Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Please login or register.

Login with username, password and session length
Advanced search  

News:

SSGuitar has been upgraded to SMF v2.0.14 and PHP7!

collapse
Pages: [1]   Go Down

Author Topic: Add a tube preamp on Randall RG100G3 Plus  (Read 270 times)

zadmight

  • SSGuitar Apprentice
  • **
  • Chip Points: 0
  • Posts: 5
    • View Profile
Add a tube preamp on Randall RG100G3 Plus
« on: August 17, 2017, 09:15:44 AM »

Hi all,
I got a Randall Rg100G3 Plus for free and I want to try to modify the sound of this amp.  I want to add a Ecc83 preamp tube. I got the schematic from Randall and I thought to "cut and paste" a parte of the preamp circuit...

I'm still completing the soldering and do the test in a few days. What do you think about this idea? Everyone tried this before?

Thanks for your suggestions  :)
Logged

J M Fahey

  • SSGuitar Global Mod
  • Legendary
  • ****
  • Chip Points: 422
  • Posts: 4086
    • View Profile
Re: Add a tube preamp on Randall RG100G3 Plus
« Reply #1 on: September 10, 2017, 11:18:11 PM »

Dunno, you tell us  :tu:
Logged

zadmight

  • SSGuitar Apprentice
  • **
  • Chip Points: 0
  • Posts: 5
    • View Profile
Re: Add a tube preamp on Randall RG100G3 Plus
« Reply #2 on: September 11, 2017, 03:52:03 AM »

I did it but the result wasn't what I expected  :( ... the sound is still pretty "cold"

I roll back and then start building a Guitar Tube Pedal... Hope to get some more warm sound this way
Logged

g1

  • Legendary
  • ******
  • Chip Points: 55
  • Posts: 431
    • View Profile
Re: Add a tube preamp on Randall RG100G3 Plus
« Reply #3 on: September 11, 2017, 12:13:41 PM »

The tube in the drawing runs off a 375V supply.
Is that what you are running it at?
« Last Edit: September 12, 2017, 02:04:34 PM by g1 »
Logged

J M Fahey

  • SSGuitar Global Mod
  • Legendary
  • ****
  • Chip Points: 422
  • Posts: 4086
    • View Profile
Re: Add a tube preamp on Randall RG100G3 Plus
« Reply #4 on: September 12, 2017, 05:06:46 AM »

I did it but the result wasn't what I expected  :( ... the sound is still pretty "cold"

I roll back and then start building a Guitar Tube Pedal... Hope to get some more warm sound this way
Ouch !!!   :(
Thanks for experimenting and taking your time to share  :dbtu:
Problem is (IF thatīs a problem) that Randalls are designed for that Pantera like brutal sound, quite the opposite of "warm",  so modding just one section will help somewhat but not fully.

Our friend Phatt has experimented a lot on getting good warm and punchy sound out of SS amps, his main point being a clever tweaking of bandwidth and frequency response to keep warmth and lose harshness, so take your time to search and read his posts, and listen to some samples uploaded here, it is very much worth it.

KMG has also uploaded killer JCM800 emulations, also search and listen at them.

Maybe you should try some of those projects, and keep your Randall as a power amp and speakers platform to amplify them, bypassing its own preamp.
Logged
Pages: [1]   Go Up
 

* User Controls
 
 
Welcome, Guest. Please login or register.
Did you miss your activation email?
* Recent Posts
LM 3886 current feedback poweramp by tarahall
[Today at 07:37:00 AM]


EBay TDA2050 boards by tarahall
[September 19, 2017, 08:39:21 PM]


Need help with ROG: fetzer valve (gain stage) + buffer by tpb03
[September 19, 2017, 02:03:31 AM]


fender bassbreaker 45 by J M Fahey
[September 16, 2017, 03:27:00 PM]


Vintage Roland Cube-60 Reverb by Jazz P Bass
[September 15, 2017, 10:53:49 PM]

* Sponsors