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I'm curious as to your thoughts and opinions on the concept and various implementations of modular pre-amps such as the Randall/Egnater RM series and the newer (imo unfortunately named) Synergy systems.
https://www.synergyamps.com/

I know Billy Corgan uses/d several of the Randall RM-4 rack unit with some custom modules provided by Salvation Mods
http://salvationaudio.com/index.php?page=modifications

There is also Jaded Faith mods doing this sort of thing
https://jadedfaithmods.com/

There are other Randall models out there like the RM 1250 rack, RM 100 head, RM50 combo, RM20 and RM22 heads

https://youtu.be/_eVH5vUR8u8

This is the first actually new,new guitar I've ever bought even tho it is already 5 years old. Got this straight from the Gibson Demo Shop as a factory "Mod".

2016 Gibson Non-Reverse Firebird in Vintage Copper Limited Edition with a factory added short Vibrola

It does not have the magnet rail type Firebird pickups which is kind of a bummer but these are a Classic 57 and 57+ which are great too.

The body is thin like an SG but not quite as contoured but still feels very nice

The neck is the fatter rounded profile which I much prefer to the slim taper

Is it feasible to even do, or does it just not work well enough?

Im finishing up a Setback build and yes the thru volume drop is a bit annoying. Is it something that was solved for in later revisions?

I used trimpots for R4 (200k) and R48 (100k) and even maxed out they don't seem to help. Any Ideas?

Grab a copy while you can.

Notice: You may need to right click the link and Save As

Lowpass Filter
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-101-Schematics.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-101-Owner-Manual.pdf

Ring Modulator
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-102-Schematics.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-102-Owner-Manual.pdf

12-Stage Phaser
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-103-Schematics.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-103-Owner-Manual.pdf

Analog Delay
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-104-Schematics.pdf

MuRF
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-Murf-MF-105-Schematics.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-Murf-Owner-Manual.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-Murf-Function-Description.pdf

MIDI MuRF
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-105m-Murf-Schematics.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-Mf-105m-Midi-Murf-Owner-Manual.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-105m-Murf-Notice.pdf

FreqBox
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-107-Schematic.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-107-Owner-Manual.pdf

Clusterflux
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-108m-Schematics.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-MF-108m-owner-manual.pdf

Control Processor
https://www.synthxl.com/wp-content/uploads/2020/04/Moog-CP-251-Schematics.pdf

https://www.synthxl.com/wp-content/uploads/2020/04/Moog-CP-251-Owner-Manual.pdf


You can also try the site directly:
http://www.synthxl.com/manufacturers/moog/

I'm a big fan of the Roland jazz chorus and Lab Series amps and I have been thinking about trying to build one or something like them. I don't know how it sounds but this is a small, simple, 15 watt, solid state Moog amp with a JBL speaker and it looks killer. I'd love to try to build something based off it.

Supposedly there were only 3 of these fully assembled PMS-15 amps ever sold from the early days of the R.A. Moog Company so my hopes aren't high... I'm mainly curious if anyone has a schematic for this? Videos, sound clips, pics whatever you have.




https://www.matrixsynth.com/2014/04/switched-on-birth-of-moog-synthesizer.html?m=1


There is a lot of good info in this catalog for it and apparently it was sold as a kit too.
https://moogfoundation.org/wp-content/uploads/1964-R.A.-Moog-Catalog.pdf
"The amplifier circuitry includes thirteen transistors and five diodes"


http://www.moogarchives.com/pms.htm
"The resulting instrument embodies several departures from conventional circuitry, and other design features that combine conventional components and circuitry in novel ways. "

http://moogarchives.com/forum/viewtopic.php?t=145&highlight=pms
Apparently, John had a pair of kit chassis about 16 years ago...

I ran across this and found it interesting so I thought I'd share. There are lots of other good comparison charts with steepness curves.

https://therepaircafe.wordpress.com/2019/10/24/forward-voltage-of-various-diodes/

Is it ok to use a roadrage(or the 3pdt05 bypass) with the Setback? The build doc only mentions up 12v.

MB Fritter 8HP module. I love it, sounds great

I'd like to try to replicate the elongated pill shaped, and maybe even some rectangular holes, I see in a lot of eurorack aluminium front panels. I'm using 0.09" (2.3mm) thick 6061 (so I can stomp on it). I bought a small professionally made filler panel as an example to make sure I had my measurements correct and it is thinner and feels like a softer more plyable alloy. (See pic)

Does anyone have any recommendations about the best/cheapest/most pro way to do this for a hobbiest? I wouldn't mind buying a small $100-$300 machine that I could get some other good uses out of but Im not sure what that would be yet.

Here is my scenario... I messes up and assumed the hole distance from the side was the same as the hole pitch which is 1HP (5.08mm/0.2"). It's not, it's 1.5 HP. So, (to be in compliance with the eurorack standard) I need to correct all the counter sunk holes I have already by stretching them out to the side.

Thanks for looking!

Here are some more modules for my Multi Modular Mega rack/board that I've completed over the last few months.

Anybody know of any modulation or bbd doubler daughter boards that will work with the Setback?

I populated my Setback board last night with the components I had on hand. Need to order a handful of few parts to complete.

Seems like there may be a mistake in the build doc. Shouldn't lug 1&2 be tied together on the rate pot rather than the depth?

I've been playing with this. It's pretty nifty. Anybody try it yet?

https://www.thomann.de/gb/stompenberg_devices.html

https://www.thomann.de/blog/en/stompenberg-effects/

Does something like that where you can set the rate exist as a standalone?

It looks like there may be two revision represented in the build doc. C12 is either shown as 2n7 or 3n3 depending on where you look. Any opinions on which value is preferable?

I ordered regular 47u electrolytic caps for the Blueprint without really thinking about it. These are the two power decoupling caps right off of pin 1(V+) and 2(Vref) of the PT2399.

Would low-ESR aluminum electrolytic or tantalum caps work better here to help minimize the pt2399 noise at longer delay times?

I'm newish to Eagle and circuit design in general so please be gentle...

I'm specifically looking at the VFE Blueprint Eagle file and can see it's a 2 layer board with the normal top and bottom layers. The entire top layer has hatch pour named GND. The bottom layer is split into two pours, right between pins 3 and 4 of the pt2399. The upper pour is named GND and the lower is named V+. Just trying to figure out what's going on behind the scenes. I assume this was done to separate the AGND and DGND but I can't make heads or tails of it.

In Eagle, how do you see which pads and vias are connected to cooper pours? I can see the outline for the polygons of area ofthe pours, but not much else.

I built a tractor beam phaser and am working thru some bias concerns.

The 4.3v bias zener in circuit measured low so I took it out and with a 10k resistor in a test circuit it measures at 2.5v which is about the same as in circuit. I measured another zener of the same batch and got about the same as the other? The voltage changes with the resistor value. Shouldn't this be, and stay pretty close to 4.3v? Did I get a bad batch?  Btw, these are from Mouser


I've been posting some troubleshooting steps I've on this thread. I thought the distortion was something with the JFets at first, but ( I think) it may be that the bias voltage is too low
https://www.madbeanpedals.com/forum/index.php?topic=31196.0