hi Fuzzhead! I'm intrigued... Maby you can enlight me. It doesn't work. But I don't think it's an error on the layout. The layout is faithful to the schematic,as far as I can see. Somehow I suspect the schematic is not a proper one. 1. The LM7905 is a -5v regulator. The PT2399 works on +5v. The pinout of the regulator on the schematic shows a L7805, wich is a +5 regulator and the one who used to be associated with PT2399. Still they name it LM7905. Could be a typo? As it is it will simple blows the 10 ohm resistor and get hot as hell. I test it.It smokes. 2. A inductor on a delay? WTF... And a big one. Makes sense? 3.Anyway , I try the stuff with L7805... It doesn't blow anything, makes sound, no delay (yet the pots do their job), but you have fantastic noise and a delightful kind of motorboarding (all this well under the unity). All this with pot control. 4. So, my guess is this schematic goes nowere.
PS: As I don't have at the moment a 100mH inductor, so I used a 86 mH one. But i will try with the 100mH, before I desmantle the f*** useless thing.
Yes, initially I thought the LM7905 was a typo and it maybe is. The thing is that all PT2399 based Hagerman circuits has a LM7905 in their schematics like the Chorus/Vibe and the Tremolo. They may have typos as well? As you says, it makes no sense having a power regulator for negative voltage in a postive voltage circuit but maybe I've missed something.
Yes! An inductor in the feedback path. It might saturate the signal when the Repeat control is set high. Cool idea!
When you tried a 7805 regulator, did you twist the legs since 7805 has a IGO pinout?
Yes, I twist it. I'm good on twisting things. :O) And, as I said above, it worked. But not with the desired results... Glad about the inductor. Nothing against inductors.They're not in my blacklist. I'll throw a 100mH in, once I get one. And then we'll see. But I'm not having great hopes... Not going to loose more time with it. It was most curiosity about the inductor. Cheers, mate! And thanks for your answear.
Ok... Now with the 100mH indutor. Same thing as the other ones. So I rest my case. And I even try 4 diferent Pt2399. Calling the demolition man!... :O)
Iep, it matches absolutely. And it's a small and simple delay. Checked and triple checked (and build it two times). Some other fellow could try. Maby he'll get better luck than me. With these things you never know for totaly sure.
Just to make justice to this one... Last report: it´s verified now. With the following corrections: 1. Indeed, it'a a L7805 and not a L7905, on the regulator. 2. There's an error on the layout: the 4K7 resistor (that links to 100nF, on the output) should connect on H/13, and not on D/11, as it is. Other from that, the layout is perfect, and the delay sounds great. Think at "wicked game" guitar. Very crystal clean. It looks like the inductor is a winner. Last warning: careful with the L78L05 pinout. ST electronics ones are reverse to the other. That first induce me in error.
Hi Fuzzhead. For shure the regulator is a 7808. I even build the Hagerman Chorus (improvised myself the layout), and it works great...with the 7808! So definitly it's a typo on Hagerman site. At least for all Pt2399 pedals. By the way, the Chorus with that OTA IC it's far from bad. An interesting fellow if you ask me.
what an interesting thread! thank you, dragão for your time, persistence, and innovation! :) and thank you, fuzzhead for bringing this UP, in the first place :)
Got this half-working. I get a nice delay until I turn the repeats knob past 12 o'clock. Then I get self-oscillating white noise. Voltages around the PT2399 and regulator seems to be ok. Knifed between the copper strips thoroughly and tried different PT2399's. Any idea what to do next?
hi Fuzzhead!
ReplyDeleteI'm intrigued... Maby you can enlight me. It doesn't work. But I don't think it's an error on the layout. The layout is faithful to the schematic,as far as I can see. Somehow I suspect the schematic is not a proper one.
1. The LM7905 is a -5v regulator. The PT2399 works on +5v. The pinout of the regulator on the schematic shows a L7805, wich is a +5 regulator and the one who used to be associated with PT2399. Still they name it LM7905. Could be a typo? As it is it will simple blows the 10 ohm resistor and get hot as hell. I test it.It smokes.
