Search found 338 matches
- 12 Apr 2024, 00:13
- Forum: Pedal Debugging & Troubleshooting Support
- Topic: T-REX Mudhoney II loud popping sound when bypass on/off
- Replies: 1
- Views: 353
Re: T-REX Mudhoney II loud popping sound when bypass on/off
If it's a leaky cap at the input, a 1Meg or 2.2Meg resistor to ground at the input will help discharge it and reduce the pop. You can tie it to ground from the tip lead of the input jack, or the input lug on the 3PDT, mostly anywhere before the first cap at the PCB input.
- 11 Apr 2024, 22:02
- Forum: Davidoff Library
- Topic: Guitar Charts and Tabs for Jesus Christ Superstar
- Replies: 0
- Views: 559
Guitar Charts and Tabs for Jesus Christ Superstar
One of this rock opera's orchestra guitarists posted this somewhere more than 20 years ago. I forgot I had it until the topic came up on another forum. Thought I'd post it here for the record (which is the meaning of the file names: Side 1, Side 2, etc. refer to the 2-disc LP set.)
- 03 Apr 2024, 14:50
- Forum: Printed/Published Online Designs
- Topic: EarthTonesAudio: "Buster" boost/buffer
- Replies: 13
- Views: 5688
Re: EarthTonesAudio: "Buster" boost/buffer
I think the overall scheme will work, with a few changes. I'd increase the bias resistor R2 from 10k to 1M or so, depending on the bias current requirements of the op amps you select. I'd also add a cap between R3/R13 and the bias supply VA, you don't a DC path there since you're biasing the op amps...
- 25 Mar 2024, 13:11
- Forum: Printed/Published Online Designs
- Topic: EarthTonesAudio: "Buster" boost/buffer
- Replies: 13
- Views: 5688
Re: EarthTonesAudio: "Buster" boost/buffer
You may have problems with hum if you split the output to two different amps without some sort of isolation. Here is some previous work on that topic, with possible solutions: https://www.freestompboxes.org/viewtopic.php?p=296138 Split the input rather than the output, but it reduces the buffer's in...
- 23 Mar 2024, 01:14
- Forum: Pedal Debugging & Troubleshooting Support
- Topic: TA-100 'touchy' transistor
- Replies: 2
- Views: 223
Re: TA-100 'touchy' transistor
Sounds like you have a problem with your ground. Touching the case of Q2 grounds the collector thru you, when it should be grounded thru a 10k resistor already. Pin 1 of the volume pot should already be tied to ground, so grounding it directly shouldn't make any difference. Check your ground bus.
- 21 Mar 2024, 13:52
- Forum: Electric Guitar/Bass Wiring
- Topic: Baja Active EMG Schematic [schematic]
- Replies: 11
- Views: 32005
Re: Baja Active EMG Schematic [schematic]
I wonder if its suitable to use a 071 or 741 instead of 4250, as its an unobtanium already.. Either one of these should work OK, just omit the programming resistor R8 and leave the op amp pin 8 floating. I just ran across another substitute for the 4250, though it's also obsolete. If you can locate...
- 19 Mar 2024, 13:17
- Forum: Electric Guitar/Bass Wiring
- Topic: Baja Active EMG Schematic [schematic]
- Replies: 11
- Views: 32005
- 10 Mar 2024, 02:32
- Forum: Pedal Debugging & Troubleshooting Support
- Topic: Oneder Red Ryder clone
- Replies: 3
- Views: 353
Re: Oneder Red Ryder clone
Yeah, just decrease the value of R10, that first 15k resistor after the clean buffer IC2.4, to increase the clean signal level. Or increase the value of the corresponding resistor after IC2.1 (R11) to decrease the effect level.
- 22 Feb 2024, 03:36
- Forum: Modern Stompbox Effects (1975 - ...)
- Topic: Digitech - PDS 8000 Echo Plus 8 [schematic]
- Replies: 9
- Views: 38855
Re: Digitech PDS 8000 schematic [schematic]
The resolution on the PDS-8000 schematic is poor, but this source says the PDS-2000 is similar: https://falseelectronics.blogspot.com/2 ... -8000.html
So here are both.
So here are both.
- 21 Feb 2024, 18:45
- Forum: Boutique Stompboxes dissected...
- Topic: Amptweaker - BigRock/TightMetal Pro [traced]
- Replies: 63
- Views: 70091
Re: Amptweaker - BigRock/TightMetal Pro [traced]
Hi Aleksandar, Hi guys. I have a few questions and I need your advice. Can POT 100KC (antilog), LOW and TIGHT be replaced in the following way? Yes, those will work, and will give you approximately 100k antilog for each one. I have a little confusion about the A,B and C pot markings. Is this correct...
