[BUILd] PM660 / PM670 SCAmp Booster build and tips help thread

Help Support GroupDIY:

SUPERMAGOO

Well-known member
Joined
Mar 12, 2005
Messages
348
Location
argentina
do not worry about the hum!.
I just want to hear about how a strong
compression on rock-drums.
if necessary installing the power transformer in an external case.
 

Kingston

Well-known member
Joined
Nov 1, 2005
Messages
3,707
Location
Helsinki, Finland
lolo-m said:
I tried all the possibilities I had. Unregulated and regulated. Regulated was better but not perfect. The transformer is roughly used on filament PSU. We are pumping 5,2A constantly, and the caps haven't got enough guts to handle that. There is something like 2 or 3 volt sawtooth on the DC...
The drums sounsamples are made with a regulated PSU based on 2 LM350. I had to add a cap (330uF) to the adjust resistor and went with four 4700uF caps ( and not 2 ) to limit the oscilation. Of course, I played with the transformers place and put a metal shield between the toroid transformer and the electronics...
  And the hum is still here  :-\, small but here...

Interesting, did you use the Moby/silentarts regulator board, or rolled something of your own? Certainly using 5,2A of a 6A supply with filters is pushing it.

I haven't actually had my PSU toroid made yet, but I already specified it with 2X 9VAC 3A windings, for two separate rect/regulator/filters (pulling 2,6A each). I expect that would be easier on the transformer, compared to one BIG 6A winding... we'll see.
 

lolo-m

Well-known member
Joined
Dec 14, 2005
Messages
757
Location
Avignon, France
SUPERMAGOO said:
do not worry about the hum!.
I just want to hear about how a strong
compression on rock-drums.
if necessary installing the power transformer in an external case.
The drums samples were made with around 7 to 10 dB compression (depends of the network). I didn't change any setting (input and threshold), the only change is the type of TC network used, and of course the modes (analag's and SCAB)...
I did go up to 20dB compression without problem, the sound was still clean, but on SCAB mode the attacks were completely smashed and a huge pumping effect created... You have this pumping effect on the samples, but it's still musical.
Note: the ring of the drums is a lot more present and some details are appearing  :)...
 

lolo-m

Well-known member
Joined
Dec 14, 2005
Messages
757
Location
Avignon, France
radiance said:
Thanks for the samples Lolo. Are all files normalised? / Do all files have the same volume?
All the files are as they get out of the comp. No normalisation, no tricky thing. I also resample the file in bypass mode to be sure the AD/DA conversion to be on all files to compare  :). They are more or less the same volume but I cutted the end of the files after recording quickly, so they don't have exactly the same weight.
 

radiance

Well-known member
Joined
Jun 4, 2004
Messages
3,157
Location
the Netherlands
ok thanks...on my computer speakers the uncompressed file was rather loud in comparison to the compressed files.

Have not loaded them in my DAW yet...
 

lolo-m

Well-known member
Joined
Dec 14, 2005
Messages
757
Location
Avignon, France
It's possible there's some level changes between compressed and uncompressed files. I didn't bother levels  ;D...
 

Freddy G

Well-known member
Joined
Jun 4, 2004
Messages
463
Location
Canada
Does anyone have part numbers for the connectors shown in this photo? The green one as well as the white ones, and the female mates for the white ones too.  Having a heck of a time trying to find them, I don't know exactly what they're called! Mouser or digikey would be good...



proto2.jpg


Thanks ;)
 

idylldon

Well-known member
Joined
Jun 6, 2004
Messages
561
Location
Idyllwild, CA
Freddy G said:
Does anyone have part numbers for the connectors shown in this photo? The green one as well as the white ones, and the female mates for the white ones too.  Having a heck of a time trying to find them, I don't know exactly what they're called! Mouser or digikey would be good...

They're called Molex connectors.  "Molex" is a brand name, but it's kind of like Kleenex these days because most folks refer to these type of connectors as Molex connectors even though there are other mfgs. (Cinch, Kobiconn, Tyco, etc.).  

The power header (the one with the screws) can be found on pages 1519 and 1522 of the current Mouser catalog.  You need to know the pin spacing on the PCB to make sure you get the right one.  To find more, just do a search for "terminal blocks."

The other ones are usually Molex KK Series and you can find the "headers" (the "pin" part usually mounted on the board) and the "crimp terminal housings" on pages 1450-1453.  Again, you need to know the pin spacing on the PCB to get the right ones.  You'll also need the "crimp terminals," which are also on these pages.

There are special crimping and insertion tools, but I've never needed them and I've put a LOT of these things together.  I use a small pair of channel lock pliers (we used to call them "points" pliers back when cars had mechanical points in the distributors) to do the crimp and then I CAREFULLY solder them as well.  Too much solder will ruin the spring part of the "crimp terminals" because it solders the spring part to the stationary part.  I have never had a problem assembling them in this manner.

