Search found 76 matches

by MullisMan
11 Jul 2019, 12:39
Forum: Boutique Stompboxes dissected...
Topic: Wampler - Ego Compressor - Gut Shots
Replies: 38
Views: 15194

Re: Wampler - Ego Compressor - Gut Shots

That board is incorrect, I need to take it down from OSHpark. There are still errors in the schematic. The ego comp has probably been updated by now anyway. Is this something people still want to build? No sarcasm intended there.
by MullisMan
30 Aug 2018, 14:46
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

Sorry to Necro a thread. I never did verify this exact schematic, but If you reconfigure the BYOC Amp Selector project to only be single channel with a transformer to isolate and then connect it to an XLR, you get the same result. Then build a receive module (i'll attach the schematic here) and you'...
by MullisMan
19 Jun 2015, 12:37
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

UPDATE After I realized that the pinouts I was using for the JFET and BJT in the input section were incorrect and per Coldcrafts correction, I decided that I'd rather do this whole thing with OpAmps. So I left the power section the same but I added another op amp for the input section. The opamp bu...
by MullisMan
09 Jun 2015, 18:35
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

Now i'm tasked with finding a transformer with comparable qualities to the original Allied Components model. From the datasheet here: http://www.alliedcomponents.com/tf_pdf/AEE19-3460.pdf , it looks like the transformer has a ratio of 1:1. The DC resistance is a little harder to match up on Mouser, ...
by MullisMan
09 Jun 2015, 17:30
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

that JFET/BJT buffer is probably arranged more like the first example in this diagram, [ Image ] The funny opamp thing with the complimentary BJTs is a virtual ground for a split rail power. The box is powered by 15V and regulated to 12V, from which R8 and R6 generate +/- 6V where "GND" is buffered...
by MullisMan
04 Jun 2015, 16:19
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

nickthemen wrote:Looks like power sag from the roland blues cube?
Hmm it does look kind of similar except for the IC connections. :hmmm:
by MullisMan
03 Jun 2015, 18:58
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

Yes I do, and I usually use audio taper as well, because you don't hear enough of a change during the rotation when you use linear. But alot of other things about this schematic make no sense to me - like everything around the 4558 and the two larger transistors. I don't see their purpose in the ci...
by MullisMan
03 Jun 2015, 17:58
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

Variable input Z is a 1M pot in series with a 22k resistor? Exactly the same values I use! :shock: Yep, although in the unit they're using the dual gang pot, but the other half of it is just grounded. There were some empty spots on the PCB for other resistors and caps so maybe it was from an earlie...
by MullisMan
03 Jun 2015, 12:21
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

Update #2 I kept looking at how the input section connected to the JFET 2N4393 (the symbol for this NPN Jfet was corrected in this update as well). I realized that the pinout that I had used was incorrect and changed the gate and drain connections accordingly. This looks much better. I also connect...
by MullisMan
02 Jun 2015, 00:58
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Re: Radial Engineering - SGI (Studio Guitar Interface) [traced]

Update I looked over the schematic and PCB again tonight, and I've made some corrections to the schematic. Pin 5 on the IC should have been going to the 1/2 supply voltage, labeled Vb in the new schematic, not Vr. Vr is actually the ground pin connection from the regulator. I also added a Vr pin to...
by MullisMan
01 Jun 2015, 15:05
Forum: Boutique Stompboxes dissected...
Topic: Radial Engineering - SGI (Studio Guitar Interface) [traced]
Replies: 14
Views: 8239

Radial Engineering - SGI (Studio Guitar Interface) [traced]

Hey fellow FSB'ers. It's been a while since I've contributed but I just bought one of these Units for recording some guitar parts. This thing is really useful for when you need to isolate the amp far away, the SGI makes it a piece of cake. I took the boards out of the enclosures and took some photos...
by MullisMan
25 Nov 2014, 20:27
Forum: Amplifiers
Topic: Dr.Z For All
Replies: 113
Views: 67735

