Search found 285 matches

by blackbunny
18 Mar 2020, 14:29
Forum: Electric Guitar Rewiring
Topic: BC Rich booster circuit?
Replies: 2
Views: 784

Re: BC Rich booster circuit?

Here's a trace I made in 1979 of a '76 or '77 Mockingbird preamp & vari-tone. It uses an easy to find 2N5088 NPN low noise small signal transistor, and cheap greencaps. The inductor in the vari-tone was cylindrical and dipped in black resin, and had 1000 stamped on it. I assumed it was 1000mH (=...
by blackbunny
02 Apr 2018, 01:32
Forum: Pimp-My-Cheap-Pedal
Topic: Add Some High End to Tubescreamer TS-9
Replies: 5
Views: 2351

Re: Add Some High End to Tubescreamer TS-9

Sorry, my previous diagram is wrong. :oops: On this board C5 is actually the 0.22 yellow tantalum capacitor with the yellow circle. It can be replaced with a smaller value electro or a film type if you can squeeze in in there.
by blackbunny
24 Mar 2018, 05:59
Forum: Pimp-My-Cheap-Pedal
Topic: Add Some High End to Tubescreamer TS-9
Replies: 5
Views: 2351

Re: Add Some High End to Tubescreamer TS-9

Change NP electro can type capacitor C5 to a lower value to raise the corner frequency of the LP filter - lets more highs through.
by blackbunny
21 Mar 2018, 23:30
Forum: Pimp-My-Cheap-Pedal
Topic: Add Some High End to Tubescreamer TS-9
Replies: 5
Views: 2351

Re: Add Some High End to Tubescreamer TS-9

Looking at Photo 13 on page 5 of the Premier Guitar DIY article that Eddie T linked, the fastest way to add more treble is to replace C5 (.22uF Tant) with a .1 or .12 value capacitor. Poly, MKT or box types will work fine. Or do the conversion of the Tone control from active to passive by following ...
by blackbunny
07 Jul 2017, 04:15
Forum: Parts Sourcing & Trading
Topic: TL071 Substitutes
Replies: 4
Views: 2116

Re: TL071 Substitutes

The "Tube Sound Fuzz" uses a CD4049 CMOS Hex Inverter IC, which is not related to the TL071 or TL072 at all and cannot be substituted under any circumstances. Most other Craig Anderton projects use a Raytheon RC4739 or XR4739 dual op amp IC, or a RC4136 quad op amp IC, all of which are now...
by blackbunny
21 Aug 2016, 05:14
Forum: Boutique Stompboxes dissected...
Topic: Menatone None More Black version 1
Replies: 5
Views: 8169

Re: Menatone None More Black version 1

Thanks for sharing this.:thumbsup You can post the schematic to the Menatone NMB topic already running in Boutique Stompboxes http://www.freestompboxes.org/viewtopic ... 8&start=20 to avoid duplicate threads. :secret:
by blackbunny
21 Aug 2016, 05:06
Forum: Amplifiers
Topic: Need advise with simple mods valveking.
Replies: 4
Views: 2802

Re: Need advise with simple mods valveking.

Can you post the schematic for the Valveking 20 MH? It's pretty confusing trying to figure out what you are asking, using the partial board layout you posted.
by blackbunny
18 Aug 2016, 15:07
Forum: Amplifiers
Topic: Marshall MA 100C 100 Watt All Valve Amplifier
Replies: 146
Views: 73144

Re: Marshall MA 100C 100 Watt All Valve Amplifier

You are most welcome. The countless hours I spent testing and fixing my 2000 Marshall TSL100 has taught me a lot, some of which I was able to use on Dr Nomis' amp. One thing it taught me is never buy a Marshall made after 1985. The TSL100 has got to be the worst valve amp I've ever owned, whereas I ...
by blackbunny
18 Aug 2016, 14:43
Forum: Amplifiers
Topic: Early KT66 date coding
Replies: 2
Views: 1824

Re: Early KT66 date coding

As it's GEC branded rather than Marconi or Osram, the date code could translate as L = 1955 and 5 = May. :hmmm:
by blackbunny
16 Aug 2016, 05:23
Forum: Amplifiers
Topic: Marshall MA 100C 100 Watt All Valve Amplifier
Replies: 146
Views: 73144

Re: Marshall MA 100C 100 Watt All Valve Amplifier

Dr Nomis asked me to try and fix his trouble prone MA100C amp after he had taken it back to the shop for "warranty repairs" ( that didn't fix the problems ) and then tried to fix it himself. I took it on as a "rainy day" repair project and after I had a few attempts at it, the am...
by blackbunny
08 Apr 2015, 04:07
Forum: Amplifiers
Topic: Bloody Little Bastard ll solid stage power amp
Replies: 42
Views: 14678

