Scott Hampton Class A Opto Comp with schemo and parts list!

[Ptownkid]

[quote author="matta"]Thanks Ptown,

I'm a newbie board etcher... got to start somewhere ;-)
Have you started on your yet?

Cheers

Matt[/quote]

No, i haven't yet, but I've etched tons of boards. Hell, i've even done some hand drawn with a sharpie and they work great, even if they look ugly.

 

[Sleeper]

Hey this looks like a good one. I'm thinking this will happily mate up with some hamptone jfet opamps that i have... all the same transistors etc which is nice. I think I'll etch these up very soon.

I have a question for Ptown.

What is the actual size on your board?
I think I'm having some graphics import issues...

Thanks.
Sleeper.

 

[Ptownkid]

The overall dimensions should be 1.82" x 2.7"

 

[Sleeper]

Hey Thanks for that.
Looks like I might etch this to etch this tonight. :grin:

I'm considering a switch for ratios.

Guess we'll have to check it out with a pot first and then find some values that work.
I don't know when I'll get to this, I haven't even ordered the optos yet, but I'll paste this down for my own reference (or someone elses if they'd like to give it a shot)

here's how SSLtech does it.

Set the threshold so that there's about 8dB of compression. Set the make-up gain to read a known figure... perhaps 0dB on whatever scale you choose. Then increase the input by a calibrated amount... I suggest 10dB. At 2:1 compresion, the output should increase by 5dB for a 10dB input increase. -starting with a goodly amount of GR at the baseline measurement before you increase the input signal will make sure that you're away from the 'knee'.

For each ratio measurement, re-check your baseline level and re-adjust the makeup gain to get you to a convenient point, if necessary.

Anyhow, PTown, thanks again.
Sleeper

 

[dayvel]

[quote author="craigb"]re: opto slopes

I've been fooling around with a stereo opto-comp circuit using VTL5C2's for some time.

[/quote]

I picked up a bunch of these from BG Micro a while back and would love to see what you've come up with.

 

[Ptownkid]

On the bom there are a few resistors with no k after them, are they in ohms?

 

[matta]

Hey Ptown,

I can only assume they are R (Ohm?s). They are not designated on Scott?s
Schemo, nor in the parts list I have seen, through the K ohm?s are, so an
educated guess would be that they are R, all I can offer right now. I?ll see
if I can?t confirm it, but I?m pretty sure they are R.

How is yours coming along? Are you stuffing your board already?

Cheers

Matt

 

[Ptownkid]

Etching the boards as we speak

have to order some parts online as I could not find them locally

Should have it together by mid next week

 

[kvintus]

Should have it together by mid next week

So? What happened? Did it blow up or is it your new secret weapon in the studio?

Tell us!

/A

 

[Ptownkid]

Well.......

unfortunately, two of the parts are "special order" for newark, and they seem to be the only place that I can gett all 4 remaining parts that I need at once.

Seems like a huge waste to order $3 worth of parts from mouser and pay $12 for shipping, retarded....

I'll post the secong it's done.

 

[jetboatguy]

I've been looking for these type of enclosres... I don't even now what they are called or where to buy ?

Anyboby...???

 

[jetboatguy]

I just found a similar enclosure for a muti channel unit...


http://www.paia.com/fracrak.htm

 

[matta]

Hi Guys,

Thanks to Ziess I've added a .PDF version of my BOM, which can be found here:

http://www.matt-allison.com/diy/HamptoneCompBOM.pdf

Did anyone ever build one these units? I'd be interested to here your comments.

Cheers

Matt

 

[classAdiscrete]

for the enclosure try mouser...catalog page 1384 vector brand

574-CMA13-20--- module sub rack
574-EFP204A66 ---
574-EFP164A66 ---modules

mike

 

[jeroddumas]

Anyone finished this yet. I have all parts on order and ready to etch the board. Any thought?

 

[jeroddumas]

I finished the comp a couple days back. It is very usable. The sound is not colored from what I have the materail I have tested it with. I am going to mount it in a cheap rat shack enclosure. Pics then. Anyone else built this?

 

[fucanay]

These enclosures look identical to the one Craig Anderton used in the book "Electronics Projects for Musicians". I would be cool to get some like that if they were cheap.

Matt

 

[theom]

I'm new here so forgive me:

This appears to be a unballanced circuit. How hard would it be to add some tasty trannys to this design? Without modification to the pcb?

 

[Guest]

The modules Scott used appear to be similar to the Vector Electronics EFP DIN series modules here: http://www.vectorelect.com/Product/Subracks/EFP-Module.htm
They sell these at Mouser, Digikey and Allied. For example: http://www.mouser.com/catalog/624/1384.pdf
The only problem is that they are so damn expensive. $164 US for the chassis and $31.29 US for each of the 1.6" modules. It's cheaper to stick with Par-Metal racks for now.

Cheers,

elco

 

[kiira]

[quote author="fucanay"]These enclosures look identical to the one Craig Anderton used in the book "Electronics Projects for Musicians". I would be cool to get some like that if they were cheap.

Matt[/quote]

Have you seen this?

http://www.paia.com/fracrak.htm

The rack is 33$ and the front module plates are $3.50. Paia also sells bipolar 15V amd 18 V. PSs for them too which don't take up a rack space. They are alos anadized already. I dunno... they are a lot cheaper than anything else Iv'e seen though not as zoot with full enclosed boxes and all that.

Kiira