How to increase feedback on a Deep Blue Delay

[Hardos174]

Hi,

I'm new on diystompboxes and this is my first post.

I've got a stupid question as I'm not an expert in electronic, I can build pedal and tube amps but I don't really understand how the components works together and why... So I would like to know how I can increase my feedback on a Deep Blue Delay I've builded??
It works but I think with the tolerance of some resistors or something like that I haven't got the same number of repeats than my previous DBD...! The difference is not enormous but I would like to increase the feedback a little bit.
I think there is several resistors around the pt2399 which are responsible of the feedback...!? But which one and which value I need to put, that's my question!

Hope somebody will be kind enough to help me a little... And I'm really sorry for my rotten English, I hope I'm understandable! ;-)
Thanks in advance.

Alex.

[mcknib]

You could try lowering the fixed 2K resistor going to lug 2 of the repeats pot to 1K or lower - if it's infinite repeats you're looking for.

The resistor from the repeats / feedback pot lug 2 to the Mix / Level pot lug 3, I think it is looking at a DBD schematic it's 2K anyway.

[midwayfair]

I think you've got something wrong if you're not getting oscillation around 2:00-3:00. Especially because you say the difference is "enormous." Unless your resistors are 500% tolerance, it should oscillate like crazy with the repeats pot wide open.

[Hardos174]

Thanks for your help!

I will try to change the resistor value as you said...

And I said the difference is NOT enormous in comparison to the previous DBD I've made! So I think it can come from the resistors I used because for this build I've used 5% resistors instead of the 1% I use usually...

But I will try what you said today and I'll tell you if it's ok!!
Thanks for all!

Alex.

[mcknib]

5% or 1% won't make much difference Alex if you want more repeats try changing that resistor, socket it and try different values until you get the number of repeats you want

You've also got to take into account that the PT2399 isn't a hi fi device so it could be that causing the slight difference between builds

[Hardos174]

Hi,

I've made the mod you told me and all is perfect!!
You're AWESOME!!
One more time thanks for all!!!