Master Volume (options for non-MV amps)

thisisguitar

Hey guys, 

Have any of you taken a non-mv amp and had it modded to some sort of Master volume?

I've been looking at London Power Scaling, seems an appealing option. Any thoughts? @martinw @ICBM

I am full of questions at the moment :-)

ICBM

Get an attenuator.

Totally non-invasive and retains the power supply dynamics, which is part of what makes a pushed non-MV amp sound good. Though they are harder on the power valves, which is their main disadvantage.

Power scaling sounds like a slightly superior MV, to me. Not worth the extra complexity, alteration and cost unless you're building the amp with it from the ground up.

In my opinion...

thisisguitar

Thanks @ICBM - Have an Ultimate attenuator which I'm going to replace the noisy fan on tomorrow, so I'll give that a try. As usual I'm trying to find the simplest approach for gigging.

Though some would argue that not running two amps in the first place would have done that :-)

ICBM

I don't like the "Ultimate Attenuator" (which is neither ultimate nor an attenuator, it's a solid-state re-amp system) at all, sorry! I thought it was average-sounding at best and poorly designed and built.

I apologise since you own one . But don't judge all attenuators by it, and don't use it with any amp which needs a lower impedance than 8 ohms - possibly 16, with some - no matter what its maker claims.

There are many proper attenuators which sound better, are simpler (no power supply needed) and aren't as likely to break or damage your amp...

thisisguitar

@ICBM - No need to apologise mate, I got it with the amp :-) 

Do you have any recommendations?

martinw

Both or either. I've added Master volumes and fitted Power Scaling to many amps.

It depends on the amp. Some need only a master volume (either pre phase-inverter or post) because their primary tone influencing area is the preamp (or preamp and PI), and they sound fundamentally good without having to add output stage compression and drive.

Others (such as many small single-ended amps and the simpler '18W' style amps) generate their 'tone' in the output stage, or a combination of all the different stages. These of course benefit from Power Scaling, or a post PI master, or both.

Power Scaling is useful as the main volume control on simpler amps, or as a 'bulk' volume reducer in larger amps, used in combination in both cases with 'drive compensation'.

At £250 for a typical installation in a fixed bias amp, and £150 for cathode biased, I think PS is good value when compared with any decent attenuator, and I personally think it sounds better.

Edit: oh, and not all PS/VVR installations are equal.

thisisguitar

Thanks @martinw, your name was mentioned by @gjonesy as someone to ask the opinion of. 

I have just bought a Cornell 45/50, and it sounds amazing when it's really cranked, but obviously the volume is very loud. I haven't got chance to gig it until the summer, just don't want to turn up and find the sound engineers can't deal with the volume! I'm talking about 15w mode btw!

ICBM

thisisguitar said:

Do you have any recommendations?

What amp is it? That makes a drastic difference.

thisisguitar

@ICBM - Cornell 45/50 Plexi amp head

ICBM

thisisguitar said:

@ICBM - Cornell 45/50 Plexi amp head

Marshall Powerbrake.

ToneControl

I bought all sorts of passive attenuators.
I thought the Marshall powerbrake was not as good as the THD ones
But even those ruined the tone I felt
power scaling is a bit better I think

What is your purpose in reducing volume? quieter gigs, practice or recording? the answer will determine the best solution
if it's gigging, a good attenuator or power scaling will do

thisisguitar

Thanks @ICBM - I'll see if I can borrow one to try out :-)

thisisguitar

@ToneControl - To be honest, it sounds so good I'd like to use it for anything and everything. It would be nice to use it at home without earplugs, put it that way.

ICBM

ToneControl said:

I bought all sorts of passive attenuators.
I thought the Marshall powerbrake was not as good as the THD ones

Depends on the amp. For Fender BF/SF and Mesa-type amps, the Hotplate was definitely better than the Powerbrake. For Marshalls the Powerbrake was better - the Hotplate overstressed the valves on some too. For some, neither sounded good and the Airbrake sounded best...

ToneControl said:

power scaling is a bit better I think

I've preferred (the right) attenuator to power scaling, with any of the amps I've tried with power scaling - including fitting a couple - but it may also depend to some extent on the amp, as well as personal taste.

I found the power scaling tended to sound too 'controlled' whereas the attenuator tends to make the amp sound more 'heavily-driven', if that makes sense.

thisisguitar

I might just start collecting various plexi-style amps for different needs… Cornell 18/20, a Cornell 7, and my beloved 1w custom offset :-)

ToneControl

thisisguitar said:

I might just start collecting various plexi-style amps for different needs… Cornell 18/20, a Cornell 7, and my beloved 1w custom offset :-)

sounds like the path I took. Went through a phase of many many amps at once which was hard to explain to laymen

Where I ended up is with a few 30w-50w amps and an axefx2

For home use, I think the AF2 and kemper sound better than the 7w and 1w options. You still need a power amp and monitors though, so it's a different outlook, hence the query about recording, for which AF2 and KPA are a very attractive option 

thisisguitar

I actually have a pair of Genelec 8030a's which might sound good with a Kemper actually. 

My 1w is actually my favourite amp at the moment, though that might change when I get properly into the new amps. I'm lucky in that at home, I can play at gig volume in the evenings and on weekends for at least the next year.

Nerine

How about the Bad Cat Unleash?

Fortheloveofguitar

Nerine;475040" said:

How about the Bad Cat Unleash?

I looked at one of these. Riddled with issues from most of the reviews I read

ICBM

Fortheloveofguitar said:

Nerine said:

How about the Bad Cat Unleash?

I looked at one of these. Riddled with issues from most of the reviews I read

It's also a re-amp system, not an attenuator. (To be fair Bad Cat do say so, unlike the "Ultimate Attenuator".) While they can do some of the same job in some situations they are not the same thing, and it's bad marketing to try to confuse the two in my opinion.

fastboy

I've had the following attenuators:

Marshall power brake

Ultimate Attenuator (with two foot switchable volumes)

Rivera Rockcrusher

The Rivera was by far the best tonally however it had one problem. At minimum attenuation it wasn't quite loud enough to compete with a loud band without being miced up as at a guess it was dropping at least 15db's off the volume maybe more, it was close but had no headroom to boost up for solos. I was using a Laney GH 100 TI at the time in a Sabbath tribute band and this was with the master on about 9 !!!

Of course if you're in a miced scenario, no issues there but I wasn't always so it had to go as we did plenty of unmiced pub gigs as well as proper venues. The Marshall was a closish second but the Rivera was really bang on the money tonally speaking. 

As already stated, avoid the ultimate attenuator it sounds naff!