Power Amplifier Models from the old UK brand "POWER"

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
In general, there are hard to find all brand names, that's wording is also a colloquial word.
This here is such a case.
The name of this company is "POWER" This British company no longer exist.
Perhaps one of you knows who has taken over this company and the service for these devices.
About the follow weblinks you can download photos of some devices of this brand:
Ampli de Sono 2 Canaux Power - Audiofanzine
4 Amplificateurs pro sono [VDS] - Photo, Audio, Vidéo - Achats & Ventes - FORUM HardWare.fr
thank you for your advices in advance
 
no informations? Most models I know are from the "APK" series:
Power APK 160S
Power APK 2100
Power APK 2120
Power APK 2230
Power APK 2240
Power APK 280 B
Power APK 4500
Power BSA 200
Power CPS 300
Power DJ520
Power Double 300
Power Double 400
Power Double Six serie II
Power Jumbo 1000
Power MAGNUM 1000
Power MAGNUM 1200
Power ni501
Power PSA 300
Power PSA 302
Power PSA 303
Power PSA 501
Power PSA 503
Power PSA 703
Power S900
Power Trio 400
Power XK1100

could it be, that this brand is a French brand (most infos that I have found are from there)?
e. g.
http://fr.audiofanzine.com/ampli-studio/power/APK-2070-S/
 

Attachments

  • POWER double 300.pdf
    179 KB · Views: 686
Last edited:
Do you want schematics of Double 300? I have some of them.
Also of some small models (2 X 100W, 2 X 150 W).
I have sold enough "Power" amplifiers from 1985 up to 1989. I have the service manuals.
Power was not (as i know) UK made. They was made in France. Like this in the photo.
 
Correct, Fotios..
They were known to be very rugged amps with not so
bad perfs.
Yes - I have repair some APK2230 devices. Good handcraafted workmenship and not so expensive.
The advantage is, that there are big outside heatsinks without fan and therefore also for home audio good suited (especially for subwoofer power amp).

Also the other products from "power" like mixers and cd players looks interesting.

Do you know which brand has overtaken the brand "power"?
 
Yes - I have repair some APK2230 devices. Good handcraafted workmenship and not so expensive.
The advantage is, that there are big outside heatsinks without fan and therefore also for home audio good suited (especially for subwoofer power amp).

Also the other products from "power" like mixers and cd players looks interesting.

Do you know which brand has overtaken the brand "power"?

I did use a Double Six , the first one , and it was a fairly
solid amp, with a casted aluminium case That was designed
as a giant cooler, a feature that the so called high end PA
amplifier like the Amcron , QSC or Crest never used , as it would
seriously cut in their profit returns...

Sadly, i guess the went out of business in late 80s or early 90s....

The only link i did find is a commercial one that sell the schematics..
Yet another vulture business that loot the manufacturer s
author s rights...

http://protech.audio.free.fr/schemas_ampli.html
 
Last edited:
A brief description of Double 300:
1) Independent power supply per each channel. For this, there are two rocker switches on front. Thus in the case of one channel malfunction, you can switch off it and you can operate the other channel. Two EI type xformers (300 to 350VA each one) are mounted in a thick metal plate in the middle of amplifier. The reservoir capacitors are mounted on the main amplifier boards. The supply rails are in +/-68Vdc. The heatsinks are very rugged and heavy.
2) The amplifier architecture is very common. A simple LTP pair with CCS and without current mirror. There is a trimmer connected at the base of the input transistor which adjusts the DC offset. Small signal transistors used, are 2N5401-2N5551. During this time, there was not rugged PNP TO220 transistors available in Europe. In the VAS stage is used a TIP47 without Miller compensation capacitor. Thus, the VAS presents a large oscillation under square waves injected in input. There is not as well, CCS for the VAS. Instead, is used a large 100μF speed-up (bootstrap) capacitor. The quiescent current circuit, is implemented with a BC547 fitted on the heatsink and a 5K trimmer for adjusting the Iq. The main problem is found in driver transistors. As i said, there was not at early 1980 rugged PNP devices (like the MJE1503X of today). The output is true complementary implemented with 3 pairs of MJ15022-23. For driving the positive output row, is used a TIP47 and the drive signal is taken from its emitter. For driving the negative output row, is used again a TIP47 (NPN) and the drive signal is taken from its collector. Before the TIP47 there is connected a MPSA92 for inverting the signal. To make the thing short, the drive stage of output is in quasi complementary form, instead the output is in true complementary form. Nice trick.
There is as well, a VI limiter circuit, and a very simple but effective (only 4 TO-92 transistors) turn-on delay and DC protection circuit. The output relay has 48Vdc coil. There is as well a classic Zobel and an output inductor.
The service was very easy, due to compact design. There are only 3 PCBs inside, two for the amplifier channels with everything mounted on them, and one with the led indicators of output power and the volume pots of both channels.
From memory, this amplifier was very fast, an obvious thing, due to absence of compensation caps either across the VAS or across the feedback resistor. It sounds very nice, although the great TIM distortion that presents. The only problem was its cooling in PA applications.
I may refer as well, that it was almost absolutely noiseless, due to separate GND nodes of the two channels.
 
