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Madbean Total Recall is driving me nuts!

Started by Ariosto, March 15, 2019, 11:58:00 PM

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Ariosto

Hello again,
Finally I ended with the build of such ambitious project (including the expansion board). My first mistake was not reading the complete instructions and soldered the IC7 BEFORE the complex calibration process... In the desoldering process I broke one of the pins of the not cheap MN3005. OK, I resolved now to socket it just in case and installed a new one (no Chinese fake).

After my first attempt to biasing the pedal, I could achieve echo but distorted (I can easily deduce that the wiring is correct. Refering to the forums, some users experienced such issue and some claims that changing some resistances the problem is gone. But now in my second attempt the things went even worse. I become absolutely no echo signal. The Level control works and the Blend too. Although I still did not measured voltages and did not audioprobed yet, the case is confusing. Was the socketing not a good idea? Was something fried in the way? Well, I attach some pictures now. Apparently there are no cold joins but I can check with a magnifying glass again. Same thing with the wiring. In the meantime, if there is some seasoned builder around who can give me some advice or helping hand, would be great!!

Nice regards,
Ariosto

Ariosto


Scruffie

Works at Lectric-FX

Ariosto

Quote from: Scruffie on March 16, 2019, 12:06:51 AM
Can't say anything without voltages.

THANKS FOR THE QUICK ANSWER!!!

I am sort of incompetent with electronics (and even so I succeeded with most of my buildings! Including the Naughty Fish, the Aquaboy and the Stage Fright). I must take a look at some Youtube tutorials about how to make it correctly and -as Arnold Schwarzenegger once said- "I´ll be back".

Ariosto

Quote from: Scruffie on March 16, 2019, 12:06:51 AM
Can't say anything without voltages.

Hey, I am here again. I learnt quickly how to measure voltages and did my job. Well, the values I´ve got are not far away from the ones in the Total Recall PDF document. Now I hope there is some good soul out there to give me a helping hand with the build.

Here the measurements:

IC1:                                                                 IC3:                                                              IC6:
1: -7.3                                                             1: -6.51                                                        1: 0
2: -7.3                                                             2: -3.25                                                        2: -7.46
3: -7                                                                3: -3.15                                                        3: -6.59
4: -14.66                                                          4: -14.66                                                      4: -6.59
5: -6.74                                                            5: -7.18                                                        5: -14.84
6: -7.4                                                              6: -7.41                                                        6: -7.47
7: -7.4                                                              7: -7.41                                                        7: -1.93
8: 0                                                                  8: 0                                                              8: -13.82

IC2:                                                                 IC4:                                                              IC7:

1: -13.43                                                         1: -7.41                                                         1: 0
2: -12.78                                                         2: -7.41                                                         2: -7.46
3: -12.78                                                         3: -7.06                                                         3: -11.49
4: -14.66                                                         4: -14.66                                                       4: -11.64
5: -12.86                                                         5: -8.53                                                         5: -14.84
6: -12.67                                                         6: -8.76                                                         6: -8.76
7: -4.78                                                           7: -8.76                                                         7: -8.76
8: -12.86                                                         8: 0                                                               8: -13.85
9: -12.86
10: -6.74
11: --8.41                                                       IC5:                                                               IC9:
12: -12.87                                                      1: -7.41                                                          1:Varies
13: 0                                                              2: -7.41                                                          2: -7.09
14: -12.78                                                      3: -7.18                                                          3: Varies
15: -12.78                                                      4: -14.66                                                        4: -14.84
16: -13.45                                                      5: -6.13                                                          5: -7.12
                                                                      6: -6.74                                                         6: -7.12
                                                                      7: -6.74                                                         7: Varies
                                                                      8: 0                                                               8: 0

IC8:                                                              IC10(TRXPN):                                                   IC11(TRXPN):
1: -7.48                                                         1: 0                                                                 1: 0
2: -7.35                                                         2: -7.46                                                           2: -7.46
3: -7.22                                                         3: -5.34                                                           3: -12.13
4: 0                                                               4: -5.33                                                           4: -12.13
5: 0                                                               5: -14.82                                                         5: -14.84
6: 0                                                               6: -7.46                                                           6: -7.46
7: -14.84                                                       7: -2.98                                                           7: -12.82
8: -14.84                                                       8: -13.86                                                         8: 0
9: -14.84
10: -7.47
11: -7.47
12: -14.84
13: -7.47
14: 0

REG LM7915
I: -23.1
G: 0
O: -15
                                               

Ariosto

IC6 pins 3 and 4 must be -10.12 in my pcb measues only -6.59. IC7 pin 3 and 4 are in my build around 11.49 and must be 9.71. I think the rest are barely slightly different but I am a noobie.

