General tube question

[heiney9]

I know both driver tubes, output tubes and rectifiers affect the final sound of a tube amp. Here's my current questions. I recently got a new tube integrated amp using (2) 6SL7's for driver tubes and (4) 6V6GT's for the output tubes.

These are all current production tubes made in Russia the 6SL7's are Tung Sol and the 6V6S are JJ/Tesla. The bass response is pretty lean compared to my Dared MP5 hybrid integrated, especially at low level listening. If I really get on the volume the bass improves a little bit.

Both unit are in the 12-15wpc range, running my modded 5B's and I know they are capable of better, deeper, more solid bass.

1) which area will get me more bass the driver tube or output tube? or both. I do plan on replacing all tubes with vintage tubes.

2) since the amp was damaged in shipping I am currently unable to use the 8 ohm tap. Is there a possibility that the 8 ohm tap will give more bass?

Just looking for some opinion's...........I'm sure I'll find out soon enough when the vintage tubes start arriving and I start rolling.

H9

[thsmith]

H9, no expert with tubes but what I have witnesses on my Anthem AMP 1 was finding the right output tube to get the right bass was key and the driver tubes made the tweeks to get rest of the way on clean tight bass.

I found the bass on the JJ KT77 to be boomy, went to SED WING C EL34 and Ei 6CA7 made for nice tight punchy bass.

Have RCA cleartop 12AU7s and went to Mullard CV4003 made a nice improvement on the bass and finally I have Brimars that give me everything the Mullards did but with more sparkle on the top end.

FOr me, output tubes make the big changes and the power tubes the subtle but noticable changes

[madmax]

My old pre used a different tube (6922) and I could go from very lean bass to very powerful bass with different manufacturers tubes. It may be very different for the 6sl7's.
madmax

[doctor r]

H9, My experiance has been the output tubes have the most effect on the ultimate sound output i.e. bass and treble extension. The driver tubes will massage the flavor -treble extension, bass tone, mid sweetness, ect. As far as the speaker connection the 4 ohm output could theoretically improve bass control with a slightly higher damping factor but I found my 7bs with upgraded crossovers and 6503 drivers sounded better overall with the 8 ohm outputs from my EL34 based amps.

[mhardy6647]

The output transformers can have a great effect on the LF extension and distortion, too. OPTs are one case where bigger is almost always better (at least in terms of LF response). The amount of negative feedback (if any) will also affect the LF rolloff.

So, if you're not using the 8-ohm taps, which taps are you using? 4 or 16? (I don't know what amp you're referring to, sorry). If you're using the 4, try the 16, or vice versa.

Generally (and, of course, all generalizations are false, including this one) the small-signal tubes will impact "sonics" more than the output tubes. Coupling caps and other passives in-circuit can have a pretty significant impact, too, of course... and of course the LF rolloff will depend on the value of the coupling caps used.