Surfy Bear - Reverb

kinski · Post by **kinski** » 17 Feb 2021, 03:29

Hoping I could get some help here.

I'd like to have indepent control of the Dry and Wet signal.

Could I modify the single mix pot and use two mix pots instead? One for dry and one for wet?

Pot A
1 to Dry signal, 2 to output, 3 to ground

Pot B
1 to Wet signal, 2 to output, 3 to ground

Would this work?

Would I need some isolation resistors on leg 2 of both Pots to output?

kinski · Post by **kinski** » 17 Feb 2021, 14:49

Doesn't seem like there is much interest in this. But I'll report back anyway in case someone finds this helpful.

I had a chance to try this idea out and it worked perfectly. Now I have totally independent controls for Dry and Wet levels. And another nice thing about this set up (at least for me) is that the Dry tone no longer becomes muffled at any setting.

The Dry and Wet pots are 250k. Should my isolation resistors also be about 250k? I used 100k and it seems fine but wondering if matching the 250k is ideal. Would any resistor under 250k be attenuating the signal? Anyone have thoughts on this?

Manfred · Post by **Manfred** » 17 Feb 2021, 15:36

kinski wrote: ↑17 Feb 2021, 14:49 Doesn't seem like there is much interest in this. But I'll report back anyway in case someone finds this helpful.

I had a chance to try this idea out and it worked perfectly. Now I have totally independent controls for Dry and Wet levels. And another nice thing about this set up (at least for me) is that the Dry tone no longer becomes muffled at any setting.

The Dry and Wet pots are 250k. Should my isolation resistors also be about 250k? I used 100k and it seems fine but wondering if matching the 250k is ideal. Would any resistor under 250k be attenuating the signal? Anyone have thoughts on this?

Please be patient, I will look into it.

Manfred · Post by **Manfred** » 17 Feb 2021, 20:24

A solution with a passive circuit has only disadvantages.
A solution would be to lead the two potentiometer outputs for dry and wet signal to a small summing circuit with an operational amplifier.

tome.talevski · Post by **tome.talevski** » 03 Apr 2021, 10:59

kinski wrote: ↑17 Feb 2021, 03:29 Hoping I could get some help here.

I'd like to have indepent control of the Dry and Wet signal.

Could I modify the single mix pot and use two mix pots instead? One for dry and one for wet?

Pot A
1 to Dry signal, 2 to output, 3 to ground

Pot B
1 to Wet signal, 2 to output, 3 to ground

Would this work?

Would I need some isolation resistors on leg 2 of both Pots to output?

Screen Shot 2021-02-16 at 10.20.59 PM.png

Hey Kinski!

Any chance you might have a Vero layout for this?

Cheers

kinski · Post by **kinski** » 03 Apr 2021, 11:57

Sorry, no. I had a PCB from a few years ago.

Post by **The G** » 03 Apr 2021, 19:58

Here's an active solution. I fought hard with myself to leave the rest of the circuit alone, although I find the tone circuit weird and inefficient. Oh well...

The veroboard connects in place of the MIXER potentiometer and, of course, to the power supply. I used the second op amp to restore the phase of the signal, since I couldn't think of anything better to do with it. One could potentially use the inverted output at pin 1, too.

kinski · Post by **kinski** » 03 Apr 2021, 20:01

Oh man, thanks for this. However I’ve finished the Surfy Bear. It works great just giving the dry and wet their own pot followed by summing resistors.

Post by **The G** » 03 Apr 2021, 20:03

Oh, it was directed more to @tome.talevski, since he asked for a vero.

kinski · Post by **kinski** » 03 Apr 2021, 20:04

Ah, got it.

tome.talevski · Post by **tome.talevski** » 03 Apr 2021, 21:22

The G wrote: ↑03 Apr 2021, 20:03 Oh, it was directed more to @tome.talevski, since he asked for a vero.