Scruffie

I didn't see in your pictures that you're trying to use 2 x 3005 and 2 x 3008, the 4047 clock is only good for driving 2 x 3005 unaided, that will probably cause issues.

The voltages on this look mainly fine apart from your BBD bias voltage on IC6 is definitely too low and IC7 is probably a little high, plus pin 6 & 7 measure the same but I'm thinking that's probably a typo but worth checking again in case there's a short there.

Works at Lectric-FX

Ariosto

Quote from: Scruffie on March 18, 2019, 10:34:27 PM
I didn't see in your pictures that you're trying to use 2 x 3005 and 2 x 3008, the 4047 clock is only good for driving 2 x 3005 unaided, that will probably cause issues.

The voltages on this look mainly fine apart from your BBD bias voltage on IC6 is definitely too low and IC7 is probably a little high, plus pin 6 & 7 measure the same but I'm thinking that's probably a typo but worth checking again in case there's a short there.



Thank you very much for the reply!
Als I already said, I am a noob who is slowly learning yet. You mean, I must replace the two MN3008 in the TRPXN, or the CD4047 instead?

Scruffie

Get rid of the TRPXN board and re-bias your two MN3005.
Works at Lectric-FX

Ariosto

Quote from: Scruffie on March 19, 2019, 11:59:59 AM
Get rid of the TRPXN board and re-bias your two MN3005.

OK, I´ll do it. The question is, can I after the re-biasing connect again the TRPXN, or is it completely useless?

Ariosto

From the Madbean´s TRXPN PDF Document:

"The TRXPN is an expansion board for the Total Recall project. It allows one to use four MN3008 BBDs in place of two
MN3005 (both totaling about 550ms of delay). The TRXPN has its own bias trimmers for the two added BBD stages and
when wired to the TR main board, they are inserted as stages 2 and 3 of the delay."

Does it mean that if I installed two MN3005 in the Total Recall and two MN3008 in my TRXPN could I have incompatibility issues?

Scruffie

The document is saying you can use either 2 x MN3005 OR 4 x MN3008.

So the short answer is settle for the 2 x 3005 and use the TRXPN board elsewhere.
Works at Lectric-FX

Ariosto

Quote from: Scruffie on March 19, 2019, 07:34:50 PM
The document is saying you can use either 2 x MN3005 OR 4 x MN3008.

So the short answer is settle for the 2 x 3005 and use the TRXPN board elsewhere.

I have no idea where else could I use the TRXPN. I thought it was designed only to use with the Total Recall. Yet another stupid question: What if I change to the 4 x MN3008 configuration?

MacHeath

Then you'll have 2 extra MN3005 you can use on another project!

Ariosto

BIASING REPORT AFTER TRXPN-OUT:

..... Disconnected the TRXPN (as the user Scruffle recommended), I began with the biasing procedure again. The bad new is, that the Total Recall refuses to work. Although the "Level" and "Blend" controls are working normally, but not the Delay and consequently the Feedback knobs. Anyway I proceed according to the instructions in the PDF document:

IC7 removed
DELAY - full up
FDBK - a little less than halfway up
MOD - all the way down
LEVEL - about 1/3rd up
BLEND - doesn't matter (you should leave the circuit output disconnected since we will be audio probing)
CH/VB switch - doesn't matter
All the trimmers in their halfway position to start

Well, I become audio signal WITHOUT DELAY through the audio probe in IC6 (pin3 sounds louder as pin4). Adjust the trim until becoming undistorted signal.
In IC4 pin7 I became distorted audio signal, and GAIN 1 makes no variation as I rotated the trimpot.
Reinstalled IC7 and still no delay signal........

Is maybe the 4558 in IC4 dead? As curiosity, I checked the other ICs with the audio probe and I become signal in everyone of them. I could check the wiring again, but it worked more or less good before. Very strange.

Hope that someone could give a tip, thanks in advance!
Ariosto