New Tubes/Rebias?
- Thread starter tenniso
- Start date
casblah
New member
Re: New Tubes/Rebias?
You really should re-bias when changing output tubes. Biasing balances the current going thru your power tubes. I'm not an electronics technician, but I successfully re-biased my late 60's Super Reverb. Fortunately, it has a bias control potentiometer. It was simply a matter of using a bias probe device with a digital multi-meter and adjusting the pot from there. Many amps require resistor value changes to properly set the bias, and therefore are a bit more involved. I'm not aware of what your Deville has to set it's bias. As far as tubes go-- I've had good luck with JJ/Teslas, both in pre-amp, and power amp versions. They seem to be good tubes which are readily available; unlike new-old-stock tubes which tend to sound good, but are also a small fortune to purchase. You don't have to bias your amp for pre-amp tube changes, though a balanced tube for the phase inverter wouldn't hurt. Someone will be along soon with much more knowledge, and can give you further advice. Hope this helps a bit.
You really should re-bias when changing output tubes. Biasing balances the current going thru your power tubes. I'm not an electronics technician, but I successfully re-biased my late 60's Super Reverb. Fortunately, it has a bias control potentiometer. It was simply a matter of using a bias probe device with a digital multi-meter and adjusting the pot from there. Many amps require resistor value changes to properly set the bias, and therefore are a bit more involved. I'm not aware of what your Deville has to set it's bias. As far as tubes go-- I've had good luck with JJ/Teslas, both in pre-amp, and power amp versions. They seem to be good tubes which are readily available; unlike new-old-stock tubes which tend to sound good, but are also a small fortune to purchase. You don't have to bias your amp for pre-amp tube changes, though a balanced tube for the phase inverter wouldn't hurt. Someone will be along soon with much more knowledge, and can give you further advice. Hope this helps a bit.
Thames
Great White Malice
Re: New Tubes/Rebias?
Blues Deville dont have any bias adjustment whatsoever, and almost impossible to tweak the bias circuit.
However, Torresengineering.com has a nice kit :
http://www.torresengineering.com/fenbluesdevn.html
Blues Deville dont have any bias adjustment whatsoever, and almost impossible to tweak the bias circuit.
However, Torresengineering.com has a nice kit :
http://www.torresengineering.com/fenbluesdevn.html
Gearjoneser
Gear Ho
Re: New Tubes/Rebias?
Thames beat me to it. I don't think that amp has an adjustable bias. It's probably set to a median point like 32mA, which is right in the center of the ballpark.
Tesla JJ's usually pop right in and bias right up to the preset bias level.
I'd go ahead and replace the preamp tubes too, just so the amp sounds equal or better than it did when new. Read up on pre tubes, to see what suits your best.
Personally, I'm digging the GT 12AX7C's the most. Nice punchy gain with no flubbiness in the lows.
Thames beat me to it. I don't think that amp has an adjustable bias. It's probably set to a median point like 32mA, which is right in the center of the ballpark.
Tesla JJ's usually pop right in and bias right up to the preset bias level.
I'd go ahead and replace the preamp tubes too, just so the amp sounds equal or better than it did when new. Read up on pre tubes, to see what suits your best.
Personally, I'm digging the GT 12AX7C's the most. Nice punchy gain with no flubbiness in the lows.
Re: New Tubes/Rebias?
ok, i checked my tubes and they are as follows: power tubes are Sovtek 5881wxt and the pre amp tubes are Sovtek 12ax7wa.
i am looking for that classic fender clean sound and a warm yet crunchy overdrive(not a gain maniac marshall kinda sound).
so what do you guys suggest?
ok, i checked my tubes and they are as follows: power tubes are Sovtek 5881wxt and the pre amp tubes are Sovtek 12ax7wa.
i am looking for that classic fender clean sound and a warm yet crunchy overdrive(not a gain maniac marshall kinda sound).
so what do you guys suggest?
inter
Member
Thames
Great White Malice
Re: New Tubes/Rebias?
tenniso,
Get those Sovteks out of this amp immediatly !!
You might find the JJ a tad darker for your Deville, unless its really what you're looking, you might loose some of that Fender crystal clean sound. Ei would be a better choice, but they are prone to microphonics. However, the Ei Gold Elite versions are "pre-tested" versions and shouldnt be a problem.
EH might be a good choice too. My choice would be a EH in V1, JJ in V2/V3. For the 6L6s, JJ and SED are the best current production tubes.
For max clean headroom, put a 12AT7 (or 5751) in V1.
tenniso,
Get those Sovteks out of this amp immediatly !!
You might find the JJ a tad darker for your Deville, unless its really what you're looking, you might loose some of that Fender crystal clean sound. Ei would be a better choice, but they are prone to microphonics. However, the Ei Gold Elite versions are "pre-tested" versions and shouldnt be a problem.
EH might be a good choice too. My choice would be a EH in V1, JJ in V2/V3. For the 6L6s, JJ and SED are the best current production tubes.
For max clean headroom, put a 12AT7 (or 5751) in V1.
Gearjoneser
Gear Ho
Re: New Tubes/Rebias?
Yeah, my Bogner sounds best with GT12AX7C's. I've put everything in the preamp stage of that amp, and the 9th Gen Chinese beats them all, which is why Mr. Bogner chooses to use them as stock. Of course, he buys the non labeled ones for much cheaper than GT sells them for. Ive seen non labeled ones as cheap as $5.50 a piece on Ebay.
Also, I like the new GT mullards, but only in amps that have a natural breakup like my Chieftain or a plexi. I have GTM's in the 1st and 2nd gain stages of my Matchless Chieftain. Sounds exceptional! These same tubes sounded a little muddy and overboard in the Bogner. The C's are tighter and have almost as much gain and volume.....half as much money, too.
Sovtek finally nailed it with the 12AX7LPS. Better than all the other Sovteks and Electroharmonix, which are actually good Sovteks, relabeled. Good smooth gain and nice and warm. I wish I had a bunch of these.
I only have one, and funny enough, I put it in my Vox Valvetronix AD60 head, as the single tube that sends it's tone to the SS power section. I noticed a slight improvement under my fingers, after replacing the stock Sovtek 'A' with the LPS.
Thames said:
Yeah, my Bogner sounds best with GT12AX7C's. I've put everything in the preamp stage of that amp, and the 9th Gen Chinese beats them all, which is why Mr. Bogner chooses to use them as stock. Of course, he buys the non labeled ones for much cheaper than GT sells them for. Ive seen non labeled ones as cheap as $5.50 a piece on Ebay.
Also, I like the new GT mullards, but only in amps that have a natural breakup like my Chieftain or a plexi. I have GTM's in the 1st and 2nd gain stages of my Matchless Chieftain. Sounds exceptional! These same tubes sounded a little muddy and overboard in the Bogner. The C's are tighter and have almost as much gain and volume.....half as much money, too.
Sovtek finally nailed it with the 12AX7LPS. Better than all the other Sovteks and Electroharmonix, which are actually good Sovteks, relabeled. Good smooth gain and nice and warm. I wish I had a bunch of these.
I only have one, and funny enough, I put it in my Vox Valvetronix AD60 head, as the single tube that sends it's tone to the SS power section. I noticed a slight improvement under my fingers, after replacing the stock Sovtek 'A' with the LPS.
