Bridging a PL 700B

[laatsch55]

Hi Northwinds;
I have a large listening room. I built my house around my sound system. The room is approx. 24 by 35 feet, 17 ft ceiling. I was using 2 Cerwin-Vega M horns in the corners,(sensurround style). Very efficient above 40 Hz, mostly noise below that. I did not want to spend $5k on two JBL 4546c subs, (Pink Floyd needs stereo sub woofers). I enjoy brief sessions at 115 db and found that my PL 700 was working fairly hard to drive my new RCF LF18X401 drivers. With a P to P max cone ex. of 50 mm, it looks like MORE POWER is called for.
My goal is to build a HIFI system that can produce PA system levels.
I will attach photos of my self designed Line Arrays. I have what I think is a unique design feature and will post photos when I a chance.
I have rebuilt one of my 700B's with the nice White Oaks main pcb and ON MJ21196's outputs but this still only produced about 400 (maybe 420) WPC before clipping.

Pete, I have a Carver PT 2400 that will do 3,000 bridged into 4 ohms. I can send it to you and if ya like it, you can send me 600.00 and we'll call it good...

Stereo----750 into 8, 1200 into 4, 1500 into 2...
Bridged mono...2400 into 8, 3000 into 4...

 

[Peter Stoffregen]

I have played with a lot of BGW 750's, They were used for the sensurround systems in theatres in the 70's. I wish I kept one. They were very reliable, with a nice modular design, but I don't think they had quite the same punch as my Phase Linear 700's. The PL 700's have those crazy + & - 100 V power supply rails (with 100 volt filter caps). Everything just on the edge, but I really do not want to part with them. I hear a lot of audiophiles describing the sound of their amplifiers, I don't get it. In my modest opinion, an amp should be transparent and add nothing. The PL's are quiet, clean and powerful. ( OK maybe a loud pop or two, in the last 25 years). Besides that, they have been perfect, until now with the addition of my slightly less efficient RCF subs.
I am looking for another amplifier with a (simple) brute force power supply and HIFI type class AB design,
but with even more power.

 

[laatsch55]

Chck the post above yours..

 

[Northwinds]

Pete, I have a Carver PT 2400 that will do 3,000 bridged into 4 ohms. I can send it to you and if ya like it, you can send me 600.00 and we'll call it good...

Stereo----750 into 8, 1200 into 4, 1500 into 2...
Bridged mono...2400 into 8, 3000 into 4...

HOLY SHIT...

 

[Peter Stoffregen]

Thanks laatsch55; I will keep your amp in mind, I will look for a schematic and more specs. The RCF drivers have a 1500 Watt "AES" power rating. So I am looking for an amp that can get the most out of them. In hind sight, should have spent the bucks on the JBL drivers.

 

[laatsch55]

Hookay...

 

[laatsch55]

What is AES??

 

[Peter Stoffregen]

Audio Engineering Society

 

[laatsch55]

Gotcha...

 

[Peter Stoffregen]

http://eaw.com/docs/6_Technical_Information/StudyHall_and_TechNotes/Power_Handling.pdf

RCF claims to adhere to the test methods described in the above pdf

 

[P.L.F.]

Depending on who you talk to the CS800 is a BGW750 with frills. It has no resemblance to PL 700B. The 750 was used as a sub amp in pro apps. It will drive anything you put on it, reliably. see the link. http://en.wikipedia.org/wiki/BGW_Systems

Although quite old, I really like the BGW 20 crossover for use with a sub. I used them in clubs in the 80's. Speaking of crossovers, the JBLBX63 is intended for home systems.

...And more info on CS800 vs. PL700 is here: http://forums.phxaudiotape.com/showthread.php/3293-Phase-Linear-and-Pink-Floyd/page9 - post 86 with links..

 

[P.L.F.]

View attachment 16427 This is my line array design. The cabinet is 84" tall so it will fit in a listening room with 8 foot ceilings. The cone drivers are over lapped to keep centre to centre distances of the drivers to less than 5" to allow true "line radiation" (minimal interference pattern) up to 2 kHz. Above that, the plannar tweeter line takes over.
Still doing some tweaking, and I would welcome any comments and be happy supply more details.
I have done considerable research on line array principles before starting this project.

Wow, veeeeeery impressive...

A colleague of mine has slightly smaller system targeting the highest efficiency possible (amps are valve SE / PushPull and VTL MB300 in option - see the pic).

But your arrays are overwhelming ...

 

[laatsch55]

Pete, have you heard of Epiphany's?

 

[laatsch55]

On the subject of bridging......have you read Rod Elliott's treatise on the subject? One of these days I'm gonna bridge a PL 400 or 700 just to see it done..

 

[Northwinds]

...And more info on CS800 vs. PL700 is here: http://forums.phxaudiotape.com/showthread.php/3293-Phase-Linear-and-Pink-Floyd/page9 - post 86 with links..

I am not seeing a lot of info, just tidbits. I would really like to learn more about the CS800 since I have a super clean one sitting in the garage and I want to use it but I want to know what can be done to make it even better

 

[Northwinds]

On the subject of bridging......have you read Rod Elliott's treatise on the subject? One of these days I'm gonna bridge a PL 400 or 700 just to see it done..

I thought you said that was a no no so I will be watching to see how you make out

 

[laatsch55]

It is a no-no. That's why it must be tried...

 

[P.L.F.]

I am not seeing a lot of info, just tidbits. I would really like to learn more about the CS800 since I have a super clean one sitting in the garage and I want to use it but I want to know what can be done to make it even better

I was referring to resemblances to PL700, as it was the thread context.

But there is plenty info regarding CS800 checking / restoration on DiY Audio, e.g. http://www.diyaudio.com/forums/solid-state/216627-peavey-cs-800-issues.html or cleaning: http://www.youtube.com/watch?v=040rht6lIQU ... Actually on youtube one can find more, like: http://www.youtube.com/watch?v=VzptWAgOTHo that one is really funny... Some more research needed ..

 

[Northwinds]

Ok I see what you mean. My CS800 is far different looking. It pretty much looks like what all Joe's control and backplane boards, no TO3 circuitry. I took the top of this morning and cleaned out a bit of dust in areas, not much at all. I like the flow through design over the transistors with the fan which is wicked quiet. I took a few pics and will post them up in a bit. Looks like the boards were matched perfectly and the tranny has a notation of 101 so I am assuming that's 101 volt? The caps have a large board bolted to them, odd looking bluecaps, very short and fat. I like how the amp is set up, almost like modules

 

[Northwinds]

Both boards have the same notations