Midas 1kw block amps.

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   I expect younger readers will never have seen one of these before....these were the first multi-channel pro. amps. in the very early 1970's.  Was bigger than any 19' amp, more like the size of the amp rack itself, and was at least a 2-man lift.  Power was just 4x 250w into 8 ohms. 

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jbl_man Members Profile Send Private Message Find Members Posts Add to Buddy List Moderator Group Joined: 12 January 2005 Location: London. Status: Offline Points: 11308	Post Options Post Reply Quote jbl_man Report Post Thanks(0) Quote Reply Topic: Midas 1kw block amps. Posted: 28 September 2024 at 5:23pm
	I expect younger readers will never have seen one of these before....these were the first multi-channel pro. amps. in the very early 1970's. Was bigger than any 19' amp, more like the size of the amp rack itself, and was at least a 2-man lift. Power was just 4x 250w into 8 ohms.
	Be seeing you.

Robbo Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 05 December 2005 Location: Shropshire Status: Offline Points: 4297	Post Options Post Reply Quote Robbo Report Post Thanks(0) Quote Reply Posted: 28 September 2024 at 7:50pm
	I remember those well Ian along with the four channel monoblock amps which Charlie Watkins built for some of the major bands with large WEM systems back in the seventies which were extremely similar to the Martin Audio blocks(I wonder where Charlie got the idea from). Slade had a load of them driving their big rig until they changed over to Crown DC300A amps throughout and I can remember selling a lot of the Slade ones which were basically 4x SL100 chassis(very unreliable back then)in one cabinet complete with a nice little foam lined flightcase---in fact that was the best part of them. Edited by Robbo - 28 September 2024 at 7:51pm

njw Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 March 2010 Location: S. Wales Status: Offline Points: 2700	Post Options Post Reply Quote njw Report Post Thanks(0) Quote Reply Posted: 28 September 2024 at 10:05pm
	Looks more like a piece of military equipment than an amp!

M4trix Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 23 June 2009 Location: Croatia Status: Offline Points: 465	Post Options Post Reply Quote M4trix Report Post Thanks(0) Quote Reply Posted: 28 September 2024 at 11:28pm
	I was 4 years old when this was introduced. What's in the output btw ?

London Sound1 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 06 January 2009 Location: East London Status: Offline Points: 283	Post Options Post Reply Quote London Sound1 Report Post Thanks(0) Quote Reply Posted: 29 September 2024 at 6:57am
	I had one of these, it came with factory fitted switches that enabled you to parallel the inputs (not bridging)
	We know what most of the knobs do http://www.soundengineer.co.uk

jammin75 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 08 July 2012 Location: west midlands Status: Online Points: 2476	Post Options Post Reply Quote jammin75 Report Post Thanks(0) Quote Reply Posted: 29 September 2024 at 10:41am
	cud use them as weights to stop my gazebo from taking off !!
	feel the vibes !!! "Who Feels it Knows it" Strong like Lion

godathunder Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 19 July 2004 Location: wicklow Status: Online Points: 1888	Post Options Post Reply Quote godathunder Report Post Thanks(0) Quote Reply Posted: 29 September 2024 at 11:26am
	Ive mentioned it before, but we had one when I was at LMC. We used it as a doorstop
	LOUDER THAN LOUD

madboffin Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 03 July 2009 Location: Milton Keynes Status: Offline Points: 1720	Post Options Post Reply Quote madboffin Report Post Thanks(0) Quote Reply Posted: 29 September 2024 at 4:08pm
	I saw one being used as a doorstop at Concert Sound in the 1990's. Part of Tim Boyle's collection of vintage Midas, I think he had a couple of them (along with Midas console serial Nr. 001). I can also remember them being used at concerts in the early 1970's. They came with a matching flightcase. I am trying to remember what that Martin stack was called. It dates from around 1974. The bass section was known as a B600, with 4x ATC 12" but the combined low + mid box had its own type number, probably SM something. The HF horn is a Vitavox, probably bored out to take a 2" Gauss or JBL driver, and the VHF is an 075/4. Edited by madboffin - 29 September 2024 at 4:14pm

Earplug Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 03 January 2012 Location: Europe Status: Offline Points: 7752	Post Options Post Reply Quote Earplug Report Post Thanks(0) Quote Reply Posted: 30 September 2024 at 1:58pm
	What output devices did these use? There was not that much available back then.
	Earplugs Are For Wimps!

Robbo Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 05 December 2005 Location: Shropshire Status: Offline Points: 4297	Post Options Post Reply Quote Robbo Report Post Thanks(0) Quote Reply Posted: 30 September 2024 at 2:13pm
	Probably 2N 3055 as they were pretty much industry standard in most UK built power amps back then.

Earplug Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 03 January 2012 Location: Europe Status: Offline Points: 7752	Post Options Post Reply Quote Earplug Report Post Thanks(0) Quote Reply Posted: 30 September 2024 at 4:14pm
	Yes, that`s just what I was thinking myself. IIRC, there weren't even complementary MJ2955 PNP devices for them at the time. They only came later.
	Earplugs Are For Wimps!

madboffin Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 03 July 2009 Location: Milton Keynes Status: Offline Points: 1720	Post Options Post Reply Quote madboffin Report Post Thanks(0) Quote Reply Posted: 30 September 2024 at 8:57pm
	Although I have circuit diagrams for a lot of the old Midas console modules, I have never seen one for the amplifiers. They might be 2N3055, but most of the large audio amplifiers of that era followed the designs published in the RCA application notes, and consequently used their range of transistors designed for high power audio.