Use Marshall PB100 Power Brake alongside Bugera PS1 Power Soak

[d3vCr0w]

Hi people, hope you're all doing great. I was wondering if it's possible to use an amp (in this case a Marshall JCM 800 2210) with two attenuators at the same time, I have a Bugera PS1 Power Soak but I don't really trust it to handle high volumes/output because it gets warm and I fear it overheating, that's why I got myself a Marshall PB100 Power Break, it works fine, I can crank the amp more without fearing it would overheat (it has an internal cooling fan) but the problem is that it lacks a Line Out (something that the PS1 has), and that's a feature I like (to use with Impulse Responses). I was wondering if there's a way to use both attenuators at the same time, if that makes any sense and if it would be safe.

The idea would be to split the amplifier's power to both attenuators so neither of them gets warm, and have the PS1 give me the Line Out feature.

I read about modding the PB100 to add a Line Out option but never found at least someone who did it, to see/hear results first.

Thanks by the way.

 

[fitz]

I'd suggest the Bugera in line after the Power Break.
Use the power break to attenuate the amp output, and leave the Bugera wide open (no attenuation) for the line out.
Using one on each speaker out (if that's what you mean) is not going to "split the amplifier's power to both attenuators".

 

[steveb63]

Or add a line out to the Power Brake.

See attached, this is the schematic my amp guy used.

It's Weber's version, but works with the Marshall Power Brake.

 

[d3vCr0w]

Or add a line out to the Power Brake.

See attached, this is the schematic my amp guy used.

It's Weber's version, but works with the Marshall Power Brake.

View attachment 111616

Have you done it? It seems simple enough to do it myself, three resistors, a potentiometer and a jack.
I would like to see pictures or hear a demo of a PB100 with this mod, does it end up being a proper line out? I mean, like with the appropriate signal level and good enough for recording?

 

[steveb63]

Have you done it? It seems simple enough to do it myself, three resistors, a potentiometer and a jack.
I would like to see pictures or hear a demo of a PB100 with this mod, does it end up being a proper line out? I mean, like with the appropriate signal level and good enough for recording?

Yes
I had my neighbor, who is one of the countries top boutique builders do the mod for me.

I added a volume control inline. Levels are fine for recording. I run that line out straight into my interface,

Very happy with the results, no issues and it's been used heavy for about a year now.

 

[steveb63]

Almost forgot.

Resulting signal definitely need speaker sim/ filtering etc...

It is a raw signal that needs to be treated to sound realistic.

 

[d3vCr0w]

Almost forgot.

Resulting signal definitely need speaker sim/ filtering etc...

It is a raw signal that needs to be treated to sound realistic.

That's indeed what I need, the raw signal at a line level to use with Impulse Responses.
What did you use for the volume control?
And could you please post pictures?

 

[PelliX]

I have a Bugera PS1 Power Soak but I don't really trust it to handle high volumes/output because it gets warm and I fear it overheating

Wise decision! 50W is about the max I would want it to handle. Don't forget that your JCM is a high gain amp and will easily push north of a hundred Watts.

I'd suggest the Bugera in line after the Power Break.
Use the power break to attenuate the amp output, and leave the Bugera wide open (no attenuation) for the line out.
Using one on each speaker out (if that's what you mean) is not going to "split the amplifier's power to both attenuators".

Actually, it would. Where is the amp otherwise getting this extra power (energy) from? You would get the output of, what, 100 - 140-ish Watts divided by two when using the same tap. Different taps and the load will be a bit skewed of course. Also, the PS1 (unfortunately) doesn't do "zero attenuation", it's 50% - 100% by design. No bypass switch either unless you put one it (not hard, either).

Putting two attenuators in series is not going to do the tone any favors, though. I found the line out on the PS1 to be ... let's say disappointing, but if it works for you then I'm glad!

As outlined, adding a line out to the PowerBrake is not a bad idea, maybe do that anyway so you can compare and pick whichever you prefer? Also, even if you're only pushing 50W into the PS1, a fan wouldn't hurt it either...

 

[d3vCr0w]

Wise decision! 50W is about the max I would want it to handle. Don't forget that your JCM is a high gain amp and will easily push north of a hundred Watts.



Actually, it would. Where is the amp otherwise getting this extra power (energy) from? You would get the output of, what, 100 - 140-ish Watts divided by two when using the same tap. Different taps and the load will be a bit skewed of course. Also, the PS1 (unfortunately) doesn't do "zero attenuation", it's 50% - 100% by design. No bypass switch either unless you put one it (not hard, either).

Putting two attenuators in series is not going to do the tone any favors, though. I found the line out on the PS1 to be ... let's say disappointing, but if it works for you then I'm glad!

As outlined, adding a line out to the PowerBrake is not a bad idea, maybe do that anyway so you can compare and pick whichever you prefer? Also, even if you're only pushing 50W into the PS1, a fan wouldn't hurt it either...

Yeah, before getting my JCM 800 I had a DSL100H and used that one a couple of times with the Bugera PS-1 but always with a 12V fan blowing air out of the unit just to be safe.

 

[JohnH]

Most line-out circuits take their signal from the input that comes from the amp. So if you like the Powerbrake but don't want to mod it, just wire the line-out with pot, a couple of resustors and jacks in its own small box. Plug that into a spare amp output jack and use the PB in the other. The circuit that @steveb63 posted above would work fine.

 

[d3vCr0w]

Most line-out circuits take their signal from the input that comes from the amp. So if you like the Powerbrake but don't want to mod it, just wire the line-out with pot, a couple of resustors and jacks in its own small box. Plug that into a spare amp output jack and use the PB in the other. The circuit that @steveb63 posted above would work fine.

Would that be better than using the built-in DI Out that the JCM 800 2210 has?

 

[JohnH]

Would that be better than using the built-in DI Out that the JCM 800 2210 has?

Actually, maybe it'd be the same! I just had a look at the schematic and it seems like the DI out is on a pot, and unlike many DI's there is no attempt and tone compensation. If so, its exactly what an IR will expect to see once you set its level. - see at lower right:

 

[Tatzmann]

It'll sound the same or minisculy different.

As much as i'm with you on your 800 journey,
those d.i. stunts won't bring you any of the benefits of a big ol' Marshall.

It'll never show its teeth without sheer volume.

 

[d3vCr0w]

Actually, maybe it'd be the same! I just had a look at the schematic and it seems like the DI out is on a pot, and unlike many DI's there is no attempt and tone compensation. If so, its exactly what an IR will expect to see once you set its level. - see at lower right:

View attachment 111703

So the DI out is actually after the power section, pretty much what the speakers get but at a lower level (line level, right?)

I don't get why many people say it's unusable, I guess maybe they thought it would sound 'good' as it is, like going to a mixer and... done. It sounds 'bad' because it's the raw unprocessed signal, it's meant to be shaped afterwards (with IR's for example).

Alright, according to that, I don't see the need of modding the PowerBrake to add something that the amp already has (maybe the resistors values are not the same but it seems to be a line-out as I need it to be).

 

[JohnH]

That's right. At the time of the JCM 800's there wasnt anything as effective as an IR to get you a good DI sound, and raw would sound bad. Hence many might note it as unusable. But worth trying now with new IR tech!

 

[junk notes]

It'll never show its teeth without sheer volume.

!00% the truthhhhhh!