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Audioflyer
26-01-2012, 18:04
Here are a few pictures of the of my rebuilt 1959 Stereoscope 555 integrated valve amplifier.
I've also found out they were made by Clarke and Smith famous for making the Ferrograph equipment.

I've owned it for over 20 years and I paid about £60 for it so I've no idea what it worth now?

I rebuilt it about 10 or 12 years ago as most of the components had suffered due to the heat.

All the resistors were replaced in main areas with 2 watt high-stab carbon film and the ceramic capacitors were replaced with polypropylene ones.

As for it sound quality it very good having comparing it to the small valve TL12's and the Stereo 20 it had a similar sound but it just sounded more neutral.


http://img16.imageshack.us/img16/9760/amp01l.jpg


http://img27.imageshack.us/img27/2126/amp03.jpg


http://img12.imageshack.us/img12/1507/pre03.jpg

Side view of preamp.


http://img269.imageshack.us/img269/9339/front01p.jpg

Front view.


http://img35.imageshack.us/img35/238/pre01h.jpg

Left hand underside of preamp.


http://img842.imageshack.us/img842/7965/pre02.jpg

Right hand underside of preamp.


http://img708.imageshack.us/img708/9374/amp02.jpg

Underside of poweramp.


These old integrated amp are now extremely rare as most of them have overheated in such a small case, this one was in a very bad state when I bought it.
They are well worth restoring if you fancy a challenge!

Does anybody know any more about these amps?
Most of the info I found on the net talks about it being a monitor amp for use in studios?

Sharif.

DSJR
26-01-2012, 22:05
Good grief. That thing terrifies me just looking at it. It would have been a huge labour of love to build it originally, let alone restore it so nicely. A real "Top End" product for its time I reckon :respect:

Alex_UK
26-01-2012, 22:17
Amazing! Keep it and cherish it forever Sharif - one of those items you will always regret selling, I suspect... :)

Audioflyer
27-01-2012, 18:00
I remember it took 12 evenings and a couple of weekends to rebuild it.

At this moment in time I trying to find out where a broken wire goes on one of the input switches and it looking like I going to have to dismantle the preamp section.
It also doesn't help that I lost the schematic diagram!

So if all goes well I'm going to take it to the 'Scalford Hi-Fi Show' in March.

Sharif.

Jonboy
27-01-2012, 19:04
So if all goes well I'm going to take it to the 'Scalford Hi-Fi Show' in March.

Sharif.


Looking forward to it :)

MartinT
27-01-2012, 21:14
Very nice indeed, Sharif. It looks a bit of a bastard to rebuild compared with a Stereo 20. You must be very pleased with it.

shane
27-01-2012, 23:03
One of my great regrets is having owned two of these thirty or so years ago, and not being able to remember what happened to either of them :doh: One of them was the first time I got an inkling into what a valve amp can do. It came in to our shop as a PX, so just for a giggle we unhooked a Sugden P51/C51 combo from our then reference system to see what would happen. The EMI wiped the floor with it (they came badged as HMV, EMI and various other things as well). Bit of a shock, that was. Fortunately I was able to persuade the boss that it wasn't up to much and I might as well take it off his hands!

Wonderful things, but definitely a quart squeezed into a pint pot. They do appear on Ebay very occasionally, generally around the £400 - £600 mark.

And go on, admit it, you really, really love the 'scope on he front....

Rare Bird
30-01-2012, 10:10
I used to have one of those, sounded good but i'm afraid i had to let it go it was in too bad a state cosmetically.

Alex_UK
30-01-2012, 16:00
I used to have one of those, sounded good but i'm afraid i had to let it go it was in too bad a state cosmetically.

Did it have a finger print on it? ;)

Rare Bird
31-01-2012, 12:43
:lol:

stevemalt
15-04-2012, 19:47
Hi

I owned both the 555 and the Pre Amp Version

These where made for the U.S. Market and the contract was cancelled Clark and Smith, sold off the remaining units to Company's like Henry's Radio in Edgware Rd, But could not be sold under the EMI Name. This is the reason that they have so many names, the EMI name on the top left corner was covered with a new name label.

Hope this helps.

Marco
15-04-2012, 20:43
Hi Steve,

Welcome to AoS :)

Before you go any further, please pop into the Welcome area and introduce yourself to our community, telling us what system you've got and what music you like, as you were asked to do in the email you received when you registered.

Cheers! :cool:

Marco.

blu_glo
08-07-2016, 06:03
Apologies for bumping an old thread.
I really wanted to see the pictures?

Also, does anyone have a good copy of the full schematics? Any favours gratefully returned!
- Simon

Audioflyer
11-07-2016, 12:17
I will upload the photos again as imageshack has deleted them! :eek::(:eek:

I also have a circuit diagram of the preamp section the amp is the same as the Mullard 5-10.

Sharif.

blu_glo
12-07-2016, 08:35
I will upload the photos again as imageshack has deleted them! :eek::(:eek:

I also have a circuit diagram of the preamp section the amp is the same as the Mullard 5-10.

Sharif.


Sharif, That would be wonderful, thanks!
They did well to follow the 5-10.
Did they use GZ34 to power the whole lot or semiconductor rectification?
I hardly beleive an EZ81 is up to all that!
I'm particularly interested in the oscilloscope bit which I assume is included in the preamp section....

