v3205 Build Report (post Final Solution Errata)

[MadeByMike]

Hi guys







So I've finished my DirtBagDeluxe (well outside of boxing it anyway) and I'm pleased to say I'm really happy with the results - the modifications to the BOM for the v3205 suggested here:

http://www.madbeanpedals.com/forum/index.php?topic=3366.0

I also have TL082s in IC1,IC3 and IC8 as I only had one TL072

Here are my IC voltages for anyone who needs them after doing these mods:

Supply = 9.22V

IC1:
pin1-3: 4.62
pin4: gnd
pin5-7: 4.6
pin8: 9.22

IC2:
pin1: 1.30
pin2-3: 1.80
pin4: GND
pin5-6: 1.80
pin7: 7.66
pin8-9: 1.80
pin10: 6.7
pi11: 4.5
pin12: 1.80
pin13:9.2
pin14-15: 1.80
pin16: 0.7

IC3:
pin1-3: 4.6
pin4: GND
pin5-7: 4.6
pin8: 9.22

IC4:
pin1: GND
pin2: 4.6
pin3-4: 6.43
pin5 : 8
pin6: 4.63
pin7: 5.85
pin8: 8.17

IC5:
pin1: GND
pin2: 4.63
pin3-4: 6.17
pin5 : 8.17
pin6: 4.63
pin7: 5.69
pin8: 7.94

IC6:
pin1-3: 5.69
pin4: GND
pin5-7: 5.22
pin8: 9.22

IC7:
pin1: 2-6 V moving
pin2: 4.61
pin3 4-5V moving
pin4: GND
pin5-6: 4.64
pin7: 4.4-4.8V moving
pin8: 9.22

IC8:
pin1-3: 4.62
pin4: GND
pin5: 6.65
pin6-7: 6.72
pin8: 9.22

IC9:
pin1: 4.48
pin2: 4.7
pin3: 4.79
pin4-6: 9.22
pin7-9: GND
pin10-11: 4.62
pin12: GND
pin13: 4.5
pin14: 9.22

Whew that took a while. So I think it sounds great - yes there is some background hiss when the repeats are kicking in and yes the compander does seem to snap shut a little tight when repeats do tail but after doing the bias process a few times I've managed to get it set up where delays sound nice and can also self oscillate if I want, so I'm a happy puppy.

Many thanks to all who helped especially Brian and Scruffie for the fixes, and Lacesensor and Tenwatt for doing the troubleshooting builds. It wasn't simple and I'm not proud of some of my part replacements, I just couldn't get those resistors out so had to resort to tack soldering from above, which is ugly, but there you go.

ALSO: it's picky about power. I was gutted when trying to bias it at first when daisy chaining it on my FAME desktop supply until I used a high mA output, and it's happy daisy chaining on my switched mode Diago powerstation style supply too - so make sure you have it getting plenty of juice!

Hope this is useful to folks

Cheers
M

[madbean]

I'm very pleased to hear that you are satisfied with the results. I know it was a pain to make those changes.

Do replace those TL082s with 72s at some point. You should hear a noticeable improvement in the noise floor.

Pin7 is on the compander looks a tad high to me...did you end up with 33k for R11 and 12?

[MadeByMike]

Will do on the TL072s, and I used 47k for r11 and r12 as recommended?

[mjcyates]

Mike, glad to hear you got it going!

[lloyd17]

Thanks for the report Mike. Gotta say at this point I'm pretty apprehensive about building mine up.

[MadeByMike]

Pin7 is on the compander looks a tad high to me...did you end up with 33k for R11 and 12?

Is this something for me to be concerned about considering I used 47Ks? You can see them in the images if you look close...

Would fixing this make biasing cleaner?

Anything else I should check? The only sub I did around that point was that R14 was 47K instead of a 51K

[MadeByMike]

Would still be interested in your opinion on that last point, Brian?

Here's the decal my friend designed for me for my pedal



Don't let the madebymike fool you, I'm not building this for anyone else. It's (along with a Current Lover) my present to myself after a year of working my arse off!

[madbean]

Pin7 is on the compander looks a tad high to me...did you end up with 33k for R11 and 12?

Is this something for me to be concerned about considering I used 47Ks? You can see them in the images if you look close...

Would fixing this make biasing cleaner?

Anything else I should check? The only sub I did around that point was that R14 was 47K instead of a 51K

No, 47k is correct. I was mis-remembering the nominal output voltage there (probably from all the tweaking).

[MadeByMike]

Thanks, I should be putting some TL072s in and getting this boxed up shortly - to be honest I can't wait!

[nzCdog]

Beaut finish Mike!
Jus like a bort one

[MadeByMike]

Thanks! It's now finished:









Really happy with how it came out - a beautiful sounding delay.

[LaceSensor]

Very nice.
Gonna be a while longer for me nevermind all comes to those who wait.

[pryde]

Awesome. Glad to here of a successful v3205 build. Do you still have noticable distortion and biasing issues? Maybe you could post a demo soon?

thanks

[marmaliser]

Very Nice

[MadeByMike]

Awesome. Glad to here of a successful v3205 build. Do you still have noticable distortion and biasing issues? Maybe you could post a demo soon?

thanks

Yeah I'll try and knock up a demo soon. When I was first trying to bias it using my desk power supply I was getting a lot of nasty distortion I couldn't dial out and I was quite upset but when I got it on a decent daisy chain (I use the johnny shred freak supply which is very similar to the Diago Power Station) it was much happier and biased up nice and clean. I now have it sounding nice and clean and also able to self oscillate aswell.