View Full Version : TJ Full Music 12AX7 in Croft gear.
First of all, sorry, since I joined this fine forum I seemed to become a Croft junkie !
Anyhoo, I'm not a huge fan of tube rolling and am generally very reluctant to recommend specific valves as this is all down to personal taste and I'd hate too encourage someone to spend their hard earned and then be disappointed.
If anyone is already thinking of trying these in their Crofts however then I would be very happy to give a nudge that way. I've stuck one in my Series 7 and one in the line stage to my 25R and my word the results are quite stunning. They've been in a week now - I find the balance of detail, bass, imaging soundstaging and warmth to be just spot on for me. These truly are the icing on the cake.
I picked this pair up from Lorenz at Wiwi tubes who I'd heartily recommend, paid about £45 for the pair delivered.
I may try a pair in the power supply of the pre too.
Covenant
14-04-2012, 16:53
Looks like they are £80 most places. Does £45 include delivery Ian?
Hi Ian,
Hehehe... That Croft bug bite, she is potent! :eyebrows:
Very interesting about the Full Music 12AX7s... I was thinking of trying their 6SL7s (as my Croft preamp uses the larger octal output valves), see my thread here: http://theartofsound.net/forum/showthread.php?t=17271
Marco.
Looks like they are £80 most places. Does £45 include delivery Ian?
Yes, $69, comes in at just under £44. I understand he's a partner in TJ too. Lorenz really is a good supplier of valves.....
http://www.wiwitubes.com/en/about.php
He did have some RFT EL34 at $150 delivered, very nice valves indeed.
Hi Ian,
Hehehe... That Croft bug bite, she is potent! :eyebrows:
Very interesting about the Full Music 12AX7s... I was thinking of trying their 6SL7s (as my Croft preamp uses the larger octal output valves), see my thread here: http://theartofsound.net/forum/showthread.php?t=17271
Marco.
Obviously I can't recommend these specifically, but if you're feeling flush......;-). Sod my reservations on spending other's money, get 'em ordered !
Riislingen
14-04-2012, 18:27
Using them in my Croft gear as well - lovely valves on all counts !
Covenant
15-04-2012, 16:26
Did you have to adjust the bias in your Series 7 Ian?
Did you have to adjust the bias in your Series 7 Ian?
I wasn't aware I had to - should I be worried ?!
Covenant
15-04-2012, 17:48
I guess if it sounds better-no! The people at Rock Grotto make a big fuss about biasing when a new tube is fitted, those with more knowledge than me please chip in.
No, you don't have to do that with small signal valves, like 12AX7s. As long as you replace like with like, plug 'em in and enjoy! :)
Marco.
No, you don't have to do that with small signal valves, like 12AX7s. As long as you replace like with like, plug 'em in and enjoy! :)
Marco.
With all due respect Marco I do not think that advice may be universally shared. To add to a mention that Jerry (Covenant) gave earlier I suggest that you join Rock Grotto forum and ask their resident guru on such matters, Solderdude. He one of the really good guys out their, knows valves inside out and very willing to advise. There are numerous posts on there about the importance of setting the right bias on such valves on amps such as the Indeed G2 and G3, Project Sunrise and Horizon and Configurable Headphone Amp (CHAmp). I have no knowledge of any other amps so Marco's advice may well be spot on in this particular case but I suggest it may be worth getting a second opinion.
No offence intended, just trying to help :) .
Dave.
The Grand Wazoo
15-04-2012, 23:09
Well, I've been using devices with valves such as Marco mentions for decades and this is the first time I've ever heard of anyone suggesting that one should set bias for them after a simple replacement. Output valves yes, but these? Surely not?
Indeed, Chris... However, it'll be different if the 12AX7s ARE in fact the output tubes, as is the case with the small headphone amps, Dave's referring to, such as the Indeed G2.
Observe this discussion on Head-Fi, for example: http://www.head-fi.org/t/484975/indeed-g2
I got my Indeed G2 today, and tried a few tubes in it and compared it to my modestly modded Bravo (2nd iteration of the first design), swapping tubes between them and adjusting bias each time.
However, that's not the case in preamps or power amps, where bias (if it's adjustable) would be carried out with bigger output tubes (e.g EL34s or KT88s). Indeed, most valve amps now have auto-biasing (or are resistor-fixed), and so no adjustment is needed by the user, when swapping valves of the same type. This is indeed the case with the Croft equipment under discussion, where there is no provision for manual bias adjustment.
