JTM45 reissue, a few questions.

zepp76

Thank you for the advice, I am being a bit impatient I know. Something good is bound to pop up soon, I'm just surprised no one on here has one or they are that good they don't want to sell haha!

Bygone_Tones

If you are looking to keep the volume down why are you looking for a 4x12 cab to go with it? 4x12s, and 2x12s are loud. 

Go for a single speaker with decent power handling (ideally twice the amp) in a 1x12 and I promise it will be a lot quieter for home use than a 4x12 and will allow you to drive the amp that bit more. 

zepp76

@Bygone_Tones  Sorry I should have stated that it will also be used at dedicated music/rehearsal rooms where it'll be competing against friends with 50 and100w amps. I hope to also use it at gigs in the future so a 2x12 or 4x12 would be perfect. I'm not looking to strangle the amp with attenuation just taming it a little would be ideal at home. I already have an Orange 2x12 but have read that the JTM doesn't like V30's for some reason but it likes Green backs so that's what I'm looking to get. Thank you for your advice though.

MtB

As a possible sub-thread, what is the forum wisdom on how close a clone would get to the real thing sounds / tone wise?

I've built five amps from kits or established schematics / layouts, and I'm thinking that a JTM from someone like Modulus / TAD (may be too expensive) or WeberVST might be my next project.

I know, and accept that the resale value won't be the same, but I won't be building it with that in mind.

Is there particular mojo in the components that Marshall use - due to the maker or spec of transformers, for example?   

zepp76

@ICBM  Sorry to bother you again but could you give me an opinion on this please: 

https://www.gumtree.com/p/guitar-instrument/marshall-jtm45-2245-ri-classic-guitar-amp-head-ppimv-master-volume-other-upgrades-/1212074839

He says it has a new solid state rectifier, now I'm not up on my electronics so was wondering what that does in connection to the rectifier valve? Once again thank you for any help you can give.

ICBM

zepp76 said:

@ICBM  Sorry to bother you again but could you give me an opinion on this please: 

He says it has a new solid state rectifier, now I'm not up on my electronics so was wondering what that does in connection to the rectifier valve? Once again thank you for any help you can give.

Need to see inside - those pics tell you nothing really, other that it's in good cosmetic condition and hasn't been drilled.

A solid-state rectifier could be a simple plug-in unit that replaces the valve - which is ideal, and can easily be put back to a valve if you want - or a bodge inside involving soldering diodes across the socket, or other unnecessary modding. (Some techs do this.)

I would want to see how the PPIMV has been done too - fitting it in that position isn't good practice because it means leading the cabling back across past the preamp, which can cause instability. The best place is in the second speaker jack hole.

zepp76

So the PPIMV would seem to be done by someone who may not know what they're doing, hmm that's a bit of a put off. I'll email him and ask if he can do a gut shot and see where we go from there.

zepp76

This is the picture the seller sent me not sure if it helps?

https://i.imgur.com/akmctpx.jpg

Voxman

zepp76 said:

@ICBM ok possibly the last question if you don't mind, why do some people connect two of the channels with a patch lead? I see some people do it and some don't. Is there any benefit to doing it? Thank you for all your help so far you've been very helpful and have helped me make up my mind as to wether or not to get one.

I used to do this when I had a JTM45 - it adds more hair (grit/distortion) and volume, but also helps distort the amp a little more at lower volumes too.  The JTM45 is a 2-channel amp - you don't 'switch' channels in the conventional sense but each channel has its own input jack (well, actually 2).  The normal channel is darker and the treble channel is brighter.  Jumping across the channels partly mixes both channels together but it also gives you a gain boost because of how the inputs are wired (I think these are in parallel from memory).    

ICBM

zepp76 said:

This is the picture the seller sent me not sure if it helps?

It helps with Part 1 - that's a proper solid-state rectifier plug-in on the right, so no worry about that.

Part 2 needs looking inside the chassis and he may not be willing to do that, but the worst case scenario is that it needs a small amount of work to move the MV control. It is possible it's fine anyway, if he's used decent shielded cable and routed it properly.

