Discussion in 'Amps and Cabs' started by Bossanova, Mar 1, 2015.
I think it's time I replaced the tubes in my Twin Twelve, what do you recommend for them?
Mine still has the original tubes in it. I haven't fired it up in a while, but I think they came with RCA preamp and GE power tubes.
If you want modern tubes, I would try Genalex Gold Lion or Tung Sol. For power tubes, JJ.
If their the original power tubes, I'd get exactly what was in it before.
Preamp tubes I wouldn't touch unless they were tested and known to be weak.
Get it benched/tested so you know what's good and bad and replace with same thing. If the old tubes lasted 50yrs I see no reason to mess with a good thing.
Silvetones are super easy on tubes. It's no coincidence they usually still have originals in them. Both of my 1482's have originals and sound great. Tung sol is definitely the best new production tube on the market for the money. I've yet to have a problem with them. Great punch and articulation.
For cost effective modern tubes, Svetlana 12AX7s and TAD 6L6WGCs. For NOS, JAN Philips 6L6WGBs, RCA or GE 12AX7s, etc.
My 1484 was loaded with RCA....and i know they were original.
I have used different tubes out of my horde in this amp......these are low plate volt amps similar in tone to my 63 Tremolux....dark and thick.
If I were going NOS I would go JAN Phillips 6l6WGB's as Mike K mentioned...best bang for the buck NOS 6L6 type.
Your more likely to see a Silvertone that just needs electrolytic caps and service than tubes because most of them saw very little use for the last 50 years.
Also helps they came with good tubes to start with.
Be very suspect of a tech who tells you an amp like that needs new tubes as soon as he sees it.
TAD short bottle 6L6's sound great in them, and are as close as you'll get to the original style in new tubes(someone correct me if I'm wrong).
But if it were my amp, I'd recap the entire power supply if it hasn't been already. Tubes and more sells a cap can that should fit in original location, it's a 20-10-10, original was 20-10-5, but you'll be fine with that. It's around $35 I think, but should last as long as the original one, and easier than fitting 3 caps inside the chassis. Buy the smaller 100mfd-160V caps for the rest of the power supply. You don't need 450V caps there, and they are hard to fit anyway. Replace the bias cap too.
If u raise the uf on the cap can, it will stiff up the tone and you will lose the sweet sag....depending on the tone u like. I would replace with 22uf, 10, and 4.7uf 450v. Very easy to find online. mount them underneath with zip ties.....leave the can for looks. If you don't like the brightness of new filter caps (be aware, it will definitely brighten up the tone), you can just hook the old can back up.
Thanks. Although I have to admit that last post might as well have been written in Chinese to me..!
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Silvertone 1484's also use two 6CG7/6FQ7 preamp tubes:
One is V3--- the Phase Inverter
The other is V5---- the Reverb Driver
I currently have two 1484's that I've returned to service (both were inop when I got them).
All functions now work on both heads, even the Reverbs (such as the 1484 Reverb is).
Orig transformers, replaced Filter (all filter caps on one and just the axials on the other) and Bias caps----- all new rectifier diodes.
New cathode bypass caps in preamp of one (slightly decreased value to limit a bit of bass in a dark amp) and left the orig ones in the other.
Replaced badly drifted resistors as needed in both amps.
I'm running pairs of good testing used current production 6L6GC output tubes in these heads---- GT branded JJ's in one and Sovteks in the other.
I like to use good testing RCA/GE 6FQ7/6CG7's in these amps but I got some NOS EI's a few yrs ago that also work well.
For 12ax7's I usually go with RCA 12ax7a's but I'll try anything that sounds good in these amps----- including new production Tung Sol's, EH, Sovtek LPS, JJ's, and the many Chinese 12ax7 tubes. Used Sovtek 12ax7WA's run the Trem just fine.
As long as the preamp tubes are not microphonic and the output tubes bias up to decently match the amp (bias not adjustable in these)--- It's hard to make these 1484's sound bad.
It's a good sounding amp circuit...................... gldtp99
Here's one of them:
I just checked the back of my 1484 and it has 2 different powertubes, one is a westinghouse 6l6gc and the other is blank... And they are 2 different sizes and according to my father its all original, is this true?
His father bought it for him at Sears in the 60s