I did use a Double Six , the first one , and it was a fairly
solid amp, with a casted aluminium case That was designed
as a giant cooler, a feature that the so called high end PA
amplifier like the Amcron , QSC or Crest never used , as it would
seriously cut in their profit returns...

Sadly, i guess the went out of business in late 80s or early 90s....

The only link i did find is a commercial one that sell the schematics..
Yet another vulture business that loot the manufacturer s
author s rights...

http://protech.audio.free.fr/schemas_ampli.html

From there I get the information about the successor brand, it is "power acoustics":
Sogetronic
and some photo url's
http://www.sonovente.com/Img2/zoom/power-acoustics-st-450-amplificateurs-p19239_1.jpg
http://www.sonorisation-1.com/prix-compare-materiels/images/power-acoustics-ampli-dj-100.jpg
http://www.sonorisation-1.com/prix-compare-materiels/images/power-acoustics-ampli-dj-320.jpg
http://www.sonorisation-1.com/prix-compare-materiels/images/power-acoustics-DJX300.jpg
http://www.sonovente.com/Img2/zoom/power-acoustics-st-900-amplificateurs-p19241_1.jpg
http://www.sonovente.com/Img2/zoom/power-acoustics-st-900-amplificateurs-p19241_1.jpg
 
info


It is important to know that.. POWER was to make by Comel-France
And as well as the Website was to create by the 1st manufacturer original and legal ! for more info : Sono Sav - sav sono
It is also possible to obtain one plans retail, And various service ...:up:
************************************************


 
Here some pictures from an old Power Double 300
 

Attachments

  • POWER DOUBLE3005_1.jpg
    POWER DOUBLE3005_1.jpg
    378.9 KB · Views: 761
  • POWER DOUBLE3006_1.jpg
    POWER DOUBLE3006_1.jpg
    465.1 KB · Views: 769
  • POWER DOUBLE3007_1.jpg
    POWER DOUBLE3007_1.jpg
    438.8 KB · Views: 722
Here some pictures from an old Power Double 300
Thank you for the pics.
Such an amp in defective condition is first choise for users with the aim of evaluation, because there is much space for testing various different caps for the power supply. Also various topologies in the front end are quickly realized for testing. Ideal it would be 5-10 devices of the same amp modell in this assembly kind.
BTW - contrary to my first assumption in the headline, it is a French brand and not a British.
 
Last edited:
about the URLs
ampli power
Sono Sav - sav sono
http://protech.audio.free.fr/schemas_ampli.html
most schemas are listed.

I don't speak french. What means follow exactly:
vous trouverez ici, Tous les schémas
de fabrication POWER ( comel ) antérieur a 1996 indispensable pour leur remise en état, voir fabrication, car certaine doc inclus les typons...
une méthode de réglage est disponible en section "Documentation générale"

an additional question:
about the URL
Sogetronic
there are offers from the brand "POWER ACOUSTICS", the successor of "POWER".
There are several websites with this domain like
http://poweracoustics.com/
or
http://www.poweracoustics.org/
but the associated website I don't find.
Who knows the URL?
 
Last edited:
no advices to post #12?

It is important to know that.. POWER was to make by Comel-France
And as well as the Website was to create by the 1st manufacturer original and legal ! for more info : Sono Sav - sav sono
It is also possible to obtain one plans retail, And various service ...:up:
************************************************
Thank you for this advice.
Unfortunately I haven't success by the try to contact them about
http://sav-sono.servebbs.com/sono-sav/contact-form.php
because I always get an ERROR message by "click on" the "submit" button
Who knows the associated e-mail address?
And who knows the old web address from Comel in France ??
If I know this, I will try about the webarchive to get all informations.
 
Last edited:
Hello, I also own such a Double300. I have the problem that on one side, with the same adjusted volume, only the half power at the output rests. (Also the LES suggest only half.) I would like to fix it, but I can not find a schematic, and some of the resistances are already very affected by the heat. You can not read it anymore. Could I get a schematic? Best regards, exit
 
Hello, I also own such a Double300. I have the problem that on one side, with the same adjusted volume, only the half power at the output rests. (Also the LES suggest only half.) I would like to fix it, but I can not find a schematic, and some of the resistances are already very affected by the heat. You can not read it anymore. Could I get a schematic? Best regards, exit

I have one of those and plan on doing a full restoration real soon, with complete re-cap.

And I'm also still looking for the schematics. There is only one place where I could find them, but those people are just trying to make money off that, so that's not going to work.

I did a reverse engineering on the apk4500 and want to do the same for the double 300. The apk4500 isn't a very complex model, but the double 300 has more stuff and will be much more work.
It would save time if someone could pass on a schematic for it.

My double 300 and apk4500 were in full working order the last time they were used, and that was back in the 1980s. Since that, they've been stored and gathered dust, plus got eaten up very badly by moisture, so both have serious rust throughout the case and other corrosion in many places, such as on the inner pins on the xlr plugs.
Will be a big job to restore them, and will take time. Having schematics would be nice.
I can post the schematic for the apk4500 that I made from reverse engineering it, and it's all in eagle and ltspice. I ran sims on it...
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.