight with the makes of the current tubes (nothing fancy in there at the moment).

If I do the changes gradually, which substitution is likely to make the most significant difference (eg rectifier?). Indeed, just how much difference should I expect to hear? Completely new territory for me.

Not looking to break the bank, as this is a first go.

Cheers

Martin

 

silencio

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JJ ecc803 gold pin are pretty good and would not break the bank. For ecc82 - chrome plated Siemens NOS (will hurt your bank balance), Telefunken ecc82 smooth plates (hurts even more). What would you like to add or change in the sound with tube rolling?

 

Ian

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Despite doing it occasionally I have mixed feelings about tube rolling. It can be expensive for sure and the results can be ‘different’ rather than ‘better’, and discovering this after shelling out hard earned can be frustrating. As can be evaluating I find.

Having said this when I do do it I tend to go for what are considered to be high quality new production (TJ Full Music for instance) or reasonably priced (you benchmark !) NOS.

The much lauded Lorenz at Wiwi Tubes can be your friend. He does the cheapest TJFM for sure and also has other interesting stuff. For instance I’m awaiting a pair of American Military Jan Philips ECC82/12AU7 that he’s doing for £18 delivered.

I always find a decent bottle of the amber stuff is, pound for pound, a more preferable and cost effective upgrade ;-)

- - - Updated - - -

Oh, and get a Mullard GZ34 and be done with it ! Mullard Magic is worth a look.

 

horace

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Thanks silencio and Ian.

I don't have particular improvements in mind, just curious as to the level of difference that can be achieved.

A bit of idle googling suggests the rectifier might be a good place to start. Not sure I'm quite ready for Mullard expenditure yet, but modern JJ (and others - recommendations welcome) are cheap enough to try. If I hear no difference, I'll have a spare. If I am bowled over, I can experiment further. A win / win situation.

Quite easy to empty your wallet on NOS tubes - maybe I should just leave well alone....but hey, you only live once.

Cheers

Martin

 

silencio

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Martin, changes and improvements seem to be not only tube, but equipment dependent, so unless someone has experimented with the exact piece of euipment, it will be difficult to predict. BTW the JJs are new production and not silly money. You may try them too, with little risk.

 

Frizzy brizzy

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Second the call for a Mullard rectifier, will give you the greatest bang for buck.

the 12au7 are cheaper than 12ax7 best value I think are RCA cleartops (really are superb vfm) for the 12ax7 try Ge or tung sol, tends to be American are better value than euro tubes, though IMHO not as good.

i got bug couple years back, be careful to not get carried away, also amps can be choosy about what they like.

i found psvane to be very good, not tried signal size, but they are almost as much as nos.

as far as the German legends, tele 12au7 ribbed are good, not huge diff to smooth plate, 12ax. Too expensive. Fantastic High fi, others more musical.

Mid sixties mullards are good musically if a bit soft on dynamics.

for all round balance amperex, now getting pricey,

seimens too expensive to all but the committed and those of deep pockets. But IMO the best.

ask you dealer what he likes, might save heartache.

 

horace

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Thanks everyone - plenty of food for thought there.

I think I'll start with cheaper modern types and move tentatively forward from there.

Might also try contacting Icon Audio to see if they have any tips. Can't do any harm - they know the amp, after all.

Cheers

Martin

 

Chivas

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Thanks everyone - plenty of food for thought there.I think I'll start with cheaper modern types and move tentatively forward from there.

Might also try contacting Icon Audio to see if they have any tips. Can't do any harm - they know the amp, after all.

Cheers

Martin
Good idea, I've always found David Shaw and co very helpful and pragmatic. And after all, they must've experimented with dozens of valves when developing so should be in the best position to advise.

 

AlanB

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From my experience tube rolling will/can give more than subtle changes.

As said earlier they are very equipment dependent and very much personal taste as are all things in life.

At the moment, in my system, I am getting great results with Siemens E82CC's - not as expensive as one would think at £52 a pair delivered and Siemens ECC83's.

