about the Denon PMA-700 amp

[gaetan8888]

Hello

I remember the very good sound of the first Denon PMA-700 amp from the 80's, in those time I never seen the schematic and can't find the first version schematic of that amp.

But I have the PMA-700AE schematic, what is the differences between the PMA-700 amp from the 80's schematic and the recent PMA-700AE schematic ?

Thank

Bye

Gaetan

[DreadPirate]

This looks like the new one:

http://www.hifiengine.com/manuals/denon/pma-700ae.shtml

Isn't this the old one:

http://www.hifiengine.com/manuals/denon/pma-700v.shtml

[wahab]

This amplifier use Denon s generic schematic that consist
of three serial connected differentials, the first one at the
input using jfets.

Performances of this design are better than both the usual
single differential as in the blameless and the dual serial
differentials as used in Hitachi or its numerous copy ala goldmund.

As an exemple of that Denon s lineup, the POA3200.

[gaetan8888]

Originally Posted by DreadPirate

This looks like the new one:

Denon PMA-700AE | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine

Isn't this the old one:

Denon PMA-700V | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine

Hello

I've look at that pma-700v page, it is a quite recent version.

Thank

Bye

Gaetan

[djk]

The PMA-700V looks like the original with the dynamic bias circuit, the 700AE does not have this.

[portomomo]

Great amplifier, the 700V, very powerful but not invasive,
I loved it. Now the balance pot (220k) died,
and its not easy to find a replacement.

There are 2 service manuals floating around, one with incomplete
schematics.

PM me if you need it.

[Andy5112405]

This was the first amplifier that I had that would show the difference between speaker cables. If you haven't tried them, try using 2.5mm ring main cable (26A for non UK).

[gaetan8888]

Hello

I remember that there was an article in the audio magazine La Revue du Son and wroted by Jean Hiraga in the early 80's , the Denon PMA-700 was tested with a spectrum analyser, the thd spectrum was mostly 2 nd and 3 rd harmonic with no high frequency thd harmonics, doing spectrum analyser tests was quite new in a audio magazine in the early 80's. In those years most transistors amps was not so good.

I was just currious to see the first PMA-700 and see why this amp was so good.

If I understand correctly, the PMA-700V are the same schematic than the first PMA-700 ?

Thank

Bye

Gaetan

[portomomo]

The "V" probably signified "video", as the amp has the capability of 2 video line ins (stereo audio + composite video signal over rca) selectable via switch.

Here some infos on the 700V:
DENON/COLUMBIA PMA-700V

The older 700Z was released 10 about 10 years earlier.
DENON/COLUMBIA PMA-700Z

The (realtively) new 700AE is another build.

What they all have in common, apart the "700" is still a mistery to me.

[gaetan8888]

Hello

I've done a quick look at the PMA-700AE, the PMA-700Z and the PMA-700V schematics.

The PMA-700Z are the one made arround 1979, today it would be a classic circuit but in the late 70 it was quite something.

The PMA-700AE are much more recent and it have a more refine fet input front end in the power amp section and a better power supply.

The PMA-700V are very different, there is no LTP in the front end in the power amp section but it use Ic's, and it also have a better power supply. I don't really like the use of Ic's in the front end of an amp.

Bye

Gaetan