DE-3 Bristol Bloodhound MkI -Sine osc with wave mult

[Ravenware]

I hope it is ok that we share this on the thonk page?

Always OK to link or share!

[Jonachi]

Thanks! Looking forward to the Bunker video!

[Jonachi]

Also: It doesnt track the Bristol Scale (lots of people asking).

[Jonachi]

Thonk sale right now! Deep preice cut on Bristol.

https://www.thonk.co.uk/shop/de-bristol-bloodhound/

[dannyh]

Sorry, hoping somebody might have a clue as to what I've done wrong. I built the Bristol Bloodhound from the Thonk kit and can't seem to get it to work. I'm not getting any signal coming out of the sine output, and the only way to produce any sounds is to set the lfo switch down, send a constant cv signal into the frequency input, and then slowly turn the large knob until it hits the "sweet spot". But even then, it's only static feedback. If I change what the CV in pitch is, the sound goes away and I have to find another "sweet spot" to produce the same results.

Here is a temporary unlisted YouTube video of what is happening. I'll be deleting it once I figure out what I did wrong. At about 28 seconds in the video, I change the pitch from C3 to D3. Any help on this would be greatly appreciated. I did double-check that the power, PSY, and cable are all working properly with other modules, so that can't be the issue. I also double-checked to make sure there were no solder bridges happening.

[Jonachi]

hmmm there is something really wrong with the oscillator section for sure, hard to know what it can be witout you posting some hi-res photos of your soldering. Also please check and doublecheck IC's are put in correctly (according to the sil screen), also check that the TL074's are receivein + and - 12v at the correct pins.

[Jonachi]

Also check the jack board as well, for solder bridges on pots and headers. Is the wavemult working as should?

[dannyh]

Also check the jack board as well, for solder bridges on pots and headers. Is the wavemult working as should?

I doublechecked things and can't seem to find any solder bridges or misplaced ICs. For the wavemult, it doesn't seem to be working either, but I am getting some kind of static noise from it. Maybe it's partially working? I can re-test the wavemult later this week.

Here is a Drive folder with some very close-up images and a few not so close images of the boards. Hopefully whatever mistake I made is visible:

https://drive.google.com/drive/folders/ ... share_link

I have quite some TL072 and TL074s on hand, but not a CA0303 or AS2164, if they need to be replaced. Thonk and Ali have them so it's obtainable if necessary.

Thanks,

Danny

[Jonachi]

'thanks, cant spot anything wierd in your pictures.

The wavemult is easy to test since it can be operated completely independent by pugging in an external signal into its input. Maybe that is what you meant? The osc sine is normalled to that jack. If it works you dont need to replace

I've had more than one 2164 break on me, once in this build and several times in other builds. It seems to be somewhat touchy. If it is not working the complete osc section wont work at all. What you describe might be that is malfunctioning. But as I said, test the wavemult section first and make sure if it is working or now.

[dannyh]

'thanks, cant spot anything wierd in your pictures.

The wavemult is easy to test since it can be operated completely independent by pugging in an external signal into its input. Maybe that is what you meant? The osc sine is normalled to that jack. If it works you dont need to replace

I've had more than one 2164 break on me, once in this build and several times in other builds. It seems to be somewhat touchy. If it is not working the complete osc section wont work at all. What you describe might be that is malfunctioning. But as I said, test the wavemult section first and make sure if it is working or now.

Sorry for the delay, things got pretty hectic in the lab last week. I just tested the wavemult and it seems to be working well. So would this mean that most likely it is the 2164 that needs replaced?

[Jonachi]

It seems likely but hard to tell. You should try that along with the other things I listed above. Also the TL074's are crucial parts and easier to find and replace.

[dannyh]

It seems likely but hard to tell. You should try that along with the other things I listed above. Also the TL074's are crucial parts and easier to find and replace.

I just got the replacement AS2164s and that did the trick. It all seems to be working wonderfully now. Thanks for the support.

[Jonachi]

Awesome way to start the new year!

[Jonachi]

just a few left of the through hole version over at thonk. When they are gone it will be discontinued.

[Jonachi]

Sold out and discontinued. Might do another 1v/tracking oscillator in the future. Thanks to everyone who bought this.