- 15 Feb 2024, 14:43
- Forum: Pedal Debugging & Troubleshooting Support
- Topic: TC Electronic Sustain + EQ low volume
- Replies: 2
- Views: 435
Re: TC Electronic Sustain + EQ low volume
For continuity and to assist troubleshooting, here's a thread on this pedal: https://www.freestompboxes.org/viewtopic.php?t=9043 Various posts there include links to the layout, BOM, service manual and schematic. Below is Harald Sabro's redrawn schematic with his notes. I would suspect either the co...
- 15 Feb 2024, 04:21
- Forum: Pedal Debugging & Troubleshooting Support
- Topic: Dunlop Cry baby JH-1 low headroom [SOLVED]
- Replies: 8
- Views: 32452
Re: Dunlop Cry baby JH-1 low headroom [SOLVED]
I don't think it should do that. If the output is clipping, I would suspect a transistor. Here's a starting point for schematics, apparently there have been several revisions of the JH-1 across time. viewtopic.php?p=267574
- 14 Feb 2024, 18:31
- Forum: Boutique Stompboxes dissected...
- Topic: Bogner - Harlow Compressor (gut shots) [traced]
- Replies: 41
- Views: 98478
Re: Bogner - Harlow Compressor (gut shots) [traced]
If you have a tone generator and a scope (or true-RMS VOM) you can use a signal to do the same. Inject 60 hz at 1V on the primary, and measure the voltage on the secondaries to get your ratio.
- 14 Feb 2024, 18:22
- Forum: Pedal Debugging & Troubleshooting Support
- Topic: True Bypass Clipping? Possible? [SOLVED]
- Replies: 14
- Views: 36238
Re: True Bypass Clipping? Possible? [SOLVED]
I think you'd need to bypass the pedal completely, since whatever it is, remains in the signal path during the current bypass method. It's a pretty small enclosure, and the bypass switch is mounted on the PCB so that might be tough unless you rehouse it in a larger enclosure to make room for a separ...
- 13 Feb 2024, 18:36
- Forum: Modern Stompbox Effects (1975 - ...)
- Topic: MXR / CAE - MC401 - Boost/Line Driver [schematic]
- Replies: 84
- Views: 85303
Re: MXR / CAE - MC401 - Boost/Line Driver [schematic]
Hi, everyone. I would like to ask it's the correct schematic? I am confused about the voltage line (V+) connects to non-inverting input but it should be connected to pin8 accordingly to the datasheet. Welcome to the forum, Eugene! This schematic, like many, doesn't show the V+/V- connections to the...
- 10 Feb 2024, 21:02
- Forum: Announcements and Forum Rules
- Topic: Heavy Spam Attacks - manual account activation [RESOLVED]
- Replies: 4
- Views: 36048
Re: Heavy Spam Attacks - manual account activation [RESOLVED]
Good job in finding and fixing this, Johan. For those who didn't see it, it was pretty bad for a day or two. Mike
- 10 Feb 2024, 15:08
- Forum: DIY Projects
- Topic: OGBip-2 overdrive on 2n5088 bipolar transistor
- Replies: 11
- Views: 910
- 09 Feb 2024, 23:31
- Forum: DIY Projects
- Topic: OGBip-2 overdrive on 2n5088 bipolar transistor
- Replies: 11
- Views: 910
Re: OGBip-2 overdrive on 2n5088 bipolar transistor
Sounds good! Your bias plan looks interesting with the two 1N4007 diodes. So the bias voltage will be about 1.2 V?
- 09 Feb 2024, 22:18
- Forum: Modern Stompbox Effects (1975 - ...)
- Topic: Goodrich - Model 7A Super Sustain Match Box [schematic]
- Replies: 4
- Views: 16075
Re: Goodrich Model 7A Super Sustain Match Box [schematic] [schematic]
I'm repairing yet another one of these, and this one has a Motorola MC33171P op amp. It's similar to the MC34181, with slightly worse specs, but still plenty good enough for this device. This op amp has a noisy output, but both the 33171 and 34181 are obsolete in PDIP, I will probably get a used one...
- 07 Feb 2024, 03:58
- Forum: Boutique Stompboxes dissected...
- Topic: 29 pedals - Euna [traced]
- Replies: 16
- Views: 31249
Re: 29 pedals - Euna [traced]
I'm curious of someone can explain to me, in as simple of terms as possible what the harmonics switch accomplishes. Thanks. If I'm reading the schematic labels right, the "harmonics" switch (labelled H+ here) puts C28 in series with C27, making an effective capacitance of 69 nF (220 nF + ...