IN PROGRESS Hudson Sidecar

M

manfesto

Well-known member
Just built the EffectsLayouts Adjunct and, as somebody who isn’t a huge fan of TubeScreamers, it may be the best-sounding take on the circuit I’ve ever played; still plenty of spank but a *much* larger gain range (definitely gets near-fuzzy at max), a well-tuned 2-band bax EQ, and an unusual-but-pleasing clipping characteristic - you can tell it’s asymmetrical but not to the point of harshness or crunchiness.

The op-amp, LM4562, isn’t a common one for pedals but isn’t unobtanium to source (and can be subbed for any of the usuals).

the old wishlist had gutshots of this pedal if I remember correctly
 
Upvote 22
That's a good point.

I didn't use the Adjunct schematic for reference but I have two schematics, one lists B5K, the other B25K.

The Hudson website also states that the Sidecar uses a pair of germanium diodes, where the traced unit(s) had a single Ge transistor used as a diode. There was also a bit of confusion about which PN junction was used, B/E or B/C. Either work fine, B/E has a slightly higher forward voltage drop.

I'm debating grabbing an original just to confirm. I hate all of these unknowns.... although the prototype sounded fantastic.
 
Robert said:
That's a good point.

I didn't use the Adjunct schematic for reference but I have two schematics, one lists B5K, the other B25K.

The Hudson website also states that the Sidecar uses a pair of germanium diodes, where the traced unit(s) had a single Ge transistor used as a diode. There was also a bit of confusion about which PN junction was used, B/E or B/C. Either work fine, B/E has a slightly higher forward voltage drop.

I'm debating grabbing an original just to confirm. I hate all of these unknowns.... although the prototype sounded fantastic.
Click to expand...
Looks like the description's changed over time, in 2019 it was "Selected NOS Germanium Diode":

SIDECAR – HUDSON ELECTRONICS UK

Our take on the classic 808 circuit with the added versatility of a powerful two-band EQ which draws inspiration from a vintage Studer recording console. Packed with attitude and full of character, the Sidecar can cover classic overdrive and distortion as well as, at extreme settings, fuzz and...
web.archive.org web.archive.org

But changed to "A pair of Germanium diodes" in 2020:

SIDECAR – HUDSON ELECTRONICS UK

Our take on the classic 808 circuit with the added versatility of a powerful two-band EQ which draws inspiration from a vintage Studer recording console. Packed with attitude and full of character, the Sidecar can cover classic overdrive and distortion as well as, at extreme settings, fuzz and...
web.archive.org web.archive.org

So odds are the traces are of the 2019 model maybe?
 
Just for shiggles, while waiting on a fresh trace, any chance someone with LTSpice could simulate the Tone Stack section of the circuit? None of the online TSCs I can find look quite like the one from the Sidecar schematic unfortunately, but from this chunk of the circuit description:

"BASS – Adjusts the low end content of the signal, +/- 15 dB at 85 Hz (shelving).

TREBLE – Adjusts the high end content of the signal, +/- 15 dB at 8800 Hz (shelving)."

Should be able to plug in 5K and then 25K for the treble pot and see which value gives 15dB of boost/cut
 
OK, got some pics of the new version. Not entirely sure what the diodes are, and I see a few component values different from the older trace....
So, new version is incoming.

Meanwhile, I'm also waiting to hear back from a friend with the older stripboard version who might can answer some questions about what is in his.
 
Robert said:
I swapped the B25K for B5K and can't say I hear a world of difference.

Of course it's hard to distinguish any subtleties since I couldn't quickly A/B between them, but neither sounded obviously "off" .
Click to expand...
Wondering if maybe that was part of the circuit revision at some point too, would explain the different schematics, maybe Hudson figured out a 25K sounded basically the same so why not switch to it, one less weird value pot to stock up on?

From @temol ’s simulations it looks like they’re within 1-2 dB of each other
 
Robert said:
I swapped the B25K for B5K and can't say I hear a world of difference.

Of course it's hard to distinguish any subtleties since I couldn't quickly A/B between them...
Click to expand...

If only PedalPCB had a pot-swapper utility board...

funny-winking-kitten-picture-id1267021092
 
I did the original trace. I didn't "do" the stripboard layout (I hate stripboard); it was a transcription of the stripboard chunk in the actual pedal. It's a bit crazy-making to see people debating which values are the correct ones when the designer clearly just throws in whatever he has lying around. There is no one definitive version.

As far as I can tell, all the layouts and schematics out there are based on mine. If they differ, it's either a transcription error, a deliberate change to match a different gutshot they saw somewhere else, or a correction to my original schematic where I may have made an error with regards to the gutshots I was working from. If you want to do your own trace or verify mine, they're right here. Mystery solved.
 
You must log in or register to reply here.
Back
Top