Mesa Boogie - Throttle Box  [schematic]

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Re: Mesa Boogie - Throttle Box

Postby ferhdas » 27 Nov 2016, 04:21

Hi guys,
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.


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Re: Mesa Boogie - Throttle Box

Postby askwho69 » 08 Dec 2016, 13:51

Hi does anyone sellibg PCB on this? I know this thread is old but, maybe someone has extra pcb on this. :scratch:
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Re: Mesa Boogie - Throttle Box

Postby juan_felt » 09 May 2017, 20:12

Hi,

One question, if I wanted to add a 3 band eq to this pedal instead of the tone and mids switch, where in the circuit should I do this?
I'd like to use a 3 band baxandall I already (succesfully) used in a BSIAB.

Thanks!
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Re: Mesa Boogie - Throttle Box

Postby ballfire » 11 Dec 2017, 04:21

hello..

its ok not to use the inductor on this pedal?? cause i dont have a inductor here..

thanks
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Re: Mesa Boogie - Throttle Box

Postby sego91 » 09 Apr 2018, 12:54

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! :D



Image

Image

And here a video of my build :)

https://pcbguitarmania.com/wp-content/uploads/2018/03/mesa-project.mp4

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Re: Mesa Boogie - Throttle Box

Postby caspercody » 02 Dec 2018, 01:00

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
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Re: Mesa Boogie - Throttle Box

Postby caspercody » 02 Dec 2018, 16:08

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Re: Mesa Boogie - Throttle Box

Postby jhergonz » 10 Dec 2018, 05:02

still can't understand why the c19 must be connected to ground if the circuit is bypassed ... :scratch: :scratch: :scratch: :hmmm: , can anybody explain? please?
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Re: Mesa Boogie - Throttle Box

Postby Dirk_Hendrik » 11 Dec 2018, 11:49

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.
Sorry. Plain out of planes.

http://www.dirk-hendrik.com
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Re: Mesa Boogie - Throttle Box

Postby teddeeh » 15 Dec 2018, 08:14

Hey guys. Where the hell can i get the bloody inductor from? Does it have to be exact values aswell or can a similar value be used?
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Re: Mesa Boogie - Throttle Box

Postby Dirk_Hendrik » 15 Dec 2018, 10:00

Sorry. Plain out of planes.

http://www.dirk-hendrik.com

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Re: Mesa Boogie - Throttle Box

Postby caspercody » 16 Dec 2018, 05:31

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Re: Mesa Boogie - Throttle Box

Postby caspercody » 16 Dec 2018, 05:33

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
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Re: Mesa Boogie - Throttle Box

Postby temol » 16 Dec 2018, 09:42

caspercody - value of the inductor should be in mH, not uH (Milihenr vs Microhenr). So 220mH would be probably ok, but 220uH is way off.

T.
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Re: Mesa Boogie - Throttle Box

Postby caspercody » 16 Dec 2018, 18:45

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
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Re: Mesa Boogie - Throttle Box

Postby marshmellow » 16 Dec 2018, 20:20

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.

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Re: Mesa Boogie - Throttle Box

Postby Ricotjuh » 03 Jan 2019, 15:22

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.
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Re: Mesa Boogie - Throttle Box

Postby FloPoeKo » 08 Jan 2019, 11:35

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?
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Re: Mesa Boogie - Throttle Box

Postby FloPoeKo » 08 Jan 2019, 11:48

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)...
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Re: Mesa Boogie - Throttle Box

Postby temol » 08 Jan 2019, 12:39

FloPoeKo wrote:On the Inductor:

Are we 100% sure it is 250mH and not 220mH?


here is a plot from ltspice simulation. With 250mH you have 678 Hz, with 220mH - 720 Hz and with 200mH - 760 Hz.

Lsweep.jpg

T.
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