Help identifying amp builder + power ratings

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   Picked up this amp this week and could do with some help identifying if it’s built by a pro builder back in the day or just a DIY job.
Also any ideas on rated power?

Needs a good clean out when I get to the lockup at weekend.

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dnbpc Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 18 March 2010 Location: Manchester Status: Offline Points: 383	Post Options Post Reply Quote dnbpc Report Post Thanks(0) Quote Reply Topic: Help identifying amp builder + power ratings Posted: 07 July 2021 at 9:52am
	Picked up this amp this week and could do with some help identifying if it’s built by a pro builder back in the day or just a DIY job. Also any ideas on rated power? Needs a good clean out when I get to the lockup at weekend.
	Pick & Mix Soundsystem

King Simeon Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 13 January 2007 Location: United Kingdom Status: Offline Points: 788	Post Options Post Reply Quote King Simeon Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 11:51am
	It looks like a JTS from 80's. If it is, prob around 600watts power. I'll see if I can find out for you either way. Edited by King Simeon - 07 July 2021 at 12:27pm
	https://www.facebook.com/KingSimeonSound?ref=stream https://soundcloud.com/king-simeon

valve head777 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 27 July 2012 Location: East Sussex Status: Offline Points: 1781	Post Options Post Reply Quote valve head777 Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 2:34pm
	Definitely a Tubbys, the (speaker) fuse rating might give a clue to power output. Very reliable, should drive 2r, built by someone who absolutely knows the demands of a real reggae soundsystem. I owned one and have used several over the years. Probably 1kw judging by the transistor output count Edited by valve head777 - 07 July 2021 at 2:35pm
	Freedom of choice, choice of freedom.

dnbpc Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 18 March 2010 Location: Manchester Status: Offline Points: 383	Post Options Post Reply Quote dnbpc Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 2:55pm
	Wicked news, I took a punt on it to be fair never expected to get a piece of soundsystem history. Speaker fuse is rated at 10A. Is it a mono block with 6 outputs or are there several channels? Also anyone have an idea where I could get a replacement fuse holder?
	Pick & Mix Soundsystem

valve head777 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 27 July 2012 Location: East Sussex Status: Offline Points: 1781	Post Options Post Reply Quote valve head777 Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 3:37pm
	It's a mono block amp. Nice piece to get hold of..
	Freedom of choice, choice of freedom.

simonp1100 Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 01 September 2008 Location: Bristol Status: Offline Points: 1110	Post Options Post Reply Quote simonp1100 Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 7:53pm
	Looking at the heatsink, i assume there are two heatsinks with 4 MOSFET's per heatsink ?, looks like the standard 2SJ50 - 2SK135, so if there are 8 MOSFET's in total, this would give a max output of 400 Watts.

valve head777 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 27 July 2012 Location: East Sussex Status: Offline Points: 1781	Post Options Post Reply Quote valve head777 Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 8:05pm
	Mine, which was rated at 1k, had 4 heatsinks. But this looks older and could well be a lower power one.
	Freedom of choice, choice of freedom.

dnbpc Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 18 March 2010 Location: Manchester Status: Offline Points: 383	Post Options Post Reply Quote dnbpc Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 8:51pm
	That’s a shame that it’s not got a bit more juice but should do a nice job of powering the quad 8” box I've built for the basement for house parties.
	Pick & Mix Soundsystem

Xoc1 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 15 October 2012 Location: Devon UK Status: Offline Points: 397	Post Options Post Reply Quote Xoc1 Report Post Thanks(0) Quote Reply Posted: 07 July 2021 at 9:16pm
	It should do about 550W into a 4 ohm load- dependent on the PSU transformer being man enough - but it will do that as a solid continuous output. If it is all working properly should sound very nice indeed.

Earplug Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 03 January 2012 Location: Europe Status: Offline Points: 7216	Post Options Post Reply Quote Earplug Report Post Thanks(0) Quote Reply Posted: 08 July 2021 at 6:36am
	Pop in one of these:- https://www.ebay.com/itm/361473254497?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 And you'll have your 1k!
	Earplugs Are For Wimps!

monkeypuzzle Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 25 January 2005 Status: Offline Points: 924	Post Options Post Reply Quote monkeypuzzle Report Post Thanks(0) Quote Reply Posted: 08 July 2021 at 7:30am
	If you can get a meter on it, measure the rail voltage coming out of the transformer.
	blah blah blah blah blah......

simonp1100 Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 01 September 2008 Location: Bristol Status: Offline Points: 1110	Post Options Post Reply Quote simonp1100 Report Post Thanks(0) Quote Reply Posted: 08 July 2021 at 8:09am
	The 2SJ50 & 2SK135 are + or - 160V MOSFET's at 100 Watts dissipation so you may get a little more & it also depends on the secondary DC voltage rails as well, again as someone else has already said can you measure the DC supply rails ?.