Re: Dr.Z For All

Hello all. I've gone back through the StangRay Layout that was included in the zip files and created a schematic that is more consistent with junctions and corrected the power section. I left off the effects loop from the original StangRay as I won't be including it in my build. Let me know if anybo...
by MullisMan
24 Nov 2014, 16:41
Forum: Amplifiers
Topic: Dr.Z For All
Replies: 113
Views: 67735

Re: Dr.Z For All

Does anybody have better gut shots of the StangRay? I'd like to come up with a more accurate schematic than the ones shown in the zip files here. From what i've read, Bkeck and the OP built a working clone from the layout and BOM, but I like to have all the information I can before I get started on ...
by MullisMan
11 Oct 2013, 10:59
Forum: Stompbox Builder's FAQs & How To's
Topic: Mictester Relay Switching Scheme - Still have switch pop
Replies: 8
Views: 6816

Re: Mictester Relay Switching Scheme - Still have switch pop

I tried Mictester's suggestion and Lucifer's; I placed pulldown resistors at the input and output of my circuit, and I also placed a cap across the LED junction to ground. This still didn't cure the pop, so I took the LED completely out of the circuit for the time being, and also took the charge pum...
by MullisMan
05 Oct 2013, 20:40
Forum: Stompbox Builder's FAQs & How To's
Topic: Mictester Relay Switching Scheme - Still have switch pop
Replies: 8
Views: 6816

Re: Mictester Relay Switching Scheme - Still have switch pop

Yes, sorry I wasn't clearer. The pulldown resistors are at the circuit input and output, not the input/output jack. Standard voltage divider to ground. I've tried to alleviate all the sources of popping, and i'm not sure where to turn to next.
by MullisMan
05 Oct 2013, 12:58
Forum: Stompbox Builder's FAQs & How To's
Topic: Mictester Relay Switching Scheme - Still have switch pop
Replies: 8
Views: 6816

Re: Mictester Relay Switching Scheme - Still have switch pop

Thanks for the reply Mictester. I have a 1M pulldown resistor at the input and I tried putting a 2.2M resistor to ground at the output as well, no change, still have the popping. My circuit has a 1K resistor in series with the output as is, I had hoped that would take care of most of the problem.
by MullisMan
05 Oct 2013, 12:27
Forum: Stompbox Builder's FAQs & How To's
Topic: Mictester Relay Switching Scheme - Still have switch pop
Replies: 8
Views: 6816

Mictester Relay Switching Scheme - Still have switch pop

I installed Mictesters relay bypass scheme into an effect that had a lot of popping with the 3PDT switches from Mammoth/4 site. I wanted to cut down on said popping using the relay. I have installed the scheme using a 40106 Schmitt Trigger and the Takamisawa AL5W-K relay but I am still getting a pop...
by MullisMan
18 Aug 2013, 00:30
Forum: DIY Stompbox designs
Topic: Relay Switching Using 555
Replies: 35
Views: 9323

Re: Relay Switching Using 555

Sorry for resurrecting this thread, but I'm just now exploring using relay based switching instead of the abominable 3PDT. I've been using charge pumps in my designs lately and it's giving me a hellacious amount of popping; I don't even want to consider selling my products to people with that amount...
by MullisMan
24 Dec 2012, 15:47
Forum: Boutique Stompboxes dissected...
Topic: Xotic - AC Booster [ goop-alarm ] [traced]
Replies: 129
Views: 39598

Re: Xotic - AC Booster [ goop-alarm ] [traced]

I took the original AC and replaced the tranny buffers with a TL072 op amp for in/out buffering. Everything is working great, but I'm not seeing the same volume range that the original AC has. With the volume pot maxed (100kA) i'm getting more than unity gain, but not by much. I'm wondering if it ha...
by MullisMan
30 May 2012, 18:46
Forum: Circuit Blocks
Topic: Input Output Impedence ?'s
Replies: 5
Views: 10091

Re: Input Output Impedence ?'s

This should help you out. Much better than writing a long reply post.

http://www.muzique.com/lab/imp.htm