Custom Vibrolux Reverb - any tips to squeeze out more Headroom?

Grocer_Jack

It's one of the 90s models with white knobs (35W, 2 x10) and has been 'Moyer-modded' to take it back to what I believe is a Vibroverb circuit. It's my gigging amp and I'm very happy with it, except that it breaks up a touch early. I can live with it, but if there's anything that could be done to give me a bit more headroom it would be of interest. I already swopped the power valves to Svetlana Winged C and that helped. I've tried 5751s instead of 12AX7s in V1 and V2 and they 'thinned out' the sound a bit too much for my liking. So I've got JJ 12AX7s in there now. The Speakers are Jensen P10Rs.

Apart from the above, is there anything obvious that might give me more headroom? Any valves that people swear by? Any maintenance or component changes? (As you can tell I'm not an amp expert).

Cheers All and a Happy Easter! 

jacksparrow

I was going to say try 5751 but you have already tried that, i gigged one of these stock for years, and it used to crunch like a mother f***er, i loved the crunch but the singer was not too happy. lol

No ideas sorry. maybe try a vibrolux reverb silverface or blackface

ICBM

More sensitive speakers. P10Rs are really inefficient.

For example the Jensen Tornado and Electric Lightning are both 97dB, 2dB more than the P10R. That would be like increasing the power of the amp by more than 50%. Some Eminences are even higher, for example the Ragin’ Cajun which is 100dB... that would be like tripling the power compared to what you have now.

Some of these will change the tone of the amp a lot too, which may or may not be what you want - if you don’t, it’s probably better to stick to one of the Jensens.

RiftAmps

Do you want more volume before it breaks up, or do you want later breakup on the volume dial, regardless of volume?

Grocer_Jack

ICBM said:

More sensitive speakers. P10Rs are really inefficient.

For example the Jensen Tornado and Electric Lightning are both 97dB, 2dB more than the P10R. That would be like increasing the power of the amp by more than 50%. Some Eminences are even higher, for example the Ragin’ Cajun which is 100dB... that would be like tripling the power compared to what you have now.

Some of these will change the tone of the amp a lot too, which may or may not be what you want - if you don’t, it’s probably better to stick to one of the Jensens.

Thanks - let me investigate the speakers .

Grocer_Jack

RiftAmps said:

Do you want more volume before it breaks up, or do you want later breakup on the volume dial, regardless of volume?

The former (I think). I run it at about 4 to 4.5 on the volume with the band and it's plenty loud enough, but breaking up. I'd like it to be cleaner at that volume. 

RiftAmps

Grocer_Jack said:

RiftAmps said:

Do you want more volume before it breaks up, or do you want later breakup on the volume dial, regardless of volume?

The former (I think). I run it at about 4 to 4.5 on the volume with the band and it's plenty loud enough, but breaking up. I'd like it to be cleaner at that volume. 

OK, in that case, you want more efficient speakers, as @icbm said.

This will, however, make 4-4.5 'louder' so you will find yourself running the amp on a lower dial setting to achieve the same volume as achieved now.

I'd recommend a mix of WGS G10C and G10C/S

Grocer_Jack

RiftAmps said:

Grocer_Jack said:

RiftAmps said:

Do you want more volume before it breaks up, or do you want later breakup on the volume dial, regardless of volume?

The former (I think). I run it at about 4 to 4.5 on the volume with the band and it's plenty loud enough, but breaking up. I'd like it to be cleaner at that volume. 

OK, in that case, you want more efficient speakers, as @icbm said.

This will, however, make 4-4.5 'louder' so you will find yourself running the amp on a lower dial setting to achieve the same volume as achieved now.

I'd recommend a mix of WGS G10C and G10C/S

Great - thanks. I'll investigate these. Why the mix, and would mixing one of these with an existing P10R be worth trying? 

p90fool

What impedance are your speakers? I have an 8ohm Ragin' Cajun doing nothing if you wanted to try a just-broken-in one at used prices? 

Grocer_Jack

p90fool said:

What impedance are your speakers? I have an 8ohm Ragin' Cajun doing nothing if you wanted to try a just-broken-in one at used prices? 

Will check....thanks

ICBM

They're 8 ohm.

If you put it in the side of the amp under the input jacks it will also balance better when you're carrying it .

Grocer_Jack

p90fool said:

What impedance are your speakers? I have an 8ohm Ragin' Cajun doing nothing if you wanted to try a just-broken-in one at used prices? 

Having looked into it I think I'm going to get a set of WGS to keep a bit closer to the current sound, but thanks for the offer. 

p90fool

No worries