diy marshall JCM800 info in here

[okgb]

http://www.tone-lizard.com/Ultimate_JCM800.htm

The tone lizard fellow lives here in Winnipeg , a grp of us would go for
lunch on saturdays with Gar Gillies who started Garnett amps ,
[ i'll tell you about him sometime , good soul , he's passed away now ]

anyway i played a 2-12 800 combo of his and it did indeed sound nice ,
not magical and didn't cash cheques but i would've bought it , if he sold it

regards Greg

 

[12afael]

I´ve noticed that in some marshalls the masters volume does not reduce the volume absolutely and in positions near of 0 the amp has a lack of low end, somebody has some explanation for this phenomenon or has idea of how fixing it?

 

[pucho812]

[quote author="kiira"]Pucho that is one seriousely rockin kitty with his tube screamer and destroyer yeah. :razz:


I like the ideas this guy has.

http://www.tone-lizard.com/Ultimate_JCM800.htm[/quote]

I prefer the old skool big muff instead of the tube screamer but to each his own and more over yeah that kitty rocks. :thumb:

THe tone lizzard ideas look interesting... I have to read over that now I got my ******* bridged mono **** worked out... :thumb:

 

[Bryson]

[quote author="CJ"]who listens to Marshalls nowdays?
[/quote]
I still have two '70 Super Tremolo 100's.

 

[plexi]

I am a total Marshall nut.....sorry, I can't help myself. 69 small box plexi, 70 100W metal panel w/ Partridge output, 71 200W Major, 74 50W, 76 100W jmp masterVol, 81 JCM800 MV.....oh yeah and a 72 PA20. Only 3 cabs though, 69 metal handle basketweave, 72 grey check, both straight...74 slant cab all w/ greenbacks 25W.

The plexi and the 72 straight cab get used at the clubs all the time. My "portable" rig for weekend jobs are 2 brown deluxes with Tone tubby ceramics (just ok) and a Jekyll and Hyde pedal, comes close to the marshall sound but w/o the beef of a 4-12.

Brown deluxe, the best Fender amp to ever sound like a Marshall.

 

[Kit]

nd in positions near of 0 the amp has a lack of low end, somebody has some explanation for this phenomenon or has idea of how fixing it?

Check for a treble bleed cap across the pot. If that is the case, just snip it off or if you have the patience....................unsolder it.

I own a 75´50W (1987) head. It doesnt like my tele but its a good fit with my girly guitar(strat).

 

[Junction]

It doesnt like my tele but its a good fit with my girly guitar(strat).

If a strat's a girly guitar what does that make a tele? ... a pussy's?

 

[kiira]

[quote author="Kit"]I own a 75´50W (1987) head. It doesnt like my tele but its a good fit with my girly guitar(strat).[/quote]

I bet more women play strats than any other guitar. They fit in the curves real well and don't bang on your hipbone like Les Pauls and Teles. Jag* are pretty good at that too, but not as agood a guitar as a strat.

Kiira

 

[Kit]

They fit in the curves real well

Yes, I love the way it accentuate my hip.

eh....



But really, it is a comfortable guitar.

 

[12afael]

I´ve noticed that in some marshalls the masters volume does not reduce the volume absolutely and in positions near of 0 the amp has a lack of low end, somebody has some explanation for this phenomenon or has idea of how fixing it?

poor filters... two stages filter rule..
they didn`t know that rule in the time of the jcm800 or some inexperienced engineer design the 2210.

 

[mattmartin831]

Hi I am planning to build a 50W DIY JCM800 2204 within a rackmount chassis and I am wondering if anyone knows if the mounting position of the output transformer is particularly important. In order to save space and fit the transformer sideways into the 2U chassis I have, I was thinking about screwing it into the side wall and resting it on an insulated rubber-like padding. Would this negatively affect the sound or lifespan of the amp? If so I will find another solution or perhaps buy a larger chassis

 

[andyfromdenver]

Hi I am planning to build a 50W DIY JCM800 2204 within a rackmount chassis and I am wondering if anyone knows if the mounting position of the output transformer is particularly important. In order to save space and fit the transformer sideways into the 2U chassisI have, I was thinking about screwing it into the side wall and resting it on an insulated rubber-like padding. Would this negatively affect the sound or lifespan of the amp? If so I will find another solution or perhaps buy a larger chassis

It won't hurt it to be on the side wall with some type of "pad" between the casing/laminations and any metal.  However, search transformer orientation "headphone trick"  it should pop up the ax84 site.
Push Pull amps have a hum cancelling advantage, but you still need to correctly orient the OT in regards to the PT, so there is little....(tsk tsk) scratch that....NO hum  ;D
what a cool project. best wishes

*As an aside,  I have a "modded for single coils" 2204 with a add-on 2 tube reverb, it's soooo good.
Took my amp guru friend's magic touches  ;D and an add-on reverb module from Clark Amps

 

[mattmartin831]

It won't hurt it to be on the side wall with some type of "pad" between the casing/laminations and any metal.  However, search transformer orientation "headphone trick"  it should pop up the ax84 site.
Push Pull amps have a hum cancelling advantage, but you still need to correctly orient the OT in regards to the PT, so there is little....(tsk tsk) scratch that....NO hum  ;D
what a cool project. best wishes

*As an aside,  I have a "modded for single coils" 2204 with a add-on 2 tube reverb, it's soooo good.
Took my amp guru friend's magic touches  ;D and an add-on reverb module from Clark Amps

Thanks for the info. I will be using a custom toroidal power transformer made by Begis Electronics, who I found in a White Market thread on this forum. As I understand, toroidal power transformers are less prone to causing hum in an amplifier, would it still be necessary to orient the two transformer in a specific way relative to each other?

 

[andyfromdenver]

Thanks for the info. I will be using a custom toroidal power transformer made by Begis Electronics, who I found in a White Market thread on this forum. As I understand, toroidal power transformers are less prone to causing hum in an amplifier, would it still be necessary to orient the two transformer in a specific way relative to each other?

I think it would be very worthwhile. The layout stage is the one chance (before a major rehaul) to get everything right.

At your own risk!  if you can power your Pt safely, and ensure all the secondarys etc aren't exposed, put some headphones on the secondary of the OT, with the primary leads isolated etc. 
Start with the OT close to the PT, and move it around your layout, find the zero noise spot.

rig a cliff or switchcraft jack for easy headphone hook up.

In my experience, esp with a high gain amp, getting the transformer orientation right, thoughtful lead dress, and really careful heaters around the sensitive pre signal are major steps towards building the ultimate amp. 

 

[CJ]

worry more about what the OPT radiates rather than absorbs,  if you have 750 volts of 1 K Hz AC floating around 12AX7a grids, then you may have problems,

also, the type of OPT you use will make a difference as related to how stable the amp is, 

a lot of  Marshall's have the pwr xfmr and OPT on opposite ends of the chassis as you probably know by now,