2. A inductor on a delay? WTF... And a big one. Makes sense?
3.Anyway , I try the stuff with L7805... It doesn't blow anything, makes sound, no delay (yet the pots do their job), but you have fantastic noise and a delightful kind of motorboarding (all this well under the unity). All this with pot control.
4. So, my guess is this schematic goes nowere.
PS: As I don't have at the moment a 100mH inductor, so I used a 86 mH one. But i will try with the 100mH, before I desmantle the f*** useless thing.
Yes, initially I thought the LM7905 was a typo and it maybe is. The thing is that all PT2399 based Hagerman circuits has a LM7905 in their schematics like the Chorus/Vibe and the Tremolo. They may have typos as well?
DeleteAs you says, it makes no sense having a power regulator for negative voltage in a postive voltage circuit but maybe I've missed something.
Yes! An inductor in the feedback path. It might saturate the signal when the Repeat control is set high. Cool idea!
When you tried a 7805 regulator, did you twist the legs since 7805 has a IGO pinout?
This comment has been removed by the author.
DeleteYes, I twist it. I'm good on twisting things. :O)
DeleteAnd, as I said above, it worked. But not with the desired results...
Glad about the inductor. Nothing against inductors.They're not in my blacklist.
I'll throw a 100mH in, once I get one. And then we'll see. But I'm not having great hopes... Not going to loose more time with it. It was most curiosity about the inductor.
Cheers, mate! And thanks for your answear.
Ok... Now with the 100mH indutor. Same thing as the other ones. So I rest my case. And I even try 4 diferent Pt2399. Calling the demolition man!... :O)
ReplyDeleteBummer! Thanks for giving this one a go. I will mark this "On Hold" since it matches the schematic.:-/
DeleteIep, it matches absolutely. And it's a small and simple delay. Checked and triple checked (and build it two times). Some other fellow could try. Maby he'll get better luck than me. With these things you never know for totaly sure.
DeleteThat's a shame☹️
ReplyDeletePt2399 delays are my favourite. The size of the boards is still too intimidating for me.
Maybe one day...
Just to make justice to this one...
ReplyDeleteLast report: it´s verified now.
With the following corrections:
1. Indeed, it'a a L7805 and not a L7905, on the regulator.
2. There's an error on the layout: the 4K7 resistor (that links to 100nF, on the output) should connect on H/13, and not on D/11, as it is.
Other from that, the layout is perfect, and the delay sounds great. Think at "wicked game" guitar. Very crystal clean. It looks like the inductor is a winner.
Last warning: careful with the L78L05 pinout. ST electronics ones are reverse to the other. That first induce me in error.
Nice!
DeleteI mean, D/16 when I write D/11 out there... Sorry for the typo.
ReplyDeleteThanks for solving this one Dragao. The layout is updated using a 7805 regulator and the 4,7k/470k/100nF output section is fixed.
DeleteHi Fuzzhead. For shure the regulator is a 7808. I even build the Hagerman Chorus (improvised myself the layout), and it works great...with the 7808!
ReplyDeleteSo definitly it's a typo on Hagerman site. At least for all Pt2399 pedals.
By the way, the Chorus with that OTA IC it's far from bad. An interesting fellow if you ask me.
what an interesting thread!
ReplyDeletethank you, dragão for your time, persistence, and innovation! :)
and thank you, fuzzhead for bringing this UP, in the first place :)
this is a precious one
Hey, stupid typo of me up there. Were is 7808, you should read 7805, obviously.
ReplyDeleteGot this half-working. I get a nice delay until I turn the repeats knob past 12 o'clock. Then I get self-oscillating white noise. Voltages around the PT2399 and regulator seems to be ok. Knifed between the copper strips thoroughly and tried different PT2399's. Any idea what to do next?
ReplyDeleteAnyway, thank you fuzzhead for posting this!
Hello Fuzzhead, thanks for your designs, could I ask you for this one please?https://www.diystompboxes.com/smfforum/index.php?topic=114973.0
ReplyDelete