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Sunn Coliseum 300 bass Schematic....

Started by ilyaa, March 19, 2017, 05:44:42 AM

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ilyaa

hey!

i know this probably is not a popular topic, as i just spent a bit too long looking for this schematic in vain.

wtf. i found one schematic for this amp and i was trying to work off of it for a bit until i started to notice some strange discrepancies - the IC used for compression in the schematic has 14 pins - the one im working on has 16! - the input IC on the schematic i was looking at was a dual op-amp - the one i'm working on is a 5534!

this is the schematic i was able to find: http://www.prowessamplifiers.com/schematics/sunn/Coliseum_300_Bass.html

anyone have one for the OTHER version, with the 16 pin compression IC and the single op-amp input IC? can't tell what the other differences are...

the power amp in working and im suspecting its the compression section that's the problem (seeing as the IC is fried beyond recognition) but i cant really work on it with this other schematic that doesn't match up at all....

interestingly enough i think this very amp has been asked about in forums through the years.......we'll see if i become just one of many!


g1

What might the number on that 16pin compression chip be?

ilyaa

wish i could tell you!

it blew up - charred.

ilyaa

think ive given up on finding the schematic -

anyone have any luck with asking fender for it?

all i really need, at least to get cracking, is to figure out what this compression IC is - its NOT an ssm2012 or ssm2013 - its some 16 pin thing -

anyone know what the alternate coliseum 300 preamp used for compression IC??

Enzo

How old is this thing?  1960s?  Other era?

J M Fahey

The old schematic you found belongs to the "real" Sun Coliseum 300 from the 70´s ... and it never had compression, nobody did way back then.

IF it does, then it´s something else, a "reissue" or something a new brand owner made to cash on the name.

IF made by Fender, they bought the Sunn carcass but continued only with the PA equipment, *might*  have made some Bass amps, then they should have a suitable schematic, ask them i any case.

We are in complete darkness here, at least post some pictures, including any "Made by / Made in" labels, some gut pictures and some closeups showing any labels on the boards themselves, both silkscreen and copper side.

That said, "compression"  and "16 pins"  in the same phrase, make me think of LM13600, a very popular gain controlled OTA:
http://www.b-kainka.de/Daten/OPV/LM13600.pdf

For starters check whether datasheet pinout matches what you have on PCB or not.

That said, a cracked IC makes me suspect supply overvoltage or some similar gross problem, check you have proper +/-15V rails or whatever that preamp uses.

FWIW that amp might be a generic Korean OEM amplifier with a Sunn label glued to it.

g1

Have you tried over at the sunn forum?  http://sunnforum.ampage.org/index.php
There was mention over there of 2 different schematics depending on the compressor chip.  No one posted the schematic but someone may know the chip used.
http://sunnforum.ampage.org/index.php/topic,10313.msg35604.html?PHPSESSID=24dhorm58ncmslrf2kgtl3cvi7#msg35604

ilyaa

here are some pics!

look familiar?

id say late 70s.....


J M Fahey

That´s why you must post pictures even from burnt stuff.
Model ends in "1N" and I seem to recognize the Signetics "S" .
That plus "16 pins" and "compressor"  makes me think of Signetics NE571N (now NXP)
Check that datasheet pin function matches that in your amp:http://music-electronics-forum.com/attachments/33954d1431700495-ne571-compander.pdf

ilyaa

seems right!!!

pins 8,9 are left open in this design - the VCC/ground pins match - and the input/output pins seems right - 6,11 are open, as well -

it would be really great to have the right schematic - kind of a brain-buster to trace the whole circuit around this thing - but i think you might be right on, J M!


Loudthud

The schematic can be found here: http://www.prowessamplifiers.com/schematics/sunn/Coliseum_300_Bass.html

The compression chip is said to be SSM2012 or SSM2013.

ilyaa

loudthud - i appreciate the link but if you read above in the post the whole reason im in this fiasco is that ISNT right the schematic - that is NOT the chip in this amp -

that schematic is very similar to this amp but, the preamp at least, does not match up. ive got a 16 pin compression chip, as well as some other significant differences....

Loudthud

Trying to attach a different schematic.

[attachment deleted by admin]

joecool85

#13
Quote from: Loudthud on April 04, 2017, 07:39:03 PM
Trying to attach a different schematic.

[attachment deleted by admin]

It seems the forum software didn't like your .gif file.  I think it was mostly due to it being over 7,000 pixels wide.  I have shrunk it down and converted to a .jpg file.  All seems well now!
Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com

g1

Interesting, this matches the 16pin compressor that the OP is looking for, but not single op amp input (5534).   ???