Re: Bloody Little Bastard ll solid stage power amp

Thanks for sharing the details of this amplifier with us rcustoms :thumbsup This is just what I need to fix a scorched Laney R4B bass combo amp I have here. It has the usual shorted SMD diodes, transistors and resistors that I see in blown Laney bass amps, and I really don't want to try and rebuild ...
by blackbunny
05 Aug 2014, 00:09
Forum: Modern Stompbox Effects (1975 - ...)
Topic: McGillwell - Fet Booster
Replies: 9
Views: 3727

Re: McGillwell - Fet Booster

Have you played it yet? Does the unusual combined vol / tone pot give a range of useful tones? :hmmm:
by blackbunny
29 May 2014, 00:56
Forum: Boutique Stompboxes dissected...
Topic: MusicMan Phasor
Replies: 9
Views: 2076

Re: MusicMan Phasor

The Rotor Spear (H&K Rotosphere clone) power supply diagram shows one proven method of deriving various DC supplies from a single AC source. You're getting a handle on it. The fastest way to find out what's going to work would be to go ahead and breadboard it according to your original idea, der...
by blackbunny
27 May 2014, 00:24
Forum: Boutique Stompboxes dissected...
Topic: MusicMan Phasor
Replies: 9
Views: 2076

Re: MusicMan Phasor

blackbunny, this is very helpful! This is what I thought as far as the power supply goes, but I would not have thought to change resistor values and the cap. I'd love to run the phasor on 16v, but the Max1044 fizzles above 10v, doesn't it? Yes, you're right, the 1044 'maxes' at 10v input. :roll: I ...
by blackbunny
26 May 2014, 00:49
Forum: Boutique Stompboxes dissected...
Topic: MusicMan Phasor
Replies: 9
Views: 2076

Re: MusicMan Phasor

The LFO oscillator which drives the optocouplers LDR1 & 2 uses the -16v rail to enable and disable it, which starts and stops the phasing. The whole Phasor circuit is based around IC5, IC6 and IC7 which are standard workhorse 1458 / 4558 dual op amps. Pin 8 of each op amp is connected to +16v su...
by blackbunny
16 May 2014, 01:25
Forum: Amplifiers
Topic: Marshall MA 100C 100 Watt All Valve Amplifier
Replies: 146
Views: 73144

Re: Marshall MA 100C 100 Watt All Valve Amplifier

Good advice from deltafred and bajaman - try replacing that suspect EL34 first. PM me if you don't have a spare handy and I'll try and get one to you quickly. I might just go the whole hog and just replace all the power valves anyway, although the amp sounds okay it does seem a bit underpowered for ...
by blackbunny
30 Mar 2014, 04:05
Forum: Amplifiers
Topic: Marshall MA 100C 100 Watt All Valve Amplifier
Replies: 146
Views: 73144

Re: Marshall MA 100C 100 Watt All Valve Amplifier

Simon - normally when the HT fuse blows after switching the standby on (off ? :wink: ) it is a sure sign of a bad power tube - ALWAYS check the screen resistors before replacing bad power tubes :wink: A tube tester takes the guess work away too :secret: The HT sounds about right - did you measure i...
by blackbunny
25 Mar 2014, 11:22
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Hughes & Kettner - Rotosphere [schematic]
Replies: 104
Views: 56964

Re: Hughes & Kettner - Rotosphere [schematic]

Just wondering if it's safe to plug in a 15VAC adaptor? (but I'd check the output first) How much voltage do you think a MK1 would handle safely? I wouldn't use a 15VAC supply on this pedal, 13VAC (loaded) @ 700mA - 1Amp would be the maximum. Why? All internal voltages will be be raised by about 25...
by blackbunny
06 Mar 2014, 23:41
Forum: Amplifiers
Topic: Marshall MA 100C 100 Watt All Valve Amplifier
Replies: 146
Views: 73144

Re: Marshall MA 100C 100 Watt All Valve Amplifier

If you can find the Chinese 12AX7B preamp tubes - get them - they are currently the best and most consistent emission and quality wise on the market at present I've found them to be consistently good, but they're a bit hard to find in Oz ATM for some reason. Only found one Oz seller so far: EVATCO ...
by blackbunny
06 Mar 2014, 14:23
Forum: Amplifiers
Topic: Marshall MA 100C 100 Watt All Valve Amplifier
Replies: 146
Views: 73144

Re: Marshall MA 100C 100 Watt All Valve Amplifier

Just wondering, how much would you charge me for a set of 4 matched JJ EL34 power valves and three Chinese 12AX7B valves?...... :hmmm: Not sure what valves cost over in NZ, or if bajaman sells them, but this guy is the best I've found in Oz for low prices and great service: https://www.ebay.com.au/...