Dunlap -Clarke Dreadnaught 500 Power/ amp.

[Raymond]

Hello to all,
I'm a new member and this is my first thread...
Does anyone have any information on the Dunlap-Clarke Dreadnaught 500 power/amp? The only info I have on this model is that it was made in the U.S.A. circa 78, it was imported to England by Exposure Electronics before they made their own amplification. I believe it delivers about 600watts R.M.S. per channel into a 2ohm load and that's all the info I have on the unit.
Can anyone enlighten me?
Regards
Raymond.😎

 

[Nelson Pass]

Well, it's been about 28 years, but I had occasion to peer inside one, and it seemed to be a conventional push-pull AB follower with a really big output stage. It recall that it had MJ802 and MH4502's (I could be mistaken) which were the biggest BJT's you could get back then and some serious fans.

I subsequently had a nice conversation with the designer (Ron Dunlap?) at a show. A very smart, nice guy, who by then had quit the business for other pursuits.

Probably not even Jam has schematics for this, but it was a simple enough circuit that you could reverse engineer it or otherwise service it if you had to.

 

[jam]

You are right Mr.Pass, I dont.😱

Jam

 

[djk]

Single ended diff inputs with an active current source for the VAS (like a Pass A40). 2N6030/5630 outputs parallel connected in the D250, series/parallel connected for the larger amps (like a Dynaco ST416). I think I still have the schema for the preamp and D250 power amp.

 

[Dj BASS AMP]

i need to a circuit of 600W RMS AMP to 2 - 1 Ohm speakers...

 

[Raymond]

Thank you Nelson,DJK and Jam for your positive response.
I bought the amplifier here in England together with the matching pre-amp, the power amp sounds a lot better than some of the well respected designs..... I use it with a Naim 42.5 pre/amp at the moment and it sounds very detailed and informative. I think that the power caps will need replacing as they are the original ones. I don't use the matching pre/amp as it sounds very constricted. My speakers are Linn Isobariks so I opted for an amplifier that will deliver a fairly large output into a low impedance load "I think the Linn's drop to 2ohm.
Thanks again.
Regards to you all.
Raymond.🙂

 

[Nelson Pass]

Single ended diff inputs with an active current source for the VAS (like a Pass A40). 2N6030/5630 outputs parallel connected in the D250, series/parallel connected for the larger amps (like a Dynaco ST416). I think I still have the schema for the preamp and D250 power amp.

Great! Please post it if you can find it.

 

[planet10]

Dunlap-Clarke Dreadnaught 500 power/amp?

We had one of those thru the shop when i worked hifi. Not sure which one. Nice amp, but became unobtainable.

dave

 

[Raymond]

Re: Re: Dunlap -Clarke Dreadnaught 500 Power/ amp.

We had one of those thru the shop when i worked hifi. Not sure which one. Nice amp, but became unobtainable.

dave

Thanks for the info Dave. It does sound nice, although it's quite old and there are better power amps out there it's the best power amp I have heard for quite a while and it cost me peanuts.


🙂

 

[planet10]

Re: Re: Re: Dunlap -Clarke Dreadnaught 500 Power/ amp.

it's the best power amp I have heard for quite a while and it cost me peanuts.

The Frugal-phile(tm) in me loves those peanuts. Did you ever have a NAIM power amp in your system?

At the time we had the DC we were also selling NAIM 160s & 250s. The NAIMs were a bit more refined, but didn't have the balls of the DC.

dave

 

[Raymond]

Re: Re: Re: Re: Dunlap -Clarke Dreadnaught 500 Power/ amp.

The Frugal-phile(tm) in me loves those peanuts. Did you ever have a NAIM power amp in your system?

At the time we had the DC we were also selling NAIM 160s & 250s. The NAIMs were a bit more refined, but didn't have the balls of the DC.

dave

Hello Dave, no I haven't tried a Naim 160 or 250 in my system...I couldn't afford one. Your comments on the DC are very reassuring.
Glad I bought it now. Cheers.
🙂

 

[Raymond]

Single ended diff inputs with an active current source for the VAS (like a Pass A40). 2N6030/5630 outputs parallel connected in the D250, series/parallel connected for the larger amps (like a Dynaco ST416). I think I still have the schema for the preamp and D250 power amp.

Hello DjK, did you manage to find the schematics for D250 and
preamp? I would be very grateful for any more info you might have on the said amps. Thanks.

Regards,
Raymond

 

[EchoWars]

Single ended diff inputs with an active current source for the VAS (like a Pass A40). 2N6030/5630 outputs parallel connected in the D250, series/parallel connected for the larger amps (like a Dynaco ST416). I think I still have the schema for the preamp and D250 power amp.

I'm gonna bump this up, since I have a buddy who recently acquired a dead D250 amp.

Any hope of a schematic there djk??

 

[JJT]

Dunlap Clarke 1000 schematic

While going thru a box of old stuff, I found a schematic
for the D/C 1000, Also, the Bose 500, the Infinity
Hybrid, and the Delta Concept one guitar amp.

They are blue-print size papers, not easy to scan.

I'll work on it.


JJT


www.jtashjian.com

 

[finwbu]

Hi JJT, can you send me a copy from your Dunlap -Clarke Dreadnaught 1000 Poweramp?

thanks walter

 

[avnut57]

Dunlop Clarke "Dreadnaut" still cranking!

We had one of those thru the shop when i worked hifi. Not sure which one. Nice amp, but became unobtainable.

dave

I am new to this forum usually stay on AVS but I have a DC "dreaudnaut"
I think it's the 250, I had new caps put in it & it plays really nice, sounds like a Cyrus to me very musical. I'm ready to let it go & I saw the conversation & thought I'd say hello

 

[avnut57]

Working DC 250

I'm gonna bump this up, since I have a buddy who recently acquired a dead D250 amp.

Any hope of a schematic there djk??

I have a working dc 250 can I be of any help?

 

[Nelson Pass]

It was a reasonably simple amplifier, you might be able to trace the front
end schematic which is probably the only mystery.

BTW I spent some time talking to Ron Dunlap at CES many years ago.
A genuinely nice guy.

😎

 

[djk]

I sold my amp and pre to another forum member, and he has the service data too.

As NP says, the DC 250 amp is pretty easy to reverse engineer, reminds me of his A40 design (with discrete drivers).

 

[IceMan57]

Dunlap Clarke Schemetics

I have a Dunlap Clarke 10 Fet preamplifier. I am in search of schematics and manual for this device. Finding information on Dunlap Clarke devices is well, difficult.