Search found 55 matches

by Tube2stomp
10 Oct 2018, 09:28
Forum: Amplifiers
Topic: Marshall JMP-1 Preamp mods?
Replies: 97
Views: 80252

Re: Marshall JMP-1 Preamp mods?

Added VB1a to the OD channel :secret:
Still needs tweaking but happy times indeed :thumbsup

Current signal path is:
IC34a > Gain Control > IC19a > IC19b > VB1a > VB2a > VB2b > IC12c > IC18a
by Tube2stomp
21 Sep 2018, 20:51
Forum: Amplifiers
Topic: Marshall JMP-1 Preamp mods?
Replies: 97
Views: 80252

Re: Marshall JMP-1 Preamp mods?

Changed all resistors of the Marshall side preset tone stack to pots. Getting much better sounds. Will see over time if I'll settle on a one setting, if so, I'll preset it. p.s. if you'll do as I did and remove IC12a completely, change C86 to lower value (22n is a classic) AND a must is to add a gri...
by Tube2stomp
21 Sep 2018, 16:30
Forum: Amplifiers
Topic: Marshall JMP-1 pre tube voltages
Replies: 5
Views: 5569

Re: Marshall JMP-1 pre tube voltages

Mine reads 150VDC
Its weird cause it is a 115/230 machine and our local net is 235VAC.
What worries me is that heaters are at 11VDC, which is lower from what the schematic shows (12VDC unregulated, which by it self is on the low side).
by Tube2stomp
16 Sep 2018, 15:34
Forum: Amplifiers
Topic: Marshall JMP-1 Preamp mods?
Replies: 97
Views: 80252

Re: Marshall JMP-1 Preamp mods?

I'm at work so will give the headlines of what I have so far, all done as I was reading this thread: Took D12 out, with it the whole bridge rectifier. Adding diode clipping with a pedal is something else... it's my choice... I'm not married to it all the time. So diodes out = good. Kept reading... W...
by Tube2stomp
16 Sep 2018, 13:04
Forum: Amplifiers
Topic: Marshall JMP-1 Preamp mods?
Replies: 97
Views: 80252

Re: Marshall JMP-1 Preamp mods?

Well, guess I'm late by, what, 25 years? to the JMP-1 party. Just got my first one :applause: And ah.... yea... not what I expected... on its own it sounds like a solid state pedal :hmmm: If I had it 25 years ago I would've probably been super happy youngster metal guitar player playing with distort...
by Tube2stomp
04 Mar 2016, 15:14
Forum: Pimp-My-Cheap-Pedal
Topic: Ibanez DE-7 mods thread
Replies: 28
Views: 22270

Re: Ibanez DE-7 mods thread

Thanks a lot for the detailed mods!!! Where did you cut the signal to insert a repeats external loop (send/return)? is it simply a wire in/out to the stereo jack or did you add some resistance/caps or something? Do you have any tip on how and where is best to make a lows/bass rolloff mod? this is a ...
by Tube2stomp
01 Jul 2010, 22:09
Forum: Amplifiers
Topic: tube amp without power transformer.... is it possible?
Replies: 12
Views: 4374

Re: tube amp without power transformer.... is it possible?

"... I see dead people..." :lol: Since you don't seem to be very experienced with tube amps, here is another life saving tip free of "charge" (pun intended): When working on a live tube amp, ALWAYS KEEP ONE HAND IN YOUR POCKET (or behinde your back)!!! Never ever put one hand ins...
by Tube2stomp
01 Jul 2010, 21:22
Forum: Amplifiers
Topic: PEavey Deuce | in half?
Replies: 10
Views: 5129

Re: PEavey Deuce | in half?

Sorry mate, but half power won't give you any percived output change. And by pulling two tubes you'll change the amp's sound for sure. Just to give you a measure, you'll need one tenth the power to get a real - in your ears - half volume :blackeye In your case we're talking about 12W output... which...
by Tube2stomp
01 Jul 2010, 20:50
Forum: Amplifiers
Topic: Free download Vacuum Tube Design Book
Replies: 16
Views: 8099

Re: Free download Vacuum Tube Design Book

Simply amazing!
Thanks :)
by Tube2stomp
29 Apr 2010, 13:52
Forum: Modern Stompbox Effects (1975 - ...)
Topic: TC Electronics - Chorus/Flanger [schematic]
Replies: 12
Views: 5843

Re: TC electronic CHORUS/FLANGER [schematic]