At £650 I'd take the chance, if you're keen .

As Voxman said, jumping the channels gives you a small gain boost and the ability to get a fuller tone by blending in Channel 2, which is usually too dark and muddy to use on its own. You can still do that with this, since there's one input left on that channel.

zepp76

The seller has his own website and seems to know what he's doing https://amplifiedlondon.wordpress.com/

i think i might just take a punt at that price, I just hope it doesn't sell today as I'm in hospital having a liver biopsy!

TimmyO

zepp76 said:

The seller has his own website and seems to know what he's doing https://amplifiedlondon.wordpress.com/

i think i might just take a punt at that price, I just hope it doesn't sell today as I'm in hospital having a liver biopsy!

Priorities man, livers are over rated!

(Also, all the best for the procedure) 

zepp76

TimmyO said:

zepp76 said:

The seller has his own website and seems to know what he's doing https://amplifiedlondon.wordpress.com/

i think i might just take a punt at that price, I just hope it doesn't sell today as I'm in hospital having a liver biopsy!

Priorities man, livers are over rated!

(Also, all the best for the procedure) 

The biopsy went well thanks. The more I look at that amp for sale the more I feel like I'd rather buy a totally original one, completely unmolested. At least then if I want work doing to it I will know who's done it. I don't know, I need to have a long hard think.

photek

MtB said:

As a possible sub-thread, what is the forum wisdom on how close a clone would get to the real thing sounds / tone wise?

I've built five amps from kits or established schematics / layouts, and I'm thinking that a JTM from someone like Modulus / TAD (may be too expensive) or WeberVST might be my next project.

I know, and accept that the resale value won't be the same, but I won't be building it with that in mind.

Is there particular mojo in the components that Marshall use - due to the maker or spec of transformers, for example?   

I much prefer the hand wired clones I have had to the stock reissue Marshall ones. I had an ampmaker (I think that was the name) one with KT66's that was really open sounding and my current Ceriatone (thanks @John_A) one is really punchy and has loads of headroom with 6L6's, infact it barely breaks up until its at 8/9 out of 10.

I prefer mine with the channels jumpered, dial the bright channel up to the required volume then add a bit of the normal channel in to fatten it up. The other benefit of a clone is you can get them in a small box head so they actually fit the 2061 cab.

http://i23.photobucket.com/albums/b371/Markcupra/ACFD5F84-74DB-4311-8D48-2DFD753B8235_zpseykjuvy5.jpg

MrBump

Sounds incredible.  Does anyone do similar as a 2x12 combo?

MtB

The Marshall 1962 Bluesbreaker

https://marshallamps.com/products/amplifiers/vintage-re-issues/1962-bluesbreaker/

photek

MrBump said:

Sounds incredible.  Does anyone do similar as a 2x12 combo?

Bluesbreaker would be the closest thing chap.

MtB

@photek - do you mean the 36w Ampmaker head? That uses 4 EL84s 

MrBump

photek said:

MrBump said:

Sounds incredible.  Does anyone do similar as a 2x12 combo?

Bluesbreaker would be the closest thing chap.

Yeah, you'd think so on paper.  Thing is, I've not liked many of the clips of the Bluesbreaker, whereas the JTM45 - it's hard to find a bad sounding clip...

Voxman

photek said:

MrBump said:

Sounds incredible.  Does anyone do similar as a 2x12 combo?

Bluesbreaker would be the closest thing chap.

The Marshall 'Bluesbreaker', as made famous by Eric Clapton (so named by Marshall because he used it whilst with John Mayall's 'Bluesbreakers' in the mid '60's), is essentially a JTM45 in a 2x12" combo (2 x 25w Celestion Greenbacks).  Not cheap - new price around £1300 or circa £2300 for a Handwired version!   Used prices expect to pay upwards of £800.  Cheapest on EBay currently is £925;

http://www.ebay.co.uk/itm/Marshall-JTM-Bluesbreaker-Guitar-Amplifier-/232207884427?hash=item3610ab208b:g:7-oAAOSwLEtYfIqR