Beware of TJ's. They have a fantastic 'Wow!' factor but can be fatiguing over the long stretch.

 

da22222

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From my experience tube rolling will/can give more than subtle changes.As said earlier they are very equipment dependent and very much personal taste as are all things in life.

At the moment, in my system, I am getting great results with Siemens E82CC's - not as expensive as one would think at £52 a pair delivered and Siemens ECC83's.

Beware of TJ's. They have a fantastic 'Wow!' factor but can be fatiguing over the long stretch.
Hi Alan...Are the siemens E82ccs you refer to the 3 mica S& H 1960's types or the later Siemens (no 'Halske') '80's ones?

 

diceman

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Of all the tubes, I have found the small signal tubes to give the greatest difference over power tubes.

Improvements are purely subjective but can be had and IMHO subjectively tune a system to your liking. Improvements in dynamics, fullness of bass, taughtness of bass, air and space, imaging accuracy/width & height of soundstage can be gained - rarely all together though. As people have said changes are available which may be substantial improvements to your ears.

For bang for buck the russian type tubes always seem to be a good start point, (tube amp doctor stuff is normally russian origin IIRC) TJ full music in my experience can be really bad and noisy or bring welcomed deatil and air depending on the bit of kit they are used in. IIRC there has been some comments that they have smaller pins than normal and hence can be noisy depending on valve holders used in your kit.

Old mullards - not for me but provide more warmth.

Telefunkens - yet to hear a bad one although others can be better in different circuits.

There are often low miles (semi-NOS) tubes available for sale in the used section and well worth borrowing or buying some used signal valves as they last ages.

As for the Mullard GZ34 - most comments on the internet are based on use in a circuit designed for its use, modern tubes have higher internal resistance and result in lower voltage as a result which moves the operating point. If your amp is designed and built around cheaper modern GZ34 alternatives the gains may not be so great as regularly reported.

If you can borrow one and see as they are quite expensive.

 

Ian

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Beware of TJ's. They have a fantastic 'Wow!' factor but can be fatiguing over the long stretch.
A comment from a very experienced/knowledgeable (read obsessive ;-) ) tube roller in Alan that interests me. I favour the TJ very much but will be comparing the Jan Philips when they arrive and Mullard later. I'll let you know...........

I am interested in those Siemens though. Told you, it's a nightmare !

 

da22222

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A comment from a very experienced/knowledgeable (read obsessive ;-) ) tube roller in Alan that interests me. I favour the TJ very much but will be comparing the Jan Philips when they arrive and Mullard later. I'll let you know...........I am interested in those Siemens though. Told you, it's a nightmare !
yep, the 3 mica S&H 1960's- though not cheap- are one of the best I have used over the years in my SET and pre amps; first rate tubes and often very tight, balanced sides. Just be careful, the 70's-80s cheaper incarnations are a different, leaner animal altogether though some do still try to price them absurdly high...

 

horace

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I suppose it would help if I told you which tubes are in the amp at the moment:

5AR4 - marked 'Electron Tube. Made in China'.

The 12AX7s are Electro-harmonix.

The 12AU7 is marked '5814A USA'.

Does that help?

Having had a listen last night, I reckon the preamp errs slightly toward brightness. If anything, I'd like to warm things up just a touch.

Cheers

Martin

 

AlanB

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The 82's are non Halske and, I think, 1986. But the 83's in the dac are Halske. Strangely enough the ECC83 non-Halske are warmer than the Halske.

5814A USA? Are they GE? EH 12AX7's have always sounded a bit hard in my amps/experience.

Clean for one ear is warm for another.

