Zero Point DD too loud

[Manc]

Hi folks,

I finished a Zero Point DD and it works a treat, only its output is way too hot...
When I tested it (ok it was late at night) my amp volume was really really dimed, and the repeats were ok, so I thought it was fine....
It is now boxed and all, but it does bug me.
The only sub I made war R28, where I used a 680R instead of the listed 620R.

I'm now considering to hook a 100k pot to the output to tame it somehow, as it boosts my signal!
In fact is a perfect "solo pedal" now

Any ideas?

[midwayfair]

Are both the delay and dry signal above unity?

I'm not sure Brian's exact reasons for it, but in this design, the gain of the first op amp stage is 2x, and then the second stage is 1x, instead of the usual 0.5x. In any case, the easiest change is to drop R5 -- I'd socket it, then try 5.1K first and tweak from there.

[Manc]

Cheers Jon, I'll give it a shot!

[pickdropper]

I had the same issue with mine, so I socketed R5.  I also feel the non-delay signal is a bit bright, so I'm tinkering with that as well.

[Manc]

Right, I swapped R5 with a 5K1 resistor.
It works like a charm, cheers guys! (I don't feel it brightens the tone tho).

[Gledison]

I have a similar issue! Mine works as a booster! The thing is that it improves my tone amazingly!
I have no idea why, but i got a louder and bitty tone!
Cheers

[blearyeyes]

I had the same issue with mine, so I socketed R5.  I also feel the non-delay signal is a bit bright, so I'm tinkering with that as well.

I was a little disappointed in the difference between the tone of the direct and the repeats being so different. If you figure out a fix please post it..

[midwayfair]

I had the same issue with mine, so I socketed R5.  I also feel the non-delay signal is a bit bright, so I'm tinkering with that as well.

Do you want the delay to be brighter, or the dry to be darker?

The PT2399 chip has very poor bandwidth at times above 200mS and requires heavy filtering. It's also not particularly great at sounding like an exact copy even at very short delay times. The fidelity just isn't like higher end digital stuff.


I was a little disappointed in the difference between the tone of the direct and the repeats being so different. If you figure out a fix please post it..

[madbean]

I had the same issue with mine, so I socketed R5.  I also feel the non-delay signal is a bit bright, so I'm tinkering with that as well.

I was a little disappointed in the difference between the tone of the direct and the repeats being so different. If you figure out a fix please post it..

All the Zero Points are tweaked for filtered repeats. But, you can change this easily on the DD by removing or lowering C21. It has a big effect on the tone of the repeats. A small cap there is a good idea to keep noise down, though. Try 6n8 or 10n. Also, you can increase C22 to 220n which will give you a broader frequency range on the repeats.

As far as the clean through being too loud, reduce R3 to 470k. Looking back, this is a better choice and I should probably put a note in the project doc. Interestingly, I did not notice too much of a boost, but I also probably did not crank it much, either.

[pickdropper]

I had the same issue with mine, so I socketed R5.  I also feel the non-delay signal is a bit bright, so I'm tinkering with that as well.

Do you want the delay to be brighter, or the dry to be darker?

The PT2399 chip has very poor bandwidth at times above 200mS and requires heavy filtering. It's also not particularly great at sounding like an exact copy even at very short delay times. The fidelity just isn't like higher end digital stuff.


I was a little disappointed in the difference between the tone of the direct and the repeats being so different. If you figure out a fix please post it..

On my build, the dry signal had a bit of extra sparkle to it (which obviously is preferred by some).

I just haven't had time to dig into this lately.  The first step is to knock back the gain and see where things are at.

[blearyeyes]

All the Zero Points are tweaked for filtered repeats. But, you can change this easily on the DD by removing or lowering C21. It has a big effect on the tone of the repeats. A small cap there is a good idea to keep noise down, though. Try 6n8 or 10n. Also, you can increase C22 to 220n which will give you a broader frequency range on the repeats. As far as the clean through being too loud, reduce R3 to 470k. Looking back, this is a better choice and I should probably put a note in the project doc. Interestingly, I did not notice too much of a boost, but I also probably did not crank it much, either.

Is this only for the DD or is it applicable to the DLX as well ?

[blearyeyes]

Do you want the delay to be brighter, or the dry to be darker?

The PT2399 chip has very poor bandwidth at times above 200mS and requires heavy filtering. It's also not particularly great at sounding like an exact copy even at very short delay times. The fidelity just isn't like higher end digital stuff.

Probably a little of both. A bit less bright on the direct and what ever can be done with the PTs output to brighten and blend the two. Just two very different tones on my rig.

[lars]

I'm glad I'm not the only one who experienced the boost issue, I think in my case it is a voltage issue. When I first tried my build, I was just using a 9v battery. Everything sounded great! Once I switched to a wallwart though, my voltage input jumped to about 14v, so the PT2399's stayed at 5v, since they're regulated, but all the op-amps got a kick in the pants. Thanks for the advice at swapping out R3 from 1M to 470k, that should do the trick.
*update 8/21/14* The swap of R3 from 1M to 470k worked great. The volume is at unity with the clean signal, no more boost. I have to say at minimum delay with little to no feedback, this circuit does the best vintage slapback echo I've ever heard in a pedal.