My Marshall JMP 1987 clone. Sound clip. The Unchained Riff (of course).

[Aquila Rossa]

Just a quick sample of the amp's tone. It's very loud, so it's overloading my phone's mic a tad. It's good enough to hear what the amp does though.

It's my nephew Caleb playing the guitar after I had quickly dialed up a tone. Not too bad for our first attempt after slightly modding the amp to a different Plexi spec. All the overdrive is coming from the amp, i.e, no drive or boost pedals used. The Les Paul has a Super Distortion in the bridge position, which is what's being used here. A touch of compression and reverb is added in post. I can't remember the amp settings, but the volume of the treble channel was set to at least 8, so it was overdriving very hard and punchy. None of that flowery edge of break up stuff in these parts (unless it's a Strat and SRV etc).

[Aquila Rossa]

P.S. Caleb has been around guitars all his life. His dad was in a NZ metal band called Confessor that supported Megadeth and Motorhead etc. He's getting quite good, but is busy finishing his jewelry making apprenticeship right now. I have almost convinced him to get in a band. He'll wanna use my amp though.

[dayl]

That sounds killa

[Aquila Rossa]

That sounds killa

Cheers. A guy over the north shore built it. I can not remember his name. He builds lots of Marshall style amps. He said the amp was going for the Live At The Apollo tone. AC/DC I presume, because it sounded like Malcolm's JTM45 to me, with a bit of Angus' Plexi mixed in. He did not seem to like selling it (I was the only bidder, so he only got his reserve price). He also did not like the idea of me 'tinkering' with it after I bought it.

It only took three or four component changes for me to get it sounding like this. But getting those components required freaking international shipping (the 0.68uF cap, because i didn't want to bother the fella on here who offered me one of his spares).

I get kind of nervous running it this hard though. I saw the Rig Rundown show how many spare amps Angus takes on tour, plus how he employs a full time repair tech to keep them going, i.e, they blow up. She'll be right I guess (sometimes I think about making it into a 2204 to tame it a tad, or running it on a variac for the same reason).

[Reg18]

Sounds great! Wanna go play this riff now.

[FuzzMonkey]

You're speaking my language with that tone. Sounds great!

[Aquila Rossa]

You're speaking my language with that tone. Sounds great!

Cheers. It's getting there. It's partly down to how the lad is playing the riff. He's got the thing we need to sound good. The thing some players just have and others like me have to work hard to get. Lucky him.

I am thinking of ordering one of the new Mr Scary Lynch Mod V2 things. Not for the extra gain. The amp has plenty of gain. For more gain at lower levels and for what that gadget does to the tone and feel of the amp. I like how there's no need to drill and extra tube socket etc. How it can be easily removed too. If I get it from that Duncan fella in the south Island, I can Afterpay it, so its cost hurts over 8 weeks instead of all at once

Another thing on the list is to get a 4x12, but that costs heaps.

rxm1plurpqzxso7nldj0.jpg (75.58 KiB) Viewed 566 times

[FuzzMonkey]

You're speaking my language with that tone. Sounds great!

Cheers. It's getting there. It's partly down to how the lad is playing the riff. He's got the thing we need to sound good. The thing some players just have and others like me have to work hard to get. Lucky him.

I am thinking of ordering one of the new Mr Scary Lynch Mod V2 things. Not for the extra gain. The amp has plenty of gain. For more gain at lower levels and for what that gadget does to the tone and feel of the amp. I like how there's no need to drill and extra tube socket etc. How it can be easily removed too. If I get it from that Duncan fella in the south Island, I can Afterpay it, so its cost hurts over 8 weeks instead of all at once

Another thing on the list is to get a 4x12, but that costs heaps.


rxm1plurpqzxso7nldj0.jpg

There is one one Trade Me at the moment:

https://www.trademe.co.nz/a/marketplace ... 4610749935

Might be a V1 maybe??? Not sure now the price compares to a new one etc.

Does the amp have a master volume? PPIMV?

[Aquila Rossa]

You're speaking my language with that tone. Sounds great!

Cheers. It's getting there. It's partly down to how the lad is playing the riff. He's got the thing we need to sound good. The thing some players just have and others like me have to work hard to get. Lucky him.

I am thinking of ordering one of the new Mr Scary Lynch Mod V2 things. Not for the extra gain. The amp has plenty of gain. For more gain at lower levels and for what that gadget does to the tone and feel of the amp. I like how there's no need to drill and extra tube socket etc. How it can be easily removed too. If I get it from that Duncan fella in the south Island, I can Afterpay it, so its cost hurts over 8 weeks instead of all at once

Another thing on the list is to get a 4x12, but that costs heaps.


rxm1plurpqzxso7nldj0.jpg

There is one one Trade Me at the moment:

https://www.trademe.co.nz/a/marketplace ... 4610749935

Might be a V1 maybe??? Not sure now the price compares to a new one etc.

Does the amp have a master volume? PPIMV?

No master volume. Partly because I have the Power Station, but partly because I am not sure if I want a master volume, or if I do; what type. There's several, each with their pros and cons. All of them change the sound of the amp, but then again so does the Power Station.