Simon

Audioflyer
12-07-2016, 08:51
They used a selenium rectifier feed a RCRC network for the B+ dc voltage.

The preamp diagrams do cover the oscilloscope section.

I have a lot going on but I will try tonight to upload the photos and a link to the schematic diagrams.

Sharif.

blu_glo
12-07-2016, 09:23
They used a selenium rectifier feed a RCRC network for the B+ dc voltage.

The preamp diagrams do cover the oscilloscope section.

I have a lot going on but I will try tonight to upload the photos and a link to the schematic diagrams.


Sharif.

- You take your time mate, there's no real hurry!
:pub:

Audioflyer
13-07-2016, 11:21
Here are a few pictures of the of my rebuilt 1959 Stereoscope 555 integrated valve amplifier.
I've also found out they were made by Clarke and Smith famous for making the Ferrograph equipment.

I've owned it for over 20 years and I paid about £60 for it so I've no idea what it worth now?

I rebuilt it about 10 or 12 years ago as most of the components had suffered due to the heat.

All the resistors were replaced in main areas with 2 watt high-stab carbon film and the ceramic capacitors were replaced with polypropylene ones.

As for it sound quality it very good having comparing it to the small valve TL12's and the Stereo 20 it had a similar sound but it just sounded more neutral.


http://i681.photobucket.com/albums/vv175/audioflyer/Forum%20Photos/HMV%20555%20Amplifier/amp01.jpg

Component Side


http://i681.photobucket.com/albums/vv175/audioflyer/Forum%20Photos/HMV%20555%20Amplifier/pre03.jpg

Side view of preamp.


http://i681.photobucket.com/albums/vv175/audioflyer/Forum%20Photos/HMV%20555%20Amplifier/front01.jpg

Front view.


http://i681.photobucket.com/albums/vv175/audioflyer/Forum%20Photos/HMV%20555%20Amplifier/pre01.jpg

Left hand underside of preamp.


http://i681.photobucket.com/albums/vv175/audioflyer/Forum%20Photos/HMV%20555%20Amplifier/pre02.jpg

Right hand underside of preamp.


http://i681.photobucket.com/albums/vv175/audioflyer/Forum%20Photos/HMV%20555%20Amplifier/amp02.jpg

Underside of poweramp.


These old integrated amp are now extremely rare as most of them have overheated in such a small case, this one was in a very bad state when I bought it.
They are well worth restoring if you fancy a challenge!

Does anybody know any more about these amps?
Most of the info I found on the net talks about it being a monitor amp for use in studios?

Sharif.

Photo link restored!

Sharif.

blu_glo
13-07-2016, 12:16
Those are excellent. It looks like your refurb job was made slightly easier by the miniaturisation of modern electrolytic capacitors ;)
Simon.

Firebottle
13-07-2016, 14:23
Very nice photos there Sharif. Very nice to see it and such a good re-build job you have done.

blu_glo
19-07-2016, 12:52
Hi Sharif,

Thank you for reposting the pics they give great detail. Did you find the schematic/link?

Very best regards,
Simon

Audioflyer
20-07-2016, 12:28
Hi Sharif,

Thank you for reposting the pics they give great detail. Did you find the schematic/link?

Very best regards,
Simon


This is all I have for the pre-amp section for the Stereoscope 555.

http://i681.photobucket.com/albums/vv175/audioflyer/HMV%20555%20Amplifier/Stereoscope%20555%20page%2039.jpg

http://i681.photobucket.com/albums/vv175/audioflyer/HMV%20555%20Amplifier/Stereoscope%20555%20page%2039.jpg


I will post a link later to the service manual for the Stereoscope 556 self-power preamp and a hand drawn copy of the power amp.

Sharif.

blu_glo
20-07-2016, 12:59
Thats great, Thanks!

OK so we can see the 'scope tube recieves a 230V 50/60Hz sinewave, presumably from a power supply SECONDARY, on its' vertical axis (produces vertical green line).
Left and right "differences", greatly amplified by the triode just below, are shown as horizontal axis wiggles (from side to side), with "common" signals being inherently suppressed.........

As the 50/60Hz "verticle sweep" is not a linear ramp, like in an oscilloscope, but a sinewave, and thus sweeping both up and down, the visuals are not going to be linear representation of anything; but will give an idea of the lower frequency differences between left and right channels....

Audioflyer
20-07-2016, 20:11
Here is the link for the 556 stereoscope service manual I'm still looking for the power amp circuit diagram.

https://www.mediafire.com/?6m1e0pwddt6qiec

Sharif.

blu_glo
22-07-2016, 07:56
Here is the link for the 556 stereoscope service manual I'm still looking for the power amp circuit diagram.

https://www.mediafire.com/?6m1e0pwddt6qiec

Sharif.

<sounds of digesting information in a frenzy>
I cannot thank you enough, Sharif, I owe you big time - any help needed let me know!
If you say the PA is standard Mullard I have already several copies of such so will not need them.
Including, it appears, the ECL86 one they champion in that manual!

http://www.r-type.org/articles/4-10-1a.jpg (without volume and tone controls....)

I have also found out how the original manufacturer *may* have wound the transformers for the PAs used in these units.....
The link being R.B. Gilson, who must have been to do with the mentioned "Gilson Transformers", see attached scans....