Taming the Class 5 Head a bit

[surfnorthwest]

I had some luck with a 12AY7 in V1 - but pulled it to use in an amp that's getting more use. It definitely lowered the gain on the C5 though.

I tried one too but didn't like the results, took away alot from the amp.

[GuitarBuilder]

Is your C5 still stock? Have you tried any of the mods?

[Sully]

The only way I can make mine sound good is with an attenuator. The amp is dimed, the attenuator is dimed - meaning the LEAST amount of attenuation it can have. Without the attenuator, the amp dimed is buzzy, fizzy and harsh. It just doesn't sound good. With the attenuator it tightens up everything, rolls off the high buzziness, the bass sounds good, etc. I keep bass dimed, middle dimed, highs dimed, volume dimed, and the attenuator at the least attenuation. Its still very loud and sounds just like a plexi through my 4x12 with V30's.

I hear people talk about how awesome it sounds dimed, but mine is almost unplayable. Is that the consensus?

[Cousin Muely]

on 4 - 6 volume wise for me. I agree, above that it is too buzy. It is still stock with the same tubes. I havent got an amp that hasnt improved with a tube swap so we'll see. Has improved since breakun in the speaker. I play the 50th 1 watts so much I dont get out the C5 muxh lately

[surfnorthwest]

Is your C5 still stock? Have you tried any of the mods?

No real need to mod it, I like it how it is. There is no other amp I own where changing the speakers I use makes such a dramatic difference. I am using a 4x12 that has two G12H-30s and two Vintage 30s... really like that with this C5. Only other thing I did was switch out to a Golden Lion EL84 and Golden Lion 12AX7s.

[langmurf]

Hi... new member here... I have a third gen C5 combo.

The best way to get more headroom, from what I've read, and seen/heard first hand here is: a great 12AX7 in V1 and a 12AT7 in V2. The reason the 12AT7 produces more clean headroom is not because it has a lower gain factor, but because the 12AT7 has a higher transconductance rating than a 12AX7. (Pretty sure was transconductance... might be a different spec, but the AT def has a higher rating for what impacts the headroom in the PI position.)

Now... don't think I know what I'm talking about... I don't... I read an article somewhere that I cannot find right now that stated the above... maybe on Myles Rose's guitaramplifierblueprinting.com site.

At any rate, I put an OS Vox branded Mullard 12AX7 in V1 and a JAN 12AT7 in V2 and, man! The headroom is WAY better. Pretty dang clean up to 11 o'clock. Starts breaking up at 12 o'clock... I'll see if I can find that article...

Edit: found the article in question: http://www.guitaramplifierblueprinting. ... verter.pdf

[ClassicRock88]

Sorry to dig up an old thread but I think this one is interesting since I have done the same thing with mine. The Class 5 is a class A amp, so no phase inverter. V1 is the gain stages and V2 drives the tone stack. I put an ECC82 (12au7) in V2 and it sounds great. Dial the treble back, miss way up and bass at about 6. I put the volume on about 7. It sounds very BluesBreaker-ish through its own speaker and very much like a mini 1987 through a 4x12. The 12au7 can handle higher voltages so it doesn't distort the tone stack as much. I dis notice that the eq (which had been very responsive before) had less of a shaping effect on the overall sound afterward. Most of the fizzyness is gone, though. It still retains its somewhat "treble-hot" persona.