Half triode question...

[tribi9]

If this were mine I would put the normal channel from a black face Deluxe Reverb in this chassis. I don't know what kind of PI is in this circuit but I am sure a long-tail-pair would drive the 6V6s harder. Use both halves of V1 ala Fender DR - You can use the existing front panel for the volume treble- bass. Rewire the Pi to match the same circuit. Keep the cathode bias or go fixed.

Interesting. I was thinking of maybe building a 5E3 in there...

[greekie]

Before you totally rebuild the amp:

What is B+? What does the bias measure?

Is the 15" speaker loud connected to one of your other amps?


It could be the speaker - the tubes - the power supply.

[tribi9]

Before you totally rebuild the amp:

What is B+? What does the bias measure?

Is the 15" speaker loud connected to one of your other amps?


It could be the speaker - the tubes - the power supply.

Im not going to rebuild it, I will check all those. If I do end up changing anything it will need to be anything that can be feversed easily.

[rdjones]

Not sure if the proposed change would work or not. It appears to be a triode in series topology but no attentuation in between and no second triode plate load resistor if I am interpreting it correctly.

Putting them in parallel is a no-brainer though. Do the cathode as you suggest, jumper pin 2 to pin 7 (grid to grid) and pin 1 to pin 6 (plate to plate) and give it a whirl!

Good luck!
Dave O.

Would I need to half the plate and cathode resistor values?

On Fender amps where they paralleled 7025 halves on the first stage, the cathode was reduced to 680 Ohms and the plate load was cut to 47k.

[rdjones]

Generally agreeing with other posts, a lack of output level is almost certainly something in the power stage, power supply or speaker.

Is this a Norelco speaker ?
They were somewhat inefficient and not voiced particularly well for guitar.

rd

[Wiktor D]

I had one of these for a while and it was plenty loud. I love the traynors, built like tanks. My bet's on the output tubes.

Vic

[tribi9]

Generally agreeing with other posts, a lack of output level is almost certainly something in the power stage, power supply or speaker.

Is this a Norelco speaker ?
They were somewhat inefficient and not voiced particularly well for guitar.

rd

The speaker is a JBL D140F. I tried a set of good 6V6's (The metal ones) in there and it is a bit louder but not much more. Haven't taken any measurements as I haven had time. Should be able to this week. The bass is really overkill for guitar tho'. I have a 7025 on V1 and a 12aX7 on V2

[greekie]

Everything is suspect - from the PT not delivering enough juice, to the diodes having (perhaps partly) failed, to the filter capacitors needing replacement.

Try to view the amp as modular, and start from the "entrance" of power.