In any case, I've asked Anthony TD to clarify the situation, in order that there is no doubt as to the correct way to proceed :)
Marco.
Apologies gentlemen, it would appear that this is another :doh: case of a little knowledge being dangerous. The road to hell ......... etc.
Cheers,
Dave.
The Grand Wazoo
16-04-2012, 08:37
Indeed, Chris... However, it'll be different if the 12AX7s ARE in fact the output tubes, as is the case with the small headphone amps, Dave's referring to, such as the Indeed G2.
That would be so, yes!
anthonyTD
16-04-2012, 09:14
hi All,
All Audio frequency valves need a form of bias to control electron flow and current, otherwise the valve would just draw what it could and self destruct in a very short amount of time, whether they be small signal valves [12AX7,ECC83, ECC88, etc, etc] usual forms of bias are cathode bias,, where there is a fixed resistance placed in the cathode, or Grid bias where there is [usually but not always] a negative voltage [with respect to cathode] actually applied to the control grid, both methods control the amount of electron flow passing from cathode to anode, a bit like a tap controls water, small signal valves are usually biased into class A [or somewhere near] using the cathode resistor method and as such do not necessarily need to be altered when substituting valve types [like for like] however where power valves are concerned, because of the different parameters they may be used in i.e.; high voltage low current, low voltage high current, class A. class AB1, class AB push-pull, single ended etc, it is necessary to have more control over the current draw/ electron flow, this is where it gets complicated, especially when using multiples of valves in output stages, in audio power amps it is necessary to be able to match the current draw of each individual valve in order to minimise distortion etc, this can be done a few ways with either bias system, i.e., using perfectly matched sets of valves that can then be used with the same value cathode resistors, same in grid biased situation where there is only one bias voltage adjustment for the whole set of output valves, or there is the single individual method where each valve has its own method of adjustment, i.e.; separate cathode resistors, or separate grid bias voltage adjustment etc.
Each method has its merits and pit falls, you choose the method to suit the application i.e., whether it be a class A audio power amp or a class B output stage for musical instrument applications or somewhere in between etc, either way' bias controls the amount of electron flow, therefore it controls the set current through the valve.
Hope this helps.
Anthony,TD...
Covenant
28-04-2012, 20:00
I got my 12AX7 from Wiwi Tubes today (titter ye not) and it's installed. I will let it run in for a day or two before judging it's SQ.
Another Frankie Howerd fan I see :lol:
Anyway...... TJ Full-music 12AX7's
I use a pair of them in conjunction with a GE5751 in my phono stage. Very good, I'd say!
Covenant
30-04-2012, 19:52
A big thank you to Ian for recommending the Full Music 12AX7 tube, it lives up to it's name and is indeed very musical. An audio bargain and a true upgrade. Forget about those expensive NOS tubes and try one of these.
Reid Malenfant
30-04-2012, 20:17
Another Frankie Howerd fan I see :lol:
Up Pompeii, Up The Chastity Belt etc :lol:
Superb :D
Covenant
30-04-2012, 21:03
Nay, Nay and thrice Nay!
C'mon.... the valves are not that bad! :(
A big thank you to Ian for recommending the Full Music 12AX7 tube, it lives up to it's name and is indeed very musical. An audio bargain and a true upgrade. Forget about those expensive NOS tubes and try one of these.
I'm just really happy to have helped someone find an improvement for not an arm nor a leg ! Enjoy ;-)
Umm, am i being particularly dumb today? i can find the valves on the wiwi tubes website but no prices or a means of ordering them. Do i have to email/telephone them directly?
Cheers, Si
Umm, am i being particularly dumb today? i can find the valves on the wiwi tubes website but no prices or a means of ordering them. Do i have to email/telephone them directly?
Cheers, Si
Try here: -
http://www.wiwitubes.com/en/product.php?ptype=3&tid=28
Cheers,
Dave.
EDIT: -
Oooops, see what you mean - sorry - looks like you do need to e-mail them. The guy who runs it goes by the name of Lorenz - very helpful and great communications IME.
Dave.
Thanks for the sanity check dave! I'll email Lorenz and see what he can do for me.
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