Clair Bros Amp

[Northwinds]

Will do Perry, I have no equipment to check anything so maybe a set of Infinity RS1's will be the sacrificial lambs

 

[grapplesaw]

Thanks to Perry I will have my work cut out for me
With the 500's

I am going to see if I can clean out the out system wiring and build a fully comp with possibility of new control board

The 500's have arrived only to find me in their place of origin Hawaii
They can sit till we return in a few weeks for their rebirth to begin.

Aloha
Glen

 

[NavLinear]

The 500's have arrived only to find me in their place of origin Hawaii
They can sit till we return in a few weeks for their rebirth to begin.

Aloha
Glen

That's funny Glen and I'm glad to see you were able to make a deal with Perry.

Have you seen any Hawaiian babes yet? You must post photos!

 

[grapplesaw]

That's funny Glen and I'm glad to see you were able to make a deal with Perry.

Have you seen any Hawaiian babes yet? You must post photos!

Well Dennise there is much beauty in the Islands to be appreciated. I will see what I can do to share with you.

 

[NavLinear]

Cool Glen - what island are you on? BTW I'm jealous.

 

[WOPL Sniffer]

Will do Perry, I have no equipment to check anything so maybe a set of Infinity RS1's will be the sacrificial lambs

Ron, what ya gonna do if the amp is truly inoperative?

 

[orange]

Soly Hit, Ron, not those! Those are good speakers! Please bomb something more powerful than 100W, or have Lee send them here.

 

[Northwinds]

Ron, what ya gonna do if the amp is truly inoperative?

I would just be grateful to own a piece of history. Maybe somebody on here can fix it someday. Looks like Dec 1st end of day for delivery, amp is in Maryland now

I do have a multi tester so maybe someone can let me know what setting to check for DC on the speaker posts before I hook the Infinity's up for Steve's piece of mind. I have 2 sets of the RS1's, they are the best bookshelf speakers I ever heard, like Minimus 7's on steroids

 

[WOPL Sniffer]

Just set meter for DC and check across the set of posts for each speaker. Should be less than .005 vdc. 5 Millivolts (I think that was what I read).

 

[Northwinds]

Just set meter for DC and check across the set of posts for each speaker. Should be less than .005 vdc. 5 Millivolts (I think that was what I read).

That's with the amp plugged in and powered up right? My fingers have been crossed for days that I will get lucky

 

[grapplesaw]

Cool Glen - what island are you on? BTW I'm jealous.

We are on Kauai in Princeville near Hanalei Bay on the north end

This is were all thoughts classic movies were filmed like South Pacific

There are so many long empty beaches to visit here. It's our eighth time here now, just love it
We have three weeks to unwind

 

[Northwinds]

Hope you sampled some of the Kona Gold while there!!! (or Maui Wowie)

 

[grapplesaw]

That 500 is a monster and hopefully someone will resurrect it. Make it better, stronger, more reliable

Hi I just shared this with Perry

If anyone with ideas please pipe in anytime

I want to build a mono channel with one unit
Since one unit is rough I will strip it and put the power supply in a separate case, those things are to Jam packed. I want to put four caps in there and the bridge rectifiers. This will leave the original case nice and empty. It will be full complementary output with option of stereo 550-600 watts or mono 1100-1200 watts. I have a control board that THD+N made similar set up to the Carver C-500 which ran the two channels out of phase so if you connect across the two hot outputs only then you will get double power mono output. Heat will be the big problem. Probably have three cooling fans over the drivers and a big internal to cool the guts.

I have some 1/4" five bar aluminum checker plate to make new face pates with stainless steel handles. The power supply will be fashioned the same with Stainless punch screen in place of VU meters. It should be epic.

I am ordering bits and peices will away so probable January before I start it.

 

[grapplesaw]

Hope you sampled some of the Kona Gold while there!!! (or Maui Wowie)

Thanks Ron

Looks to be lots blowing in the wind here.
Just a note on your wonderfull Claire Brothers amp purchase, which is probable a better choice than my 500 purchase, with a multimeter you can pretty much fix anything wrong with that amp.
Have fun with your piece of History
Glen

 

[WOPL Sniffer]

That's with the amp plugged in and powered up right? My fingers have been crossed for days that I will get lucky

Yup, powered up... Check across the white and black, and then across the red and black. At least then you should be confident that the speakers won't take a hit.

 

[WOPL Sniffer]

All Phase Linear 700 series II amplifiers had PL-36 p.c. boards in them. If my memory serves me correct the Clair Brothers amps were all fully comp amps. Typically using NEC 2SD555's with 2SB600 output transistors. Later 700 series II's like the PRO 700's had the pro version PL-36 pc board with wider traces and the ceramic disc (slow down) capacitors already installed.

The amplifiers in the photos appear to be the transition into the PRO700's. The amp more than likely has press nuts with machine screws instead of sheet metal screws. The chassis may even be a steel chassis and not aluminum. I also see the larger 50 watt Dale resistors in the RC (Zoebel) network. This is because Clair Brothers drove the amp into clipping at 20KHz at 4 ohms. By the way, I have a spare supply of these Dale resistors available.

The Clair Brothers amps were spec'd to do 700 watts (single channel driven) into a 4 ohm load. Dean has a Clair Brother spec sheet that all the amps had to meet before they were shipped out. I will see if I can obtain a copy. NOTE: Clair Brothers later used the Dual 500's on the Pink Floyd "The Wall" tour.

Since these amps are coming from Hawaii, I would expect that they have a fair amount of rust due to their proximity to salt water.

Ed

Lee, the Clair guys replaced some of these transistors on these series 2's with MJ15024 and MJ15025 backplane tranny's. Any issues to look for? I am going to replace a set and get rid of the grease and use SIL Pads and do some playing around. And put a new control board in one also.

 

[laatsch55]

Not a problem with that, the 24,25 combination has been around a long time. If your just getting them up and running nothing wrong with em.

Now if, on the other hand, you were building for ultimate reliability the 95,96 pairs would be the way to go.

 

[Northwinds]

Perry, amp came about a 1/2hr ago. I put the probes to it like you said

Right channel is -0.38
Left channel was like 30.0+ volts when I first put the probes to it!!! I left the probes in and it's going down after a few minutes, right now it is at +01.0 and still seems to be dropping slowly

Could this just be condensation since the amp has not equalized to room temp yet

Is it safe to try out?

Also, when I engaged the power button, it stayed pushed in so I will have to mess with it to get it to shutoff after I let it sit for awhile unplugged and take the faceplate off

EDIT down to +00.9

EDIT +00.8 and holding steady

 

[laatsch55]

Ron, don't leave the probes hooked up and check it with about 5 minutes in between. 30 volts DC is a bad deal even if it goes away eventually.

 

[Northwinds]

Will do Lee, it's was down to +00.7