JCM800 mod1992 bass series

Safe haven for everything low-frequency. Bass players unite in this forum.

JCM800 mod1992 bass series

Postby soundandthecity on Thu Mar 20, 2008 6:13 pm

Hi folks,
i scored a fullstack (JCM800 mod1992 4xEL34)+(2x4x12"/400W each/mod 1984) recently for cheap. The sound is fine but it has no power in any way :? . May be that i`m pampered by the DR201-clone and the Peavey CL400, but even my Roost SR25 makes much more pressure than the Marshall does.
Is it normal that there is not so much punch in the older Marshall bass amps? (I can`t believe when i hear Lemmy :) ...)
Regards,
SATC
soundandthecity
Squire
 
Posts: 536
Joined: Wed Feb 25, 2004 8:01 am
Location: Northern Germany

Re: JCM800 mod1992 bass series

Postby joe_jr on Thu Mar 20, 2008 9:59 pm

soundandthecity wrote:Hi folks,
i scored a fullstack (JCM800 mod1992 4xEL34)+(2x4x12"/400W each/mod 1984) recently for cheap. The sound is fine but it has no power in any way :? . May be that i`m pampered by the DR201-clone and the Peavey CL400, but even my Roost SR25 makes much more pressure than the Marshall does.
Is it normal that there is not so much punch in the older Marshall bass amps? (I can`t believe when i hear Lemmy :) ...)
Regards,
SATC



Get it checked out by an amp tech, maybe it needs to be fixed. My apologies if you are an amp tech! :oops:
joe_jr
Page
 
Posts: 251
Joined: Fri Jun 15, 2001 7:01 am
Location: Detroit

Postby worldoftone on Mon Mar 24, 2008 6:06 pm

Is it normal that there is not so much punch in the older Marshall bass amps?


I would say yes. I had one for a few months, but got rid of it because it just didn't stand up to my '69 or '74 Super Basses. Not nearly the punch or crunch that I would expect. And mine was setup correctly. I was using it with a couple different cabs, and my '73 P-Bass at the time.

- WOT
The Ayatollah of uh-rock-and-uh-rollahhhhhh

Image
worldoftone
Prince
 
Posts: 3742
Joined: Fri Feb 13, 2004 8:01 am
Location: Terror Lake

Postby Happy Face on Mon Mar 24, 2008 8:01 pm

I have found that 4 EL34s don't provide enough oomph for bass. Unless you daisy chain 3 of 'em :)

But in the past, a number of people here have disagreed, especially when the EL34s are in a Hiwatt.
Happy Face
Page
 
Posts: 287
Joined: Wed Jul 19, 2006 6:42 pm
Location: Portland, Maine USA

Postby soundandthecity on Tue Mar 25, 2008 6:39 am

I do have some EL34 amps and like the sound very much. One MAQUIS, an old german brand. It pushes the EL`s very hard and you will get about 140W clean. I have a Roost SR26 /6xEL34 design, waaayyy more punch than the Marshall and a lot louder, both, the MAQUIS and the Roost. And don`t get me wrong, the sound is fantastic, but power-wise it is not what I would expect from a 4xEL34 full tube amp.
May be I have to do a 8xKT88 power amp section :twisted: for this bugger....
THX for the input,
SATC
soundandthecity
Squire
 
Posts: 536
Joined: Wed Feb 25, 2004 8:01 am
Location: Northern Germany

Postby Happy Face on Tue Mar 25, 2008 6:08 pm

soundandthecity - that's interesting. I'm a typical American - I've never even heard of those two brands!!

But when I spoke about 4xEL34 amps, I was thinking of my Klemt Echolette Mustang which I was playing last weekend. It just breaks up too soon to be useful at high volumes.
Happy Face
Page
 
Posts: 287
Joined: Wed Jul 19, 2006 6:42 pm
Location: Portland, Maine USA

Postby soundandthecity on Wed Mar 26, 2008 6:06 am

Hi Happyface,
have a lloksie here:
http://www.andy-duke.co.uk/roost/roosthistory.html
There is a lot information about Roost amps. MAQUIS amps were build in Germany in the 70/80ies by Schumann, but the old man died recently. These amps were not too popular, even in Germany. They have solid state preamps and EL34 power amps. Very clean and warm sounding and insanely loud.
Regards,
SATC
soundandthecity
Squire
 
