Marshall monoblock amp

[blutonium92]

Anyone ever had an experience using a Marshall valve amp for hifi?

My dad recently got a bargain on a EL34 100/100 monoblock amp, dont think hes going to keep it but i may try it out before he gets rid.

[The Grand Wazoo]

I'd be interested in your findings.
However, the question that crosses my mind is this: If guitarists value Marshall amps for the thing that they call 'tone', why might one make a useful hi-fi amp, when what we seek is fidelity to the recording?

[John]

I cannot see it working well
Marshall make great guitar amps

[Rothchild]

It might take some modding to make it work right, if you can minimise or remove the pre-amp stage then it might work. Remember, the input is going to be sensitive and very high impedance as it's optimised for a guitar signal (unless it has a line in too) and the pre-amp gain is expressly designed so that it can be over driven so if you feed it a line level signal you're going to want to keep the 'gain' right down.

Edit: Just looked this amp up, it's very much a 'straight' power amp so what've said above largely won't affect it. I'd be interested to hear how you get on, with the presence left flat and then you might stand a chance. What a beast of a box, shame about the fan.

[John]

If its a power amp it is worth a try

[Ali Tait]

As I understand it, the output transformers are deliberately made small so they are easily overdriven, which is what you want from a guitar amp. Definitely not what you want from a hi fi amp though.

[PaulStewart]

As I understand it, the output transformers are deliberately made small so they are easily overdriven, which is what you want from a guitar amp. Definitely not what you want from a hi fi amp though.

Also, on a Marshall guitar head the master volume is designed to increase distortion to get the "valve tear" not what you want for Hi-Fi :( On the other hand they did make some very good valve PA amps, is this one of them? IIRC, these were ultra linear and very clean.

[Arkless Electronics]

It could have promise..... I've worked on quite a few of these and although I've not put one on a distortion analyser the waveform looks clean on a scope. It appears to be more a "straight" stereo power amp than an effects box and the transformers are pretty large. Some modifications would probably hugely improve it for hifi use (removing "presence" circuitry and any thing else that is holding it back). At the end of the day though it's unlikely that they would pay the large extra amount it takes to get op transformers that are of really wide bandwidth so they are likely to be the limiting factor.

[Stratmangler]

The amps are designed to feed 4x12 cabinets with lots of lovely overload harmonics.
I wouldn't bother trying them as hifi amps - they'll not provide sufficient clean headroom.

[blutonium92]

Dont think ill be testing them to be fair, would be intersting but i dont have a stand alone preamp. All my amps are integrated. Do have a phono stage but dont think that would be suitable.

[Arkless Electronics]

Dont think ill be testing them to be fair, would be intersting but i dont have a stand alone preamp. All my amps are integrated. Do have a phono stage but dont think that would be suitable.

You can use your phono stage or a CD player etc straight into the Marshall as it has its own volume controls IIRC.