Example:- One or two visitors have said my systems are Pipe and Slippers yet others have said they are not P & S at all. :clout:

 

Jazid

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Just to add to all the discussion above don't forget that a Mullard GZ34 will be most unlikely to lose any significant value, and might well make you a scrap of money over time. New production won't, its money lost even if the sound is fine. I personally would go for the 12ax7 (ECC83) tubes for biggest rolling effect (at largest cost), but the ECC82 is a relatively cheap tube to buy and should certainly bring something to the table. I'd go for a tested tube with balanced sections over one allegedly NOS, and a properly tested one as well. New stock often comes tested and matched IME, old stock is at best variable and same date codes don't guarantee anything without provenance (and I've never seen that given). Some idea of budget might help as well.

You're welcome to PM me and I can sort you a selection of less grand appearing ECC82s that measure well to try for sensible money :)

Or some silly money ones that will get nods of approval from the great and good hereabouts as well :D

 

June

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I have mixed feelings about tube rolling. It can be expensive for sure and the results can be ‘different’ rather than ‘better’, and discovering this after shelling out hard earned can be frustrating. As can be evaluating I find.
Agree very much with this, having spent the last year frenziedly tube rolling small signal valves and learning the hard way that its all so much very dependent on the circuit implementation in your amps. What tubes work for me may just be a big meh for you.

Failure - buying a pair of chrome/nickel plated Siemens 12AU7 only to realise much later that this was being in my phase-inverter stage; any sonic benefits of these tubes (and many users rate them well) are redundant as there's no actual amplification happening at this stage.

Swapped them out for a pair of 60's RTC CV4003 / 12AU7S box plates which do the phase-inversion well, leaving the Siemens to do DAC duties (if I ever get around to buying a DAC that is).

Disappointment (mild) - not all vintage 12AX7 tubes are necessarily better than good current production 12AX7; marginal benefits for bigger costs (not grumbling; though that is the hifi game I suppose).

Disappointment (definite) - 5751 tubes and in particular the 'legendary' Sylvania Gold Brand (grey plate -gold pin & black plate -steel pin variants) which over emphasise the mids and push everything else out to the sides.

Neutral - RCA 5963 red-tips; made for computer applications but not bad at all as a sub for 12AU7. Good with female vocals and cheap to buy.

Win - late 50's Siemens & Halske CCa for my preamp; gold pins / grey risers and touted as 'legendary' tubes; preferred these to the gold pin Telefunken CCa; good but in my preamp the benefits were not as much as I'd anticipated over Sovtek 6922 tubes.

Win - GE black plates over GE grey plates

Win, Win - 50's Westinghouse long plate 12AX7; great tubes and won't break the bank.

Win, Win, Win - the three Amperex 12AX7 tubes currently in my phonostage; pre-Bugle Boy manufactured in 1954 with welded plates; not cheap and near impossible to source, these trounced every other make I tried (late 50's Amperex Bugle Boy, 1960's Bugle Boy, Telefunks 803S, Mullard CV4004, Brimar CV4004, Brimar 12AX7, pre-war Ei 12AX7, RCA black plates, GE GL-5751 5-star black plates, GE JG-5751, both types of Sylvania Gold Brand 5751, Raytheon windmill-getter black plates and a plethora of currently made 12AX7's). Well worth the time and and money invested.

Have fun.

 

Jazid

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Actually I'd definitely swap out the EHs first as they're rather often accused on forums of brightness, and for my money I'd try to get a pair of NOS Tesla (not JJ) 32 or 37 code box plate E83CCs. These have the frame grid and are spectacular and long lasting tubes, often considered in the same company as the legendary Tele ECC803. Currently they are not cheap but available and IMHO undervalued.

 

June

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Actually I'd definitely swap out the EHs first as they're rather often accused on forums of brightness, and for my money I'd try to get a pair of NOS Tesla (not JJ) 32 or 37 code box plate E83CCs. These have the frame grid and are spectacular and long lasting tubes, often considered in the same company as the legendary Tele ECC803. Currently they are not cheap but available and IMHO undervalued.
Good call. The 32 codes are from the Vrchlabi factory and 37 from Trinec.

Many prefer their 70's productions to 80's and Roznov made tubes (code 33) to both.

 

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