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classe twenty five and classe fifteen

Hi there I am curious to what the differences are between these amp I am guessing that they are built the same years and they have the same design philosophy but the twenty five is the higher model, i cant seem to find to much info on the 25, any info would be greatly apperated.

Thanks,Paul
paulficarella

Showing 6 responses by georgehifi

georgehifi's avatar
georgehifi
10,312 posts
 

I would say no, as the DR25 just had enough current for the 3.6's when I had them.
The low impedance value explains the CS3.6's need for the iron-fisted Mark Levinson No.23.5 to provide control in the bass; the CS3.6 would appear to be current-hungry. 
Cheers George
georgehifi's avatar
georgehifi
10,312 posts
 
Whatever
georgehifi's avatar
georgehifi
10,312 posts
 
If that was true then the 15 would be 150 wpc and it's in fact 175 wpc.
I don't know about the DR15. 


The 25 in the DR25 is short for 250w into 8ohms
https://www.hifiengine.com/manual_library/classe-audio/dr-25.shtml

The idle current power consumption is around 100w with factory adjusted bias give or take. I took them up much higher so heatsinks were at 50c

Cheers George
georgehifi's avatar
georgehifi
10,312 posts
 
willmacc7 posts09-28-2018 6:17pmThanks guys. The model I saw is the later 25 (without DR) ie after founder was stitched up and booted out.

So I take it thats's 25w consumption at standby or idle? And then with any signal/volume its the full class A monte, no matter 'watt'
 :)
The 25 in the DR25 is short for 250w into 8ohms, nothing to do with power consumption.

Cheers George
georgehifi's avatar
georgehifi
10,312 posts
 
willmacc6 posts09-28-2018 1:31pmIf anyone knows the answers, wd be much appreciated.
What’s the wattage consumption on the 25?
And do they produce alot of heat?

Classe DR-25 a very nice reliable amp, sweet and never in your face, a little boring.
They run factory spec 22mV across their .27ohm emiter resistors, around 10watts Class-A per channel at idle, warm to touch.
I raised that and got better sound, so the heatsinks after an hour of idle at 28c ambient were just uncomfortable for the palms of my hands after 6 seconds around 50c, this was more like 35mV across the .27ohm emiter resistors.

Mains fuse ratings are
100v-120v 12amp fast blow
220v -240v 6amp fast blow
This is not indicative of the power consumption but more the inrush current to charge the power supply caps.

If anyone wants the service manual PM me with your email address. I’ll send it out once to the first one, but you must send it to others if they want it here on Audiogon.

Cheers George
georgehifi's avatar
georgehifi
10,312 posts
 

I had the DR25 Nice robust amp).

From memory I recall (long time ago) both DR25 and DR15 had balanced inputs, these were a bit of a hoax as they were just an opamp that summed and they fed into the single ended input afterwards.

Better sound is obtained by just using the single ended inputs straight into the discrete input transistors.

Inputs are also capacitor coupled, I replaced the 5uf electrolytic coupling cap for a better quality plastic one for a further improvement in sound, and increased the Class A bias a bit more so the heatsinks ran at 50c on a hot day 30c.

Cheers George

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