Header Graphic
Dirty-South Blues Harp forum: wail on! > 12AX7 pre-amp tubes
12AX7 pre-amp tubes
Login  |  Register
Page: 1

Mikeb
19 posts
Aug 25, 2014
6:18 PM
I've got a Bassman RI which is currently being modded to bring it closer to original '59 specs (lower voltage transformer, changed tone stack etc)

I use a Squeal Killer anti-feedback box and I use all 12AX7 tubes as recommended by the SK guys. I don't bother with low gain tube substitutions because the SK controls the feedback anyway

My amp tech has tested my tubes and found they are pretty worn out. So my question is, has anyone got any recommendations for NOS 12AX7 tubes which sound good for harp? Or am I kidding myself and they all sound the same?

Also, has anyone had any experience with the "NOS Tube Store" which is based in Turkey? They seem to have a very impressive range of NOS tubes

Cheers
Mike
1847
2089 posts
Aug 25, 2014
6:30 PM
worn out tubes can be just fine
just turn the amp up a notch
as long as they are not microphonic
use your ears.

----------



i get a lot of request when i play my harmonica
"but i play it anyway"
LSC
672 posts
Aug 25, 2014
9:01 PM
Tube swaps are not just about feedback. A lower gain preamp tube also allows the volume to be turned up thus making the output tubes work harder which affects tone.

I'm a big fan of NOS tubes. Though there are contemporary tubes which are good value for money, JJ for instance, they still don't match up sonically with a good NOS tube from the US, Britain, or Holland.

For a 12ax7, if you really want to buck the current sentiment, I've found Mullard and Telefunken to be my favorites, with RCA running third. The Mullard is the creamiest of the lot, the Telefunken a bit cleaner and more detailed with the RCA a good compromise. Now I use the 12ax7 primarily for guitar and I know we're talking harp here but I mention those as a reference. I've never found a 12ax7 to work in any amp for harmonica as well as something with less gain. A JAN Philips 5751 is a better choice. Their gain factor is on the order of 70% of a 12ax7. JAN stands for Joint Army Navy. It designates a military grade spec i.e suitable for submarine or tank warfare.

I just took possession of a SJ Cruncher which does in fact use a 12ax7, however a 12ay7 is an option mentioned in the manual. Because I intended to use this amp in reduced volume situations I decided to go for that choice. I installed a Russian made Electro Harmonics that came with the amp and it was okay but had that modern day tube stiffness and lack of depth. I hunted high and low and found in my stash a really nice GE 12ay7. Plugged that in and I was good to go.

For 6l6 output tubes my favorites are the RCA blackplates. Silly expensive these days. I got mine just a few years ago for much less. The Cruncher also came with a matched pair of Sylvania 6l6s that looked to be virtually new. They sound pretty damn good but one day I'll have to teach myself how to bias an amp and do a comparison with the RCA. I've got one pair left.

For a modern 6l6 I have to say JJ are pretty nice and excellent value for money.

The online retailers like Tube Depot are reliable but you pay for it. Still you've got someone to go back to if the tubes arrive DOA. It's much harder these days to find deals on Ebay but they are out there. You just need to look carefully at the descriptions and the feedback report of the seller. I just bought a nice RCA 12y7 for $18 that others were asking $25-$60 for.

As for a retailer in Turkey, sure if the shipping cost don't drive the net price up. Turks are in the main pretty cool people. I spent a vacation there once and got to know some of the hotel staff. Totally screwed over by the bosses but still worked their asses off and kept a smile. Lost a credit card in a Turkish owned internet cafe in Holland. The 12 year old son found it and phoned me to say they had it. His dad had it behind the counter when I came back.

Carrying on with tubes your tech says are dying? Why take the chance? A good NOS tube will last a long long time, won't fail, and costs under $30 and you don't have to pay anybody to install. A tube operating the way it should you would expect to sound better than one that isn't.
----------
LSC
----------
LSC

Last Edited by LSC on Aug 25, 2014 9:08 PM
Mikeb
20 posts
Aug 25, 2014
9:34 PM
Thanks for the great info LSC. I totally agree with you on the theory behind tube swaps, and in the past I have always used lower gain pre-amp tubes in my Bassman so I could turn it up and make the power tubes work harder

When I bought a Squeal Killer the instructions suggested reverting back to all 12AX7's. I did a test comparison between low gain tubes without the SK compared to 12AX7s with the SK and I found that I could turn the amp up much louder with the SK and 12AX7s. Also it sounded better, to my ears.

But anyway that's not really the point of my question. You've given me some great info re the 1AX7s so thanks for that. And thanks also to 1847, maybe I'll just do what you suggest and keep using the old ones while they still work

Cheers
Mike
Mikeb
21 posts
Aug 25, 2014
10:19 PM
Thanks BN, can't argue with that explanation. Low gain tubes mean you've got better control over your amp in that you can turn the amp volume knob up to a bigger number before it starts feeding back, but the physical volume might not be any louder. So the power tubes aren't actually working any harder. Good point

My tests with the Squeal Killer/12AX7 combo showed that not only could I turn the volume knob up to a bigger number before feedback, but the actual volume was significantly louder than with low gain tubes (according to my little recording device). Not sure how it works but it seems to do the trick

Last Edited by Mikeb on Aug 25, 2014 10:20 PM
Mikeb
22 posts
Aug 25, 2014
10:26 PM
Hmm, BN's post seems to have disappeared...
arnenym
302 posts
Aug 26, 2014
12:20 AM
For me a amp is a work horse or a á lá carte - amp.
A harp modified or specific harp amp is a work horse. - made for full band gigs.