Thanks for responding so quicky! Unfortunately, my skills limit me to reading and boarding much smaller schematics and my Vero request was with regards to the schem that Kinski posted. Not sure if anyone knows if there's a layout for the whole thing?

kinski · Post by **kinski** » 03 Apr 2021, 21:27

I know there are some other reverb kits on the market somewhere. Can’t think of the names now. Not of the 6G15, but probably still sounds nice.

tome.talevski · Post by **tome.talevski** » 03 Apr 2021, 21:41

kinski wrote: ↑03 Apr 2021, 21:27 I know there are some other reverb kits on the market somewhere. Can’t think of the names now. Not of the 6G15, but probably still sounds nice.

Im going to attempt the "ruthenium reverb' over at guitar-fx... reviews are quite positive. It uses the much smaller accutronics blue spring tank however am thinking id like to make one that can drive a larger spring tank.

kinski · Post by **kinski** » 03 Apr 2021, 21:42

http://hamptone.com/products/sr1-kit/

kinski · Post by **kinski** » 03 Apr 2021, 21:48

https://moodysounds.com/en/universal-re ... omponents/

tome.talevski · Post by **tome.talevski** » 04 Apr 2021, 09:51

kinski wrote: ↑03 Apr 2021, 21:48 https://moodysounds.com/en/universal-re ... omponents/

Thanks for those Kinski! I came across the moody option also.. hoping someone out there has the time and inclination to create a layout incorporating The G’s wet dry mods!

Post by **The G** » 05 Apr 2021, 01:35

Here is the ugliest vero you'll ever see

.
I was curious how hard it is to make a vero for a complete circuit. Well it is really hard, at least for me. I'm not seeing myself using veroboard for anything with more than 20 parts, ever.
This mod makes use of the op amp buffers to isolate the circuit blocks. It is also possible to use the inverted output, if one feels like it.
Let me know if you find issues.

kinski · Post by **kinski** » 05 Apr 2021, 01:41

Amazing! It should be mentioned that Q2 and Q7 get very hot and MUST have a heat sink yet also isolated from ground. I used some heat sink tape for isolation and screwed them directly to the reverb unit enclosure. Might be best to mount them off board then run wires to the vero.

phatt · Post by **phatt** » 05 Apr 2021, 12:00

tome.talevski wrote: ↑04 Apr 2021, 09:51
kinski wrote: ↑03 Apr 2021, 21:48 https://moodysounds.com/en/universal-re ... omponents/
Thanks for those Kinski! I came across the moody option also.. hoping someone out there has the time and inclination to create a layout incorporating The G’s wet dry mods!

As I have built many reverb circuits I would suggest researching before just building and hoping for the best.

Spring Reverb circuits are quite tricky and although a lot will deliver reverb,, many are less than impressive. (I should know cause I've built many and a lot are crap)

Number one thing to Know with Spring Reverbs,,, The tank has to match the circuit you wish to build.
If that is not close then you are building something that will frustrate you and likely end up in land fill.

Not at first obvious but Rod Elliot sells PCB's which can be modified for Reverb circuits,, It might help you

https://www.sound-au.com/project34.htm

There is a ton of really useful info on Spring Rev here and hard to find this info elsewhere.

My circuit idea of using a small Tx for hiZ drive tanks is found on this page.
Rod kindly refined it.
https://www.sound-au.com/articles/reverb.htm

Front page of ESP is here;
https://www.sound-au.com/index.html

This would have to be one of the best web pages for DIY audio noobs who don't have the education,,and Very well written.
Phil.

tome.talevski · Post by **tome.talevski** » 07 Apr 2021, 22:42

The G wrote: ↑05 Apr 2021, 01:35 Here is the ugliest vero you'll ever see .
I was curious how hard it is to make a vero for a complete circuit. Well it is really hard, at least for me. I'm not seeing myself using veroboard for anything with more than 20 parts, ever.
This mod makes use of the op amp buffers to isolate the circuit blocks. It is also possible to use the inverted output, if one feels like it.
Let me know if you find issues.

wow! thanks so much.. when I eventually get around to this build ill report back.

Surfy Bear - Reverb [traced]