Clari(not) Dry Path Sounds Muffled

Started by Zounds!, April 01, 2017, 04:31:27 PM

Previous topic - Next topic

Zounds!

I built a Clari(not) on vero using this layout: http://tagboardeffects.blogspot.com/2012/02/mid-fi-electronics-clarinot.html
Schematic: http://i10.photobucket.com/albums/a113/midfielectronics/mid-fi_clarinot.png

I wired it so there was no fuzz and ran the input through a resistor to get the signal totally clean. I also added another small resistor in parallel across pins 13/14 of the PT2399 to get rid of some nasty static on the repeats. This has served me fine for a while, but my clean tone through the circuit has never sounded quite right. If I turn the blend all the way to dry and A/B with the bypass switch, I lose a lot of high end when the is pedal engaged. This is especially noticeable if I'm running a dirt pedal into it, as it just turns out totally muffled sounding.

So I opened the pedal back up and modified mine to follow Doug's clean version:

Quote from: doug deeper on March 24, 2011, 11:19:22 AM
The buffer is a jfet, 10k resistor, and 2 10uf caps n the output.
The audio side goes through a 15k resistor to the junction on the 10k and 22k that feed the delay chip.
The other half goes from the second 10uf to the input of the 386, everthing is the same there except the .01ufcap and the 100k resistor are no longer there (so the fuzz doesn't get to the delay chip).

I sent my input through a JFET buffer and split the signal using this buffer layout: http://tagboardeffects.blogspot.com/2014/08/buffers.html (third one down). I modified that layout per Doug's suggestion, changing the 3k3 to 10k and adding a second out that goes through a 10uf cap and then a 15k resistor. I wired it up as per these instructions and removed the .01 cap and the 100k resistor from the main board. I also made a tiny solder bridge to re-connect pins 1 and 8 of the LM386, though I'm not sure if that was the right thing to do (seems to change the response of the envelope, but obviously doesn't add fuzz anymore).

The result: The pedal works as it should and is totally clean, but my clean tone is still as muffled as it was before, and now with the blend at noon it's below unity gain. reducing the value of the resistor on the output of the buffer gives me more volume, but the overall tone is still muffled.

Does anyone have any idea where on the dry path of this pedal I'm losing treble? Any tips would be a big help. Thanks!

The board:


and the input buffer:

Zounds!

Found two substitutions that I forgot about: two of the 47uf caps were 33uf (I most have been out of stock when I put it together initially). I swapped in the correct values but didn't make any difference for my treble loss problem...

Zounds!

I audioprobed and found that my signal is intact at the junction of the 10k and 22k resistors that feed the PT2399, but that I lose a fair amount of high end where they meet pins 16 and 15 (respectively). I checked for cold joints but found nothing. I pulled the PT2399 and checked without it and the sound improved a lot, though it's still noticably duller than my bypassed tone. I decided to order a few more PT2399s so I could rule that component out. In the meantime, my voltages for the PT2399 that's in there now:

1: 4.93
2: 2.46
3: 0.00
4: 0.00
5: 3.13
6: 2.47
7: 0.64
8: 0.66
9: 2.47
10: 2.47
11: 2.47
12: 2.47
13: 2.47
14: 2.47
15: 2.47
16: 2.47

and the 78L05

I: 8.57 (my power supply measures 9.30...)
G: 0.00
O: 4.93

Addy Bart

It could well be the delay chip. I've also done the clean version of the Clarinot (difference is I used a 12k where the 15k goes)... It is still a bit quiet when the blend is 50/50 but the clean signal doesn't sound dull, so maybe a new PT2399 will fix this. I also experimented with lower value caps on some of the pins... I changed the cap on pins 11 and 12 to 47nF and for pins 15 and 16 I went lower than 1nF... Can't quite remember what it was exactly. Socket them if you can.

Zounds!

Hmm yeah I guess I'll post back once my new PT2399s arrive. From looking at other people's voltages it looks like pins 7 and 8 of mine are quite a bit off, so I'll sit tight until I can try a new one. Thanks for the the confirmation that the clean signal should not sound dull (I figured as much, since it's such a popular circuit), and I'll give some different caps a shot too.