The link here is not working any more, but I remember seeing the pics before and yup, it's a complex little mofo :slap: Anyone has a "lite" version schematic for this thing? I'm sure this pedal packs many extra sub circuits that can be shaved off (by someone who understands them of course)...
by Tube2stomp
29 Apr 2010, 13:19
Forum: Boutique Stompboxes dissected...
Topic: Xotic EP-Booster [traced]
Replies: 170
Views: 90209

Re: Xotic EP-Booster [traced]

[smilie=a_hrm.gif] Do you guys use load lines to see how SS gain devices behaves? I draw them for circuits floating around to try and learn what's going on... and many times I end up like this >>> :shock: :scratch: [smilie=a_hrm.gif] What also I don't understand is that (at least) jfets are not very...
by Tube2stomp
26 Apr 2010, 15:37
Forum: Boutique Stompboxes dissected...
Topic: Suhr Riot [gut shot]
Replies: 51
Views: 12158

Re: Suhr Riot [gut shot]

Grendahl mate, someone wrote that Suhr's employee wrote @TGP and you wrote that it appears to be him. As a long time member there, I just wanted to confirm that it was him and not someone writing "in his name" :thumbsup He also writes in HRI (I don't read there any more), and I also bumped...
by Tube2stomp
26 Apr 2010, 11:55
Forum: Software Room
Topic: Miscellaneous electronic calculations - software
Replies: 8
Views: 4303

Re: Miscellaneous electronic calculations - software

DAMN!
Impresive piece of code :applause:

*Thank you feedback to author sent!
by Tube2stomp
25 Apr 2010, 13:45
Forum: Boutique Stompboxes dissected...
Topic: Cornish G2 - Guts, Schematic, Layout (from Tracer's Fund) [traced]
Replies: 240
Views: 121643

Re: Cornish G2 - Guts, Schematic, Layout (from Tracer's Fund) [traced]

Sound wise I never had any interest in any Cornish pedal, let alone a BM. But still you guys deserve respect and thumbs up for the effort, so in the words J. Peterman: "Kudos, Elaine, on a job... done." :lol: Btw, bootstrapping the input impedance does work, but it depends a lot on the fee...
by Tube2stomp
25 Apr 2010, 13:17
Forum: Boutique Stompboxes dissected...
Topic: Suhr Riot [gut shot]
Replies: 51
Views: 12158

Re: Suhr Riot [gut shot]

Husky = JS Btw, checking pedals on an OD100 is like hearing that Elle MacPherson's husband met her on a blind date :mrgreen: Sure, who wouldn't go on a blind date with her, but that doesn't say anything about blind dates... does it? :lol: A friend has an OD100 and by far it is one of the best amps I...
by Tube2stomp
16 Apr 2010, 11:39
Forum: Software Room
Topic: Orcad Libraries????
Replies: 2
Views: 2182

Re: Orcad Libraries????

Hey Mike,

Just got into Spice my self :blackeye
Did you find any good libraries since "Sat Jul 12, 2008 10:19 am"? :mrgreen:

Cheers mate
by Tube2stomp
13 Apr 2010, 15:12
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 13074

Re: Fet version of the JCM800

I think I see where the issue (for me) is. Some things in the jibrish translations of this article and from Viktor Kempf(?) talked about the internal resistance of the fet vs tubes with respect to the loads (where triodes need a higher load then their internal resistance, and fets are... basically k...
by Tube2stomp
12 Apr 2010, 22:09
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 13074

Re: Fet version of the JCM800

Yea I saw that the fet needs to have some specific parameters, but why the *positive* bias of the gate/grid? They put the fet at saturation from the begining which brings up three questions un answerd: 1. why when you positive bias a fet (saturation, above the source) it soft clips the signal just l...
by Tube2stomp
12 Apr 2010, 14:44
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 13074

Re: Fet version of the JCM800

KMG, I checked the links you gave (thru yahoo babelfish)... man, to read tech documents translated from Russian into half jibrish English by a Hebrew speaker who is not too familiar with solid state is quite an IQ test to say the least :blackeye Anyway, I understand what you guys try to accomplish a...
by Tube2stomp
21 Feb 2010, 13:11
Forum: Amplifiers
Topic: Blonder-Tongue - Audio Baton (All-tube Graphic-EQ)
Replies: 20
Views: 7346

Re: Blonder-Tongue - Audio Baton (All-tube Graphic-EQ)

Thanks Borislav, this one is more readable.
And yes, MMF simply means pF.
Btw, this schematic is not exactly like the non negative one even though they both are marked as version 3.3
Wonder why...

Thanks mate :)