Pass Aleph 30 and 60

David,

Wrong again. The Aleph 3 has a little more power at 4 ohms. There has been some component changes in the Aleph30 but the design is the same. Have a look at the schematics. There are no differences in topology. This is from the Aleph 30 manual:

Gain 20 dB balanced, 26 dB single ended
Freq. Response - 0.5 dB @ 2 Hz, -1.5 dB @ 100 KHz
Power Output 30 watts/ch @ 8 ohms, 40 watts @ 4 ohms
Maximum Output 25 volts, 5 amps
Distortion (1KHz) 0.2% @ 30 watts, 8 ohms
Input Impedance 47 Kohm single-ended, 52 Kohm differential
Damping factor 100
Crosstalk > -80 dB 20-20 KHz
Balanced Input Rejection -50 dB typical CMRR
Output Noise < 500 uV unweighted
Random noise floor 5 uV typical
DC offset < 100 mv
Power Consumption 200 watts
Temperature 25 degrees C. above ambient
Dimensions 17 " W x 15.5" D x 5.5" H
Shipping Weight 45 lb.
VOLKSAMP
Pass Labs
Po Box 219
Foresthill CA 95631
tel (530) 367 4935
fax (530) 367 4984
www.volksamp.com
www.passlabs.com

This is from the Aleph 3:

SPECIFICATIONS
Gain 20 dB
Freq. Response - 0.5 dB at 2 Hz, 100 KHz
Power Output 30 watts/ch 8 ohms
60 watts/ch 4 ohms
60 watts/ch 2 ohms
Maximum Output 23 volts, 8 amps
Distortion (1KHz) 0.2% @ 30 watts, 8 ohms
1% @ 60 watts, 4 ohms
1% @ 60 watts, 2 ohms
Input Impedance 23 Kohm
Damping factor 100
Crosstalk > -80 dB 20-20 KHz
Output Noise 500 uV unweighted
DC offset < 100 mv
Power Consumption 250 watts
Temperature 25 degrees C. above ambient
Dimensions 12 " W x 12" D x 6" H
Shipping Weight 38 lb.
PASS
Pass Laboratories
PO Box 219
24449 Foresthil Rd.
Foresthill CA 95631
tel (916) 367 3690
fax (916) 367 2193

I have built enough Alephs, so I know this cold.

LIGUY

You are very knowledgeable on this stuff, so perhaps you can answer my question:

Just about every SINGLE-ENDED amp on the planet - including most of the FIRST WATT models - drop power into lower impedances.

This was very true of my 30w FIRST WATT J2, which was down to 12w into 4 Ohms.  This is the reason I eventually sold the gorgeous J2.

So how is it that the little ALEPH 30 can produce 30w into 8 Ohms and 40w into 4 Ohms?

What gives?

Sondeknz

I believe the answer to your question about power into speaker impedance is in circuit topology. Voltage gain stages vs. current gain stages. I don’t have simple details at hand since this information comes from reading lots of articles over the years.
Interviews with Nelson Pass about his circuits are plentiful on the Web and Mr. Pass speaks about things in a fairly straight forward and easy to understand way. I find them both interesting and informative. You may, as well.

Yes, "current source topology" is what the manual said, more power into lower impedence load than First watt Aleph J.

That's one of the differences among the Aleph 3 and 30 versus the First Watt designs. Though none would be ideal with difficult to drive speakers. 

I owned the Aleph 30, got it new on closeout for $1400, First Watt is way more, my how times have changed! 

It was a very good amplifier, It had qualities of tubes along with some of the pluses of solid state. Not the most practical though. High energy use. Ran really hot (which the manual says will cause semi-conductor failures and dry capacitors within 10 to 15 years of use, something to consider if purchasing used).

Also mentioned in the manual- "one hour to reach optimum performance", which I found to be true, you could actually hear the sound changing as you listen.

Nowadays I mostly use a Schitt Aegir (a more efficient quasi class A design that runs somewhat hot but not egg fry hot).

It is'nt quite as good as the Pass was, but has standby switch so it is ready to go out of the gate and has a shorter warm up time. Cost a little more than half of what the Pass did 20 years ago.