Aleph60 Dumb Question

[PaulyG]

Hi All:

Don't completely flame me but is the Aleph60 a monoblock? In the service manual it mentions that it is a 60w/channel amp (implying two channels). In addition the manual states that the schematic is for one channel and the power supply for both channels. However, my calculations of idle current would correspond to the approximate 200 watts given in the specification for the overall unit (2.5 amps x 70 volts = 175 watts). So which is it: stereo or mono?

Thanks,

PaulyG

[halojoy]

Originally posted by PaulyG
Hi All:
Don't completely flame me but is the Aleph60 a monoblock? In the service manual it mentions that it is a 60w/channel amp (implying two channels). In addition the manual states that the schematic is for one channel and the power supply for both channels. However, my calculations of idle current would correspond to the approximate 200 watts given in the specification for the overall unit (2.5 amps x 70 volts = 175 watts). So which is it: stereo or mono?

Thanks,
PaulyG

Maybe it is BOTH mono and stereo
Anyway they will soon tell you the answer..

/halo

[UrSv]

You're sure you're not mixing the A30 into the picture? The A60 is a mono block and the power suppply is for one channel. The A30 is a stereo amplifier and the power supply in the schematic in the service manual for the A30 states that it is for both channels. Not so in the A60 service manual.

At least this is my understanding.

[PaulyG]

My guess is that you are correct that the 60 is a monoblock. Here is the text that was confusing me:

Pass Aleph 60 Service Information.

The Pass Aleph 60 has only two gain stages which are biased by current sources. Because of the inherent simplicity of the circuit, it is easy to understand and repair. There are no adjustments.

Figure 1 shows the simplified schematic of the amplifier. Two p channel Mosfets form an input differential pair biased by a current source operating at about 20 ma. The drain of the input Mosfet is attached to the gate of an n channel power Mosfet which forms the active output stage. It is biased by a current source at slightly less than 2.5 amps.

The voltage rails of the supply are at 35 volts, and the amplifier draws approximately 200 watts.

Figure 2 shows the actual schematic for the power supply and one channel.


Maybe I just read too much into that last sentence. Sounds like I need to have enough heat sink for 200 watts/channel, not just 200 watts total.

Thanks for your help,

PaulyG

[moe29]

i may be wrong, but i thought the aleph 60 was the
Volksamp version of the Aleph 5. It's a stereo amp.

The aleph 30 was the Volksamp update of the Aleph 3
the aleph 60 was the Volksamp update of the Aleph 5

but... i might be wrong



moe29
----------------------------
Let's go down the waterfall
Think about the good times and
Never look back
Never look back
-----------------------------

[PaulyG]

Sounds like we need "the one and only" or one of his gang to clear this one up

[Dane]

The Aleph 60 is a monoblock.
Based on the Aleph 2, but at 60W output instead of 100W to use the smaller (more conventional) heat sinks.
There are other improvements to the circuit as mentioned in the manuals, and also in this forum.

[mikewu99]

PaulyG:

I had the exact same questions after reading the service manual for the 60. Look like the 60 service manual is an edited copy of the 30 manual with a few edits missed.

[PaulyG]

Thanks to everyone for their input on this question.

Mike: did you build the Aleph60? It seems to be the right size from a heatsink and transformer standpoint (at least for me )

Paul

[Nelson Pass]

Originally posted by mikewu99
I had the exact same questions after reading the service manual for the 60. Look like the 60 service manual is an edited copy of the 30 manual with a few edits missed.

Well, that's how I write manuals.