New Toys for OldBoy- Soundcraftsmen amp

Last night I gave my little PCR-800 a run with a Chesky demo disc that Fishface
brought over. We ran the Infinity RS 2.5s and were both impressed by the dynamics and overall sound this shoe box was able deliver. A big advantage of
amps of this ilk, is there ability to handle what ever load they are connected to.
In this case, the Infinities are known to drop below 2 ohms. This would be end of many contenders. I still would like try a vertical biamp with 2 PCR,s because 1 is just not enough with the 2.5,s.
 
jbush:
That is an amazing light show on the RA7503! Both the Soundcraftsmen preamps I own- DX-4100 and Sp-4002 have red lights that "blink" to the music input. Plus I have a DBX "boombox" subharmonic synthesizer that also "blinks" to the input. So between the boombox, preamp and amp, it's a hell of a red/green light show!
Not as cool as yours, but "trippy", as we used to say...
wizargoz
 
jbush said:
I have to disagree with SleeperSupra. I believe the RA5501 is just a LA2502 without the LEDs. I say this because I believe my amp that is the same as my LA2502 is the RA5501 (I will check when I get home). If this is the case, the specs listed by goat67 would apply to the RA5501. I probably wouldn't pay over $200 for it, and then only in near perfect condition.

Here is an RA5502. If you look closely, you will notice the only difference between this and the LA2502 is the of speaker selector buttons on the frontof the LA.
http://www.soundcraftsmen.com/ra5502.htm
Click to expand...


My mistake...
 
thedelihaus said:
I'm sure this thread will drive the price up.


Another issue that initially kept me away was there was a tendency for failure if you didn't properly turn on/off the amp-pre-amp. Seems techs didn't always know the proper way to fix it, but there is a workaround.

So just be careful when turning on your pre and amp.
Click to expand...

As I understand from reading the service manual this issue was covered in a production Mod it applied only to the early MA5002 PA5001 and EA5003 models.


As far a turning on and off. I do the following

On
turn on pre amp
turn on amp wait for relay to activate
engage speaker selector
turn up volumn preamp

Off
turn down volumn preamp
disengage speakers
turn off amp
turn off preamp

Its worked for me for the past twenty eight years
 
Here is what I have learned from various sources on the Soundcraftsmen models

First introduced models Home Versions
Power Output 250 Watts 8 Ohms 360 Watts 4 Ohms
MA5002 VU Meters and AB Speaker Selector
EA5003 Equalizer Amp (EA) add an Equalizer No Meters
PA5001 No Meters No Speaker Selector

Internal info Circuit boards connected using point to point wire wrap connections

Circuit boards

Power Supply / Protection

PreDriver
No DC Offset adjust must correct by matching transistors

Output Driver Board Transistors used per chan

6 2SD665 marked 8 for later models
or
6 Toshiba 2SD424 for earlier models marked 4

1 Fairchild 2N6285 PNP Darlington marked 25
1 Fairchild 2N6282 NPN Darlington marked 26
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Next Generation MA5002A PA5001A
Power Output 250 Watts 8 Ohms 375 Watts 4 Ohms
MA5002A LEDS and AB Speaker Selector
PA5001A No LEDS No Speaker Selector

Introduced the Professional Series RA7501 RA7502 RA7503 RA6501 RA5501 RA5502
Bridged Mono Mode supported
Balanced unbalanced Inputs

RA7501 Gain Controls and Clip Indicator
RA7502 Gain Controls Varaportion Ind Clip Indicator and Power LEDS
RA7503 Gain Controls Varaportion Ind Clip Indicator and Power LEDS Eq LEDS
RA6501 Same as RA7501 but without balanced Line No Bridged Mode No Gain Controls

Power Output Bridged Mono 750 Watts 8 Ohms
Stereo 250 Watts 8 Ohms 375 Watts 4 Ohms

The Internal construction changed to use molex connectors for interconnects between circuit boards same boards used between series

Circuit boards

Power Supply / Protection
Same board used on PA5001A MA5002A RA7501 RA7502 RA7503 RA6501

PreDriver
No DC Offset adjust must correct by matching transistors
Same board used on PA5001A MA5002A RA7501 RA7502 RA7503 RA6501

Output Driver Board Transistors used per chan
*4 Toshiba 2SD665 marked 8
*4 Toshiba 2SB645 marked 5
1 Fairchild 2N6285 PNP Darlington marked 25
1 Fairchild 2N6282 NPN Darlington marked 26

* Note PA5001A and MA5502A have only 3
Same board used on PA5001A MA5002A RA7501 RA7502 RA7503 RA6501

Input Board used on RA series only

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Info on LA2502, LA2501, RA5501, RA5502, DJ600, Reference 2, PA2X200
2 MOSFET 2SJ50 Output Transistors
2 MOSFET 2SK135 Output Transistors

LA2502 LED Power Display 2 speaker selection Gain Controls
LA2501 No LEDs and no gain controls

RA5502 LED Power Display Gain Controls
RA5501 No LEDs and no gain controls

125 Watts 8 Ohms
190 Watts 4 Ohms
THD less than 0.02%
Weight 30 lbs
 
Last edited:
Goat67 Its about time some "actual" info was confirmed and made available on these units, considering the little that has been shared. Which units where using
MOSFET outputs? Or did they all run them?
 
MOSFETS
Where used on some other later models I am not familiar with these but I am bidding on a couple right now on the auction site.
If I find out more I will post it
 
Bravo goat67!!! What a wealth of information.

If anyone needs the owners manuals, I have them for the TG3044 and the RA7500 series. The only schematic I have is for the PCR-800.

Does anyone know who runs:
http://www.soundcraftsmen.com/index.htm
It would be nice to get as much Soundcraftsmen info in one place as possible. I noticed this site hasn't been updated for a couple years. I would be willing to scan my manuals and send those and whatever pictures anybody wants. I hope MTX wouldn't have a problem with that.
 
jbush said:
Bravo goat67!!! What a wealth of information.

If anyone needs the owners manuals, I have them for the TG3044 and the RA7500 series. The only schematic I have is for the PCR-800.

Does anyone know who runs:
http://www.soundcraftsmen.com/index.htm
It would be nice to get as much Soundcraftsmen info in one place as possible. I noticed this site hasn't been updated for a couple years. I would be willing to scan my manuals and send those and whatever pictures anybody wants. I hope MTX wouldn't have a problem with that.
Click to expand...

That site is not very accurate an not to deep in info.

MTX has long lost interest in this old equipment. Doubt they would care.

I have a bunch of info on this vintage of Soundcraftsmen I would like to get a sticky or something set up so I could load it to AK and then it would be available for others for reference. I would need to scan alot of it. But it would be worth the effort.

Because this thread will be long forgotten in a month
 
goat67 The Hfi Engine is where a lot of AKers have down loaded manuals etc.
A great site.
 
Anyone have a scanned service manual for the MA5200?

My neighbor just passed one on to me that has very bad distortion on the right channel and I'd rather fix it than part it out….. Any help would be appreciated!
 
Ya I found the same thing. What I was looking for was a sticky or something so I could get all the info to the site and not have to keep it in my upload storage because eventually I will need to delete something and then the info would be gone.
 
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