Epi / GA5 new modifed Valve Head 'Quick no haggle sale'

[Bogwhoppit]

Sold

[georgeguitars]

god damn i want this amp. damn money. i might pm you tomz if its still about

[nocaster]

Got any details on the attenuator mod?

K

[nocaster]

I originally done the Pentode / Triode mod and while it reduces the power down to 3 Watts, that's still too loud for evening bedroom use. Normally, the Pentode mod would warm the sound a little, but the Marshall mod already gives it warmth anyway, so that mod was there just for the sake of it.

I wanted a power reduction method that was simple effective, cheap and one click. So I made a resistor network in place of a master volume. This allows a massive drop in output power while giving full gain. So at midnight when the kids are in bed, you can have those Hendrix /Page tones at a few hundred mill-watts

In conjunction with the two gain stages, you can up that to evening use and TV use ( three different quiet volume levels on full chat )

So the resistor goes after the pwer stage?

K

[nocaster]

Not quite. It dumps signal to ground prior to the EL84. It's different on the Epi because there is no tonestack. The GA5 has the Marshall tonestack, plus it can be switched in & out, so R15 and R5 values are not the same and are changed according to the mode.

On the Epi you can sling a 500k pot in place of R5 and put the wiper on R15 for a crude(ish ) MV control.

I don't understand how you then get the full EL84 drive if you reduce the signal going in?

Surely that's just a master volume and not an attenuator?

K

[Bogwhoppit]

I don't understand how you then get the full EL84 drive if you reduce the signal going in?



K

Nooo

Full drive on the Pre-Amp V1a > V1b Gain.

You cant have full drive on the output stage without a power soak.

It all depends on your definition of attenuator ?

Did you think I was on about a power soak hooked up to the OT ?, All I am doing is reducing the amplitude of the signal without distorting the original waveform.

[nocaster]

Nooo
It all depends on your definition of attenuator ?

That's probably it.

My definition is a reduction in the signal from the power amp to the speaker therefore giving full drive at lower volumes.

K

[Bogwhoppit]

That's probably it.

My definition is a reduction in the signal from the power amp to the speaker therefore giving full drive at lower volumes.

K

I went to Uni many moons ok .

Either way it works on a practical level which was my aim.

[nocaster]

I went to Uni many moons ok .

Either way it works on a practical level which was my aim.

Cool.

Only reason I ask is that I fancy that mod for myself.

K

[roundthebend]

Dave, with that head plugged into a cab would it be loud enough to play a gig without micing up? Let's say at a pub such as The Norfolk - now sadly an estate agent!