Posts: 536
Joined: Wed Feb 25, 2004 8:01 am
Location: Northern Germany

Postby soundandthecity on Wed Mar 26, 2008 6:07 am

Hi Happyface,
have a looksie here:
http://www.andy-duke.co.uk/roost/roosthistory.html
There is a lot information about Roost amps. MAQUIS amps were build in Germany in the 70/80ies by Schumann, but the old man died recently. These amps were not too popular, even in Germany. They have solid state preamps and EL34 power amps. Very clean and warm sounding and insanely loud.
Regards,
SATC
soundandthecity
Squire
 
Posts: 536
Joined: Wed Feb 25, 2004 8:01 am
Location: Northern Germany

Postby ayh on Thu Mar 27, 2008 6:36 am

I have a Maquis.Im makin a tube preamp for it though and putting 6550s in it if they'll fit the power tube socket spacing
ayh
Motivational Speaker
 
Posts: 2578
Joined: Thu Jun 28, 2001 7:01 am
Location: TN

Postby soundandthecity on Fri Mar 28, 2008 12:17 pm

AYH,
if I ever find the schematic in one of my moving-boxes (moved from Switzerland to Germany) I`ll mail it to you. There will be space enough for mounting 6550`s but you will fry them with the nearly 800Volts... better go KT88`s. What kind of preamp you want to build in? I´d like to do a superbass in mine. With a set of proper EL34 it produces 140 Watts of clean power and up to 200Watts distorted, may be you wouldn`t need 6550`s ;-).
Best regards,
SATC
soundandthecity
Squire
 
Posts: 536
Joined: Wed Feb 25, 2004 8:01 am
Location: Northern Germany

Postby ayh on Sat Mar 29, 2008 9:34 pm

soundandthecity wrote:AYH,
if I ever find the schematic in one of my moving-boxes (moved from Switzerland to Germany) I`ll mail it to you. There will be space enough for mounting 6550`s but you will fry them with the nearly 800Volts... better go KT88`s. What kind of preamp you want to build in? I´d like to do a superbass in mine. With a set of proper EL34 it produces 140 Watts of clean power and up to 200Watts distorted, may be you wouldn`t need 6550`s ;-).
Best regards,
SATC


My brain is telling me that the new tube preamp will drop the overall plate voltage considerably....
The transformers in those look al lot like the ones in some 100w Stramps

I made a tweed bassman preamp ,the usual.But haven't been able to insatll it yet

Image
ayh
Motivational Speaker
 
Posts: 2578
Joined: Thu Jun 28, 2001 7:01 am
Location: TN

Postby ayh on Tue May 27, 2008 9:58 pm

SATC
So I got it done ,and it sounds GREAT. The Metal cover that they put over the solid state preamp made a perfect place to mount 2 tube sockets ,filter cap & terminal board

I had always intended to use it for bass .I did the bassman preamp with a 12AT7 in V1 ,12AX7 V2 and a 5751 in the phase.I stuck the 6550s in there.plate voltage still hot as Hades.
Sounds perfect like bass used to sound
May even take it on the road tomorrow ,just to shake it down
ayh
Motivational Speaker
 
Posts: 2578
Joined: Thu Jun 28, 2001 7:01 am
Location: TN

Postby ayh on Sat Jun 07, 2008 6:50 am

A phone cam pic of how I laid out the preamp.That cowling WAS perfect for it

Image
ayh
Motivational Speaker
 
Posts: 2578
Joined: Thu Jun 28, 2001 7:01 am
Location: TN

Postby worldoftone on Sun Jun 08, 2008 5:42 pm

Interesting.

- WOT
The Ayatollah of uh-rock-and-uh-rollahhhhhh

Image
worldoftone
Prince
 
Posts: 3742
Joined: Fri Feb 13, 2004 8:01 am
Location: Terror Lake

Postby soundandthecity on Mon Jun 09, 2008 5:27 am

I see a lot of space for good ideas an the turret board :twisted: . To sad that i have not enough time to work on mine....
Do you have some sound files?
Regards,
SATC
soundandthecity
Squire
 
Posts: 536
Joined: Wed Feb 25, 2004 8:01 am
Location: Northern Germany

Next

Return to Bass Talk

Who is online

Users browsing this forum: No registered users and 1 guest