Hagerman Amplification (schematics)

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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Agent86
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Post by Agent86 »

Hagerman Amplification posts schematics with each pedaLs

https://www.hagamps.com/collections/silicon

thank you mr. Hagerman!

:applause:

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stolen
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Post by stolen »

Good move, and reasonable prices. We appreciate. Thanks for sharing!

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turbofeedus
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Post by turbofeedus »

I was wondering when I was going to see someone using those hammond flanged enclosures

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Frank_NH
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Post by Frank_NH »

That fuzz sounds great! Bravo.

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ppluis0
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Post by ppluis0 »

Hi Pals,

Nice detail from this builder as publish schematics of their entire line of products. 8)

This person also makes some tube pedals and I would like to discuss the operation of a compressor (whose diagram appears in the manual for that product.)

It is not clear to me how the sidechain works... :hmmm:

https://www.hagamps.com/collections/ped ... compressor

Cheers,
Jose

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caspercody
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Post by caspercody »

Thanks for this!

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287m
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Post by 287m »

Thanks Agent86 and of course Mr Jim Hagerman.

Done 4 perf layout for masochist 1590B top jack. I DO like standard values, so easily available.

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stolen
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Post by stolen »

ppluis0 wrote: 22 Jul 2021, 19:16 I would like to discuss the operation of a compressor
Hi Jose, we'd be interested in that too! It's a peculiar setup, with the sorta-kinda long-tailed pair. Just ran the numbers in our head, we're not quite sure what the advantage of that is either, but there might be something interesting hidden in there! Need to do this properly on paper later to make sure we're not missing anything. Also optical feedforward compressors are super rare, we wonder if/how they match gain cell performance as would be recommended in such a design.

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ppluis0
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Post by ppluis0 »

Hi stolen,

I think that since this manufacturer is open minded enough to share their product diagrams maybe we can ask for some additional explanation.

I believe that the transistor on the right should be used to compensate for fluctuations due to temperature or very slow changes, and the one on the left receives the audio signal to turn on the led.

It would be interesting to know what hfe value these transistors will have and what kind of optocoupler this equipment is using.

My scope of the English language is quite limited so if any member of the forum would like to contact Mr. Hagerman ( jim@hagamps.com ) and see what he can tell us to learn more about this circuit, it would be appreciated.

Cheers,
Jose

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stolen
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Post by stolen »

Hi Jose,

we might, but frankly we're more into the idea of figuring it out on our own :D. Also they might be more open to communication if we put a bit of legwork in ourselves first.

Also oh dear you're right. We imagined a diode in front of R24 to turn it into a peak detector that wasn't there, and based our thoughts on that. New brain bug, interesting :D! Thanks for poking.

Temperature compensation is an interesting thought, but since Q3 operates with feedback via R28 it would compensate for the temperature effects on the LED junction itself. From what we know this is wavelength dependent, at constant current brightness drops with rising temperature, but we don't know there are reliable parameters across instances.

Honestly we're not even sure if DC gets properly cancelled to begin with - gosh we're bad at figuring this out just by staring at it. In an exciting way :3.

Unrelated: They are using a Norton amp in their distortion pedal. Interesting. From what we know they are just hard clippers with relatively unspectacular side effects, and the sound sample does not contradict this notion, but maybe somebody knows more about that or has seen other circuits?

Will do sidechain math when at home. Looking forward to it. Good snacc for brain goo.

Cheers,
stolen

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