You can view those pages online at Mouser's website or just download the .pdf of the catalog.

Hope this helps.

Cheers,
--
Don
 

lolo-m

Well-known member
Joined
Dec 14, 2005
Messages
757
Location
Avignon, France
Freddy G said:
Does anyone have part numbers for the connectors shown in this photo? The green one as well as the white ones, and the female mates for the white ones too.  Having a heck of a time trying to find them, I don't know exactly what they're called! Mouser or digikey would be good...

Thanks ;)
They are the same connectors used by Silent Art for the PM and PSU boards. I tried to make the mod as easy to do as possible  ;).
 

SaMpLeGoD

Well-known member
Joined
Jul 19, 2007
Messages
437
Location
Portugal
The -17 supply for the main board was taken? is this right? +17 and -17 goes directly to SCamp Board?
Just to be sure ;)

I'm finally wiring mine!!!

Eddie :)
 

lolo-m

Well-known member
Joined
Dec 14, 2005
Messages
757
Location
Avignon, France
SaMpLeGoD said:
The -17 supply for the main board was taken? is this right? +17 and -17 goes directly to SCamp Board?
Just to be sure ;)

I'm finally wiring mine!!!

Eddie :)
Yes, set the +17/-17V of the PSU660 board to +17V and -17V. The 7812 on the board will give you the needed +12V for relays, lights...
 

SaMpLeGoD

Well-known member
Joined
Jul 19, 2007
Messages
437
Location
Portugal
lolo-m said:
SaMpLeGoD said:
The -17 supply for the main board was taken? is this right? +17 and -17 goes directly to SCamp Board?
Just to be sure ;)

I'm finally wiring mine!!!

Eddie :)
Yes, set the +17/-17V of the PSU660 board to +17V and -17V. The 7812 on the board will give you the needed +12V for relays, lights...

Hello Lolo,

Yeah I understand that, but what I'm asking is: when conecting the SCamp boost to the +17V / -17V, do we need to disconect the -17V from the main board?
I know that the +17V on the SCamp Booster will be regulated to +12V for the relays and stuff... but the wiring for -17V that went to the main board, is no longer needed?

Cheers,

Eddie :)
 

Kingston

Well-known member
Joined
Nov 1, 2005
Messages
3,707
Location
Helsinki, Finland
you still definitely need the -17V wired to the main board! You will wreak serious havoc if you remove the connection.

It is used to bias the many tubes of PM.

Note that +17V is not actually required at all in a plain poorman. You don't really NEED relays and light, and meters. they are just luxury.

[edit]

now that I look at it, isn't there an error on the SCAMP wiring guide? the -17V connection is missing for the main board.

[edit2]

and ground!
 

SaMpLeGoD

Well-known member
Joined
Jul 19, 2007
Messages
437
Location
Portugal
Kingston said:
you still definitely need the -17V wired to the main board! You will wreak serious havoc if you remove the connection.

It is used to bias the many tubes of PM.

Note that +17V is not actually required at all in a plain poorman. You don't really NEED relays and light, and meters. they are just luxury.

[edit]

now that I look at it, isn't there an error on the SCAMP wiring guide? the -17V connection is missing for the main board.

[edit2]

and ground!

Yes, there's missing the -17V and GND conection to the main board on the wiring guide!
Thanks a lot!!

Eddie :)
 

lolo-m

Well-known member
Joined
Dec 14, 2005
Messages
757
Location
Avignon, France
Kingston said:
you still definitely need the -17V wired to the main board! You will wreak serious havoc if you remove the connection.

It is used to bias the many tubes of PM.

Note that +17V is not actually required at all in a plain poorman. You don't really NEED relays and light, and meters. they are just luxury.

[edit]

now that I look at it, isn't there an error on the SCAMP wiring guide? the -17V connection is missing for the main board.

[edit2]

and ground!

Yes, there's two missing wires on the wiring guide  ;D. It was an evidence to me, but I agree it isn't !!!
The PSU feeds the PM660 board with GND and -17V and SCAB Board with -17V/GND/+17V.
 

Moby

BV.8, Bv.11, Bv.12, etc... contact by email
Joined
Jun 3, 2004
Messages
1,843
Location
Serbia
Yes, there's two missing wires on the wiring guide  Grin. It was an evidence to me, but I agree it isn't !!!
The PSU feeds the PM660 board with GND and -17V and SCAB Board with -17V/GND/+17V.
Sorry, my mistake  :-X Here's the revised file  ;D
http://www.mediafire.com/file/mzzwzmmwhy2/PoorMan+SCAB-WiringGuide-R1.pdf
 

Latest posts

Top