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I finally got round to building the VFE Dragon I bought several years ago.  I can't seem to find a copy of the build doc on the site.  Does anyone have any info on the trimmers inside and the frequency sweeps  of the to filters? 

I'm getting low voltage issues at most points.  The leds blink fine.  With the input of a signal generator I can hear some affect on the signal.

For example:

On pin 2 of the LT1054 charge pump it reads 2.78 when it's supposed to get 5.  Pin 8 shows 8.28 when the expected value is 9.26.

On both MN3005s  all pine are reading 50-60% of expected values.  Same with the TL072.

Is this simply a wrong resisted early in the power circuit or something more complicated?
Thanks

I think my prior post on this got lost.  Is there any way to purchase a couple boards as I cannot locate the last 2 I need.
Thanks

I have a couple left to build but for some reason I don't have the switching boards.
Thanks

I'm building a Crowther Hot Cake that calls for a 10v zener.  Will a 9.1 volt work OK?
Thanks

Just bought (for me) a new book "Pedal Crush" (c 2019).  Over 360 pages of all the various types of guitar effects, their history, how they work and interviews with the inventors and users.  Hundreds of photos of various pedals and brief descriptions.  A highly recommended book.  It's price though, $80+ delivered.  You can't yet get it though Amazon.  O bought it from, I think, the publisher.  Sweetwater has it as well.

The build doc says both of the 308s should have voltages at pins 1 and 8.  On the one I built those pins have zeron voltage on those pins.  The schematic is not clear which pins are which on either IC.  All the other pins on these 2 and the other 2 ICS are dead on correct.
TIA

Got back to this. (Referring to lab5-schem-2)  Looking at the  Master Volume, Compressor, Outout part of the schematic.  I have trace a very good clean signal to R76.  I get signal on both sides of the resistor.  I still have a signal into C36.  Now, assuming I understand the schematic, there is no signal anywhere in Q1.  There is continuity from C36 to the bottom leg of Q1. I have replaced C36 as well.

Is there anything else to check? 

Just realized I don't have one.  Some research shows that 2 polarized in series (net to net) should work.  I measured it and the capacitance is correct.  Anything else I need to know?
Thanks

Finished it and after finding out I had both voltage regulators (7815, 7915)reversed I need to see why it does not work.
Doc: https://www.dropbox.com/s/dnizjzbetec84gu/aion-lab-series-preamp-documentation.pdf?dl=1

1. Since I had the VRs reversed should I expect damage to them or any downstream components.  They got hot when reversed and still get hot when inserted properly.

2. The AC power source measures about 12 volts and not 9.

3. When measuring voltages,  since I'm not a circuits expert, should the meter be set on AC or DC voltage?  The board has  +/- 15v testpoints.  AC or DC?   

Thanks!

I'm in the process of checking out a Flabulanche and finding that the batch of LT1054's all cause a squealing noise in the output.  I had tried one of these 1054's in another pedal with the same result but did not get around to trying the other 2 part before I found a different 1054 that was OK.

Is this more likely a bad batch of parts or is there something I can do to alleviate the squeal?
Thanks

I just realized that I had forgotten to pay attention to capacitor voltage and was running it at 18 volts.  What are the symptoms of doing this?  I'm getting occasional sound out of the distortion side that sounds great.  The thing seemed to worked before boxing it and now works sometimes after taking it back out of the box.

Alternatively I also think my real problem is some type of connection issue on the board itself.  I can always trace a good signal to lug 3 of the volume pot.  Only some of the time does it the signal come out of lug 2 and make all the way to the output connection.  The pot is OK as I switched it out and checked the new one before attaching it.    The signal at R23 is also fine (as expected).  I've re-flowed solder on the parts from IC3 to the volume pot.

Here's the schematic:  http://home.comcast.net/~gprause/BuildDocs/T-Wrex_II_V3.2_Build_Doc.pdf

Any info is greatly appreciated.  This things sounds awesome when I can get sound out of it.

deleted - the thing worked today

Been struggling with this for a while and just came back to it.
Build doc: http://madbeanpedals.com/projects/Retrograde/docs/Retrograde_2014.pdf
Basically there is no signal past the base of Q1 (using an audio probe).  I've checked cap orientations and resistor values.  Switched out all the transistors.  Turning off the power give me a straight guitar signa; out.  No visible shorts on the solder side.  I'm not sure exactly  if and when the transformer comes into play.  I've built dozens of pedals without issue but this one has me stumped.

Here are the voltages at the transistors:

Q1 2N5087
---------------
C  .02
B  2.71
E  4.30

Q2 2N4401
---------------
E  ~9
B .02
C 0

Q3  2N4401
----------------
E  8.91
B 0
C 0

Thanks for any help.
BD

I'm not asking about the specifics of any one pedal type but the physical boards themselves.  I've found that some sellers make boards where the solder holes (lack of a better term) are a bit larger with more metal to which to solder.  On my list for this is madbean, aion, and rullywow.  At least for the boards I've purchased so far. 

Some board makers have the holes smaller and with less metal to solder to.  For me this comes into play when I have to remove/replace a part and the metal around the hole tends to come apart or just fall out. 

Once place from the UK has this problem which leads me to almost always have some type of trouble with their boards.  The boards from the above sellers work almost always at first power up or after checking connections.

Don't even get me started on vero boards.   I have far better luck etching my own.

Was perusing Aliexpress looking for enclosures and this popped up:

http://www.aliexpress.com/item/Free-Shipping-Guitar-Effect-Pedal-Ultimate-Drive-True-Bypass/947755892.html?s=p

It appears to be a new  Fulltone OCD for $38 from China.  Not that I'm buying (I'm building one at the moment) but this has to be a fake.  The real ones are made in California, according to their web site.

and what else may have gotten damaged?  I forgot to reverse it when I did the Si version of the pedal.  I get good sound up to the base of Q3 and then some quiet buzzing on the collector.  I think I have the transistors oriented properly as the pedal seems to work fine up to that point. 

The plan is to do some detailed debugging and then post the details when if I can't get it to work.  But I wanted to see if there was an obvious answer to a fried diode.  Matches my board designation.
Thanks

I was asked to post some build info based on my post over on the Buy/Sell/Trade forum.  So I'll gladly show what I've done for the Timmys.  I've been building effects off and on since the 1970's after I got a copy of Criag Anderton's "Electronic Projects for Musicians".


This was version used the pcbs I had made.  This one was to verify the board.   As you can see it's wired pots.  I usually hate wired pots but braiding the wires helped tame the mess.

I used a DPDT switch because I had no DIP switches at the time.   The footswitch is on a GuitarPCB board.  Used 24 gauge wire throughout and I buy parts mainly from Tayda.  It's in an unpainted 125B enclosure which I use exclusively since it's pretty cheap from Tayda and a bit larger than 1590B. 

I used a 1458 IC after testing 4558 and 072.  It seemed to have the most gain and least noise.  Since I'm not an expert on the details of these 3 chips and assumed there would be little difference, I was surprised that the 4558 had the least gain of the 3. I tried the 1458 after seeing several recommendations on other boards.

Overall it was a pretty simple build which, overall, took about an hour to put together and test and put into the box. 
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The version below was made from a PCB I received on the down-low from another online PCB seller.  It has board-mounted pots which I prefer.  I didn't post the insides as it's pretty messy compared to the above, even with the wired pots.  As you can see I painted this one and added decals.



The 2 versions do not sound identical but close enough even though, I think, they are part for part the same.  I'd have to go back and check.  There are not too many variations on this circuit from what I've seen on various forums.