SK let the amp work as it is build to work. The amp have the standard voltages in preamp and it make the tone controls work as it is intended to do.
A Squeel Killer sure make a guitar amp to a loud killer harp amp.
It be a "work horse"

A tube swap to lo-mu tubes lower not only lower the gain. It also lower the preamp voltages and make the amp sound and work in a different way.

I like balanced JJ 12AX7 and use them all the time for myself and to my customers.
The difference between NOS and new made tubes i to small to hear in a live situation. I have a couple of NOS tubes i use for harp and guitar gigs or recordings where you have a chance to hear the difference.
NOS tubes is more llike "á lá carte" - tubes for special occasions..

Last Edited by arnenym on Aug 26, 2014 12:22 AM
Mikeb
23 posts
Aug 26, 2014
1:42 AM
good advice arnenym, mine is definitely a work-horse!
Barley Nectar
497 posts
Aug 26, 2014
5:17 AM
Sorry Mike, I felt that the post was controversial, so I deleted it. It was for you so, I'm glad you read it. I get frustrated by the misinformation on the web.
I have been using TungSol current production 12AX7/12AY7's in my customers amps. Have no complaints yet. Buy from a reputable dealer...BN
LSC
673 posts
Aug 26, 2014
6:54 AM
Bottom line folks, if a tube set up sounds good to the person paying the money then it's a good tube setup. My opinions are based on my experience, what I hear, and what I perceived to be differences. Others may feel different and that's cool. It's all subjective which is the nature of art.

----------
LSC
barbequebob
2693 posts
Aug 26, 2014
11:00 AM
I've owned a real '59 Bassman since 1983 that I still gig with and prefer the NOS tubes to most of the stuff that's newer production, tho I must admit, the newer production stuff has made some excellent strides in the last 12 years, but my chief complain about the newer production stuff is that they still don't last as long as the NOS stuff does and on the power tubes, the bottom end tends to get really mushy sounding in a hurry when compared to the NOS stuff.

In a real '59 Bassman, the very first preamp tube is NOT a 12AX7, but a 12AY7/6072/6072A and having the 12AX7 tube is usually better for a more modern guitar player who likes to crank the crap out of the treble.

The 12AY7's I prefer are all NOS and I don't care for any of the new production ones at all and the NOS versions I prefer in this order are the 5 star NOS GE's made in the USA, late 50's-mid 60's RCA's, and the extremely hard to find NOS Tung Sols.

The best of the newer production 12AX7's to my ears are the Tung Sol reissues, the Mullard reissues, and the JJ EC803 long plate (which is closer in sound to the long plate GE's from the late 50's-early 60's).

My hands down favorite 12AX7 is the long plate NOS GE 12AX7 made from the late 50's to the early 60's, which has a big, fat midrange and most of the newer 12AX7's are really 12AX7A's, which tend to be more trebly than a real 12AX7 and from gigs, I can really notice the difference when they're in my Bassman.

I don't do the tube swaps many players like to use because I lose far too much dynamic range that I need because unlike most players, having good breath control also allows you to have a wider variety of tonal colors available to you wheras those swaps just mush out everything and the amp largely loses definition.

----------
Sincerely,
Barbeque Bob Maglinte
Boston, MA
http://www.barbequebob.com
CD available at http://www.cdbaby.com/cd/bbmaglinte
Barley Nectar
498 posts
Aug 26, 2014
1:32 PM
I don't do the tube swaps many players like to use because I lose far too much dynamic range that I need because unlike most players, having good breath control also allows you to have a wider variety of tonal colors available to you wheras those swaps just mush out everything and the amp largely loses definition.

Amen to that Bob! Well said...BN

Last Edited by Barley Nectar on Aug 26, 2014 1:33 PM
puri
153 posts
Aug 26, 2014
8:02 PM
Arne is right that you won't hear lots of difference on the bandstand but still, for me you can feel it and that counts. A nice tube would make the amp response to your technique better, it would help you cut through easier and you'd put it in because you like the certain character of a certain brand as well. There're lots of differences from brand to brand and between ax and ay so I'll never make generalisation about them. My favourite for ax/ay so far is NOS 12ax7 Brimar, pretty strong character, it screams and cuts.
LSC
674 posts
Aug 26, 2014
9:46 PM
Talking briefly to the recording engineer this evening about the dynamics of harmonica and how certain keys really cut. He made the comment that the harmonica is an emotional instrument that the player is physically connected to. You breath through it.

Relative to the thread some players have a preference for NOS tubes and are quite specific as to why. Depending on one's ears and the situation one may or may not hear much of a difference on stage. For those that do, the difference is fairly dramatic. I would submit that a factor in that is the responsiveness of a really good tube. If the tone of the amp is moving the player the player's head locks into things. You're not fighting to get there. And so performance is enhanced. The audience may not hear a difference in tone, most of them wouldn't recognize it anyway, but they will know when the players is being moved and so moving them.
----------
LSC

Last Edited by LSC on Aug 26, 2014 9:48 PM


Post a Message



(8192 Characters Left)


Modern Blues Harmonica supports

§The Jazz Foundation of America

and

§The Innocence Project

 

 

 

ADAM GUSSOW is an official endorser for HOHNER HARMONICAS