Hashimoto sure do make good transformers. I owned a pair of HM7 MC transformers not so long ago.

PYE PF91 mono amplifiers Circa 1956, I really must get round to completing a full service on these.



A little information...

link

Bloody iPad, correct link below

www.radiomuseum.org/r/pye_pf91.html

I had to chuckle when a Swiss manufacturer was making great play out of a feature of their $96000 amplifiers  that PYE we're implementing 60 years ago !

" An interesting design feature is the provision of adjustable positive feedback (in addition to the main negative feedback) in order that the effective output impedance may be reduced to zero to improve loudspeaker damping "

CH Precision M1

A very smar buy if I may say so.

A couple more from my collection of Vintage gear.

Audiomaster 11A from the late 50's, very nice quality Partridge Iron.

W & N also utilised Haddon transformers ( rounded Traffo covers ) however I have an audio preference for the Partridge C core iron.

www.radiomuseum.org/r/w_n_audiomaster_11a_amplifier_25_watts.html

Here you go. Sorry about the crap photo skills

Big toroids are Canterbury windings 340VA 35-0-35 for the output stages, EI transformers are 100VA 25-0-25 for front end.
Rectifier and capacitor pcb's are Avondale audio with 3 caps in parallel and 12uH inductors in between
Amplifier boards are class AB as used in NVA amplifiers. 
Hooked up with 2mm tinned copper wire an silver in ptfe for signal.
Chassis is 60cm x 60cm x 2cm finest chipboard furniture panel from ikea
Mains cable is unknown, no on/off switch or fuses
Back panel sockets were cheap and from Rapid electronics

Soon to change the rectifier and cap arrangement to something much simpler - lose the inductors, schottky rectifiers and hardwired with tinned copper.

The intention is to build it all in to a bespoke sideboard type construction. It will be quite a substantial piece of furniture made entirely of wood (except the heat sinks of course)- I am thinking 50cm deep by 80cm wide by 110cm height with adequate ventilation. The turntable and associated bits are going on top or on a wallshelf. CDP and psu's are next level down (very close to the TT, TT psu and phono stage) and the four or six amplifier mono blocs are going to be spread out to use the rest of the available space.

It is hard to describe to you with out tech drawings or writing an essay but I am trying to build it to classII requirements and it has been in the planning stage for over a year. The only things that will be visible at the front will be volume control knobs, source selector knob and the front panel of the cdp. I having been planning the placement of everything very carefully. The structure will have four wooden levels plus the top, a bit like an enclosed rack but also very different. At least 30cm between levels, all transformers at the front and well away from anything else, dc lines kept as short as possible and soldered, all passive attenuation and selector switch at the back of the structure with the knobs on the end of long 6mm wooden dowel extensions, all signal wiring internal with soldered connections.

I have had to think about it for a long time and as things change along the way to my end goal I have had to revise the plans accordingly. For example I am now set on passive pre so have saved quite a bit of space since I scrapped the active stage and its associated power supply. The mains supply has taken a bit of head scratching. I did not want lots of power cables coming from my dedicated radial circuit so instead decided to use one hardwired power cable for all the power amplifiers with the on/off switch hidden away. Heat management has also had to thought about. The power amps are using very large sheets of 6mm thick aluminium and the cdp will get the same kind of treatment. As I don't want it to turn into a very large pressure cooker I will need ventilation and possibly a fan or two run at a very low dc voltage.

My head hurts just thinking about it all but it will be worth the effort. What will I do if I want to change power amplifiers I hear you say. Well I can truly say that with the ones I am building using nva amplifier boards (kindly supplied by RD) I will want no others and this will be my forever set up and with me for a very long time. CDP I will make easy to change for another but I have a spare transport and another stock un-molested one that could be substituted in. TT and phono stage are going up top anyway so I don't have to worry them.

That is the reason I have been doing so much diy fannying about over the last few years. I am going to get the system to the highest standard I can with in the bounds of my technical knowledge and listening skills before building it in to the housing and (hopefully) forgetting about it. at that point my diy efforts will be limited to second systems and general knowledge accumulation.

Sorry about the essay but you did ask