Another option is power scaling. That lowers volume too, but all the tubes can still clip and saturate like the amp is running at full voltage. I think those Marshall Studio amps are using it to get just 5-20 watts out of a pair of EL34s. I bet they did not pay the fee to the fella that says he owns rights to the mod (London Power in Canada)

The Lynch mod on TM is an earlier Hot Mod V2 they did. Cool fun, but pretty gnarly is the word on them, i.e., over the top gain. The newer Mr Scary one is less gain, because there's a 12AT7 instead of a 12AX7 as one of the tubes. Sounded good in demos. I am wary of demos enticing me to buy stuff, but they do. Entice me to buy stuff I mean. There's no sweeter promise than the promise of great tone.

[FuzzMonkey]

No master volume. Partly because I have the Power Station, but partly because I am not sure if I want a master volume, or if I do; what type. There's several, each with their pros and cons. All of them change the sound of the amp, but then again so does the Power Station.

Another option is power scaling. That lowers volume too, but all the tubes can still clip and saturate like the amp is running at full voltage. I think those Marshall Studio amps are using it to get just 5-20 watts out of a pair of EL34s. I bet they did not pay the fee to the fella that says he owns rights to the mod (London Power in Canada)

The Lynch mod on TM is an earlier Hot Mod V2 they did. Cool fun, but pretty gnarly is the word on them, i.e., over the top gain. The newer Mr Scary one is less gain, because there's a 12AT7 instead of a 12AX7 as one of the tubes. Sounded good in demos. I am wary of demos enticing me to buy stuff, but they do. Entice me to buy stuff I mean. There's no sweeter promise than the promise of great tone.

These vintage, Non-Master Volume amps do sound their best when just cranked without anything between the amp and the speaker cabinet.

[Aquila Rossa]

I bought a JJ 12AX7S because the short plate design is supposed to have very low microphonics and noise. Nope. The trusty old Shuguang 12AX7Bs in there are much less noisy, less microphonic, and sound nicer too. Still my favourite modern production ECC83 valve. Too bad the factory burned down. Supposed to be restarting though.

I have not tried the Psvane or the reissue Mullard ones. Tung Sol were too bright for my liking, but are decent. The JJs are bright too, but its a nasty bright. TAD just cherry pick tubes made by others and rebrand them as TAD. Same as Groove Tubes etc. That can't hurt if they really do weed out the duds etc. It makes me wonder what happens to the one that do not pass their testing? Sold cheap on eBay?

Preamp tubes do vary in sound, but you hear it more in some amps than others is what I have found.

Next thing to do with the amp is look into the slight blocking distortion I can hear. It could be the phase inverter is not working right. It could be the output tubes have strayed out of match, or the bias has strayed due to resistor drift. It could be something in the amp overloading a tad too much. I also have to finally get around to learning how to bias a fixed bias amp. I know the procedure, but have never tried it. It's not the high voltage that puts me off, it's the maths.

Another thing is how the input is very, very sensitive when the amp is turned up over half. If we say picking very softly is 1, then the amp jumps to 11 by picking ever so slightly harder. The amp prefers you just bash the strings hard out. I am not sure what makes it behaves that way. Quite typical for a Plexi though, although this one is especially so (I am thinking it might actually be the 60 watt 2x12 that makes that happen, because it doe snot happen so much when the amp is plugged into the Freyette Power Station like in the video above -- need to try a 4x12 with it, or a higher rated 2x12).

[Optical]

The Marshall studio amps dont have any of the London power scaling circuitry in them.
They just run a low plate voltage on the power tubes and a second power supply for regular voltages on the preamp.

[GrantB]

I bought a JJ 12AX7S because the short plate design is supposed to have very low microphonics and noise. Nope. The trusty old Shuguang 12AX7Bs in there are much less noisy, less microphonic, and sound nicer too. Still my favourite modern production ECC83 valve. Too bad the factory burned down. Supposed to be restarting though.

I agree - the Shuguang's have been hard to beat in any of my amps. When they were plentiful I sold a number of amps full of them...bugger

[calling card]

My JMP clone sounds like shit until about 6 is dialed into non master volume. As I understand it that it how it is with plexi breed.

[Aquila Rossa]

I bought a JJ 12AX7S because the short plate design is supposed to have very low microphonics and noise. Nope. The trusty old Shuguang 12AX7Bs in there are much less noisy, less microphonic, and sound nicer too. Still my favourite modern production ECC83 valve. Too bad the factory burned down. Supposed to be restarting though.

I agree - the Shuguang's have been hard to beat in any of my amps. When they were plentiful I sold a number of amps full of them...bugger

Ages ago I tested the Chinese ones against three vintage ECC83s and only one of the vintage ones sounded nicer to me. A Mullard, a Miniwatt, and a Brimar. Ryan tested the first two of those and they were spot on. One of them he said was perfect in every way. I would not be surprised if it was the less than perfect one that won that comparison though. Audiophile type perfection not required.