Thanks!caprotesta wrote:I'm curious about D2. Previous posts have said that this is a ZPY diode. Looking at the picture, it looks like Zener diode, but does anybody know what value it is?
Thank you.
Mesa Boogie - Throttle Box [schematic]
Information
Hey guys! I just finished some PCBs for the project. Works amazing! One of the best High gain Drives I've ever tried.
I have some extra boards if someone is looking to build this project, I'll let them go for cheap cause they were made as prototypes, still a couple of things to correct and improve!
And here a video of my build
https://pcbguitarmania.com/wp-content/u ... roject.mp4
I have some extra boards if someone is looking to build this project, I'll let them go for cheap cause they were made as prototypes, still a couple of things to correct and improve!
And here a video of my build
https://pcbguitarmania.com/wp-content/u ... roject.mp4
- caspercody
- Resistor Ronker
Sego91
I ordered your Throttle box PCB, along with a Green Screamer back on 11/07. I have not received them, nor have I gotten any return emails with tracking information??
So I thought I would try on here, since I saw you were just on here.
Thanks
Rob
I ordered your Throttle box PCB, along with a Green Screamer back on 11/07. I have not received them, nor have I gotten any return emails with tracking information??
So I thought I would try on here, since I saw you were just on here.
Thanks
Rob
- caspercody
- Resistor Ronker
Deleted
- jhergonz
- Breadboard Brother
still can't understand why the c19 must be connected to ground if the circuit is bypassed ... , can anybody explain? please?
- Dirk_Hendrik
- Old Solderhand
Information
C19 has been raised a few times in this thread and the question is not solved.
In my opinion, when a gain pedal is bypassed, the (input of the) circuit should be tamed so it will not go into oscillations, buzzing noises or whatever else. That means that one would want to reduce the gain in such an occasion. When "grounding" the inverting input of the opamp like this the gain of that amplifier stage goes through the roof, (either 390k or 47k divided by the impedance of C19 plus 1) and the higher the frequency, the higher the gain. I cannot imagine this cap is correct in this application and either Mesa or Apollo missed something.
In my opinion, when a gain pedal is bypassed, the (input of the) circuit should be tamed so it will not go into oscillations, buzzing noises or whatever else. That means that one would want to reduce the gain in such an occasion. When "grounding" the inverting input of the opamp like this the gain of that amplifier stage goes through the roof, (either 390k or 47k divided by the impedance of C19 plus 1) and the higher the frequency, the higher the gain. I cannot imagine this cap is correct in this application and either Mesa or Apollo missed something.
- Dirk_Hendrik
- Old Solderhand
Information
- caspercody
- Resistor Ronker
- caspercody
- Resistor Ronker
caspercody wrote:I used this one from Mouser, It is the same one in the picture of the board a couple of posts up from sego91.
https://www.mouser.com/ProductDetail/wu ... cycode=USD
- caspercody
- Resistor Ronker
Thanks for pointing that out!
I just tried the pedal again, and the mid cut pot does nothing. The mid cut switch actually cuts the column down a lot.
How about this:
https://www.taydaelectronics.com/0-22uh ... -ec24.html
I just tried the pedal again, and the mid cut pot does nothing. The mid cut switch actually cuts the column down a lot.
How about this:
https://www.taydaelectronics.com/0-22uh ... -ec24.html
- marshmellow
- Cap Cooler
No, µH again. I used these once for a passive tube EQ, they sold directly from the company.
Alternatively, put these two in series (L1, L2). But they have rather high DC resistance, I would leave out R17.
Another option: get this core, wind 270 turns of 0,16mm (34 AWG).
Or as Dirk suggested, ask Flo, I am sure his inductor would werk very well.
Alternatively, put these two in series (L1, L2). But they have rather high DC resistance, I would leave out R17.
Another option: get this core, wind 270 turns of 0,16mm (34 AWG).
Or as Dirk suggested, ask Flo, I am sure his inductor would werk very well.
Does anyone have the redemptive answer regarding the position of capacitor C19? According to several people on this forum, there would be an error in the schematic regarding this capacitor. Are there people who have built the pedal themselves and can confirm that this is indeed wrong?
Are there any other people who have gut shots of the traces on the PCB? Then we know for sure if this is correct in the schematic.
Are there any other people who have gut shots of the traces on the PCB? Then we know for sure if this is correct in the schematic.
- FloPoeKo
- Breadboard Brother
On the Inductor:
Are we 100% sure it is 250mH and not 220mH? The coil in the pictures pretty much looks like the ones they put in the amp-eq-sections, and there, they use 220mH for the 750Hz-Slider... The whole thing actually pretty much looks like a small, if a tad different, version of exactly this slider...
Any thoughts?
Are we 100% sure it is 250mH and not 220mH? The coil in the pictures pretty much looks like the ones they put in the amp-eq-sections, and there, they use 220mH for the 750Hz-Slider... The whole thing actually pretty much looks like a small, if a tad different, version of exactly this slider...
Any thoughts?
- Attachments
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- Mesa EQ.tiff (92.62 KiB) Viewed 3958 times
- FloPoeKo
- Breadboard Brother
Afterthought:
Does any one have a clue wether the DC-Resistance of the Inductor will be of any concern in this circuit?
If so, has anyone measured the original inductor for Inductance and DC Resistance?
I know a both are frequency-dependent, but this would help get things in the ballpark since we all use cheap RLC-Meters that measure at 1kHz and I think a have a stash of very small coils somewhere that should fit the pcb and (!) deliver the 250mH with a reasonably low DC-resistance (which I might be able to get wound to my usual ±2% tolerance)...
Does any one have a clue wether the DC-Resistance of the Inductor will be of any concern in this circuit?
If so, has anyone measured the original inductor for Inductance and DC Resistance?
I know a both are frequency-dependent, but this would help get things in the ballpark since we all use cheap RLC-Meters that measure at 1kHz and I think a have a stash of very small coils somewhere that should fit the pcb and (!) deliver the 250mH with a reasonably low DC-resistance (which I might be able to get wound to my usual ±2% tolerance)...
- temol
- Solder Soldier
here is a plot from ltspice simulation. With 250mH you have 678 Hz, with 220mH - 720 Hz and with 200mH - 760 Hz.FloPoeKo wrote:On the Inductor:
Are we 100% sure it is 250mH and not 220mH?
T.