Home built stereo systems

[Biggles]

Did anyone build those music centre projects that used to appear in the seventies and eighties in magazines. I have built plenty of radios and amplifiers over the years but never the whole thing with record deck, cassette player, tuner and amp combined. I seem to remember a project called the "Wimbourne" a long time ago but I may be wrong.
Alan.

['LIVEWIRE?']

I built the PW 'Wimbourne' musicentre, which was published between Sept. & Dec. 1978 IIRC. The radio tuner, especially the FM circuit was for it's day quite advanced, and performed quite well. However the dial calibration didn't match the tuners, either FM or AM. The casssette deck was fairly basic, without an autostop or a 'pause' button, although I added a switching circuit to stop the motor at end of tape, plus a pair of VU meters and manual recording level. I can't post pictures as the Wimbourne is long, long, gone. The record deck I fitted was a BSR C129, IIRC, to which I fitted a Shure M75 magnetic cartridge, having included the optional Mag. Cart. preamp. Whether the performance was much better than if I'd used a decent quality ceramic cartridge I know not

[jamesperrett]

I built a music centre for my sister in the early 80's although it wasn't actually based on a magazine design but more on what we could find in the Edgeware Road on a particular day. I think most of the bits came from RTVC - certainly the amplifier was a 12 watt per channel kit with vertical faders and push button source selection. The cassette deck was a complete unit and I think the tuner was a kit from a PE design (Quasar?). The record deck was a BSR single player with an S shaped arm.

For the speakers we used some cheap Philips 8" drivers with cone tweeters in home built cabinets based on a Martin Colloms design from Hifi For Pleasure magazine. While these worked, they sounded nothing like as good as they were supposed to which isn't surprising when you consider that the drivers we used were probably less than a quarter of the price of the drivers that Martin specified.

[Biggles]

Thanks for the input. It would seem that these sort of projects weren't that popular. I suppose it would entail quite a bit of outlay for the average home constructor. That may have put people off.
Alan.

[dseymo1]

In those days, just as now, it cost more in components to scratch-build a decent audio system than it did to assemble second hand gear of equivalent quality, and redundant Quad, Leak and the like was still available for peanuts if you knew where to look.
Quite attractive if a labour if love as a gift, as in James' case, but not much of a case to be made for personal use.

[Radio tirana]

As a teenager in the late seventies I built up a music centre of sorts using the Sinclair project 80 modules. EMI 13 x 8 speakers in huge infinite baffle chipboard enclosures, a Garrard SP25 MK4 in a homemade plinth fitted with a Goldring G800. All these parts were purchased bit by bit from the small ads in PW or brought back on the bus from one of my many trips to the Edgeware road. I did not bother with a cassette deck as I had a good reel to reel for recording. Not sure if it is just nostalgia or it really did sound better than the very expensive hifi I later bought when I started full time work.
RT

[Biggles]

I remember seeing the Mullard "Unilex?" I think, in ads around that time. When I was tinkering with electronics in the late seventies during my days at school, there was so much free and cheap audio gear around I suppose it wasn't worth the bother to build, even if I could have afforded or sourced the components. I know that some of my mates made their own mobile disco equipment though. They were usually the kids with part time jobs who had a bit of cash flow. I did manage to get a couple of cheap amplifier modules from Bi-Pak to play around with, but it never developed into a full blown music centre. My parent's were probably quietly pleased that I didn't finish it.
Alan.

[Ed_Dinning]

Hi Alan, yes Unilex was well supported by Mullard, I even have some of the booklets that went with it and showed designs for conti-board furniture to house it.
Main project for the 60's was a Bailey 30W stereo amp using Ge power transistors with about 6 input options and separates for inputs. It was well used for about 15 years and is still in the loft somewhere.

Ed

[OscarFoxtrot]

Originally Posted by 'LIVEWIRE?'

I built the PW 'Wimbourne' musicentre, ... I can't post pictures as the Wimbourne is long, long, gone.

Photo attached.

[Oldcodger]

Way back in the early 70's I got the bug of building my own sort of "radiogram ". I'd picked up a AM/FM board cheap, and another to cannibalise for spares. Turned out one of the IF coils was O/C, so cheap easy fix. Record deck came from an old valve unit my wife had owned. Amp & preamp- simple product from a Mullard ideas book. Body- hand made from timber and radio chassis from a local metal place. That gave way to a cassette board ( from maplin) ,and a hand made wooden frame, with a sourced cassette deck. Worked into an old Panasonic ( National Panasonic record deck/amp), and lasted well, even after eldest son ( at age 2 ) ,decided that the cassette deck was hungry and fed it grapes.

[Craig Sawyers]

I've been building my own audio stuff from age 16 through to now - so 44 years. Latest shenanigans is an active crossover, two 4-channel massive power amps, and active dipole speakers.

My first was a Linsley-Hood power amp, then the iconic PW Texan (which still works fine), and onwards and upwards from there.

[Biggles]

I have a copy of that magazine Oscar Foxtrot. I will have to dig it out and read up. I also remember building the Texan amp as part of my apprenticeship in about 1982. I still have it but it has been robbed of bits over the decades. I have a spare board so maybe one day it will live again. Oh dear I feel another project about to start...
Alan.

[MrBungle]

Some more homebrew "stereo system" stuff. This is a mystery item. It appears to be more than just a PA although most of it by volume and mass is PA! A couple of years ago, when I picked up some stuff from a Gumtree lot, I was given this incomplete audio PA with some extra bits in it, which appear to have been derived from music centre type things, a JLH amp which has had the Tim Taylor "more power treatment" and half of a guitar amplifier. I still haven't got around to taking a look at it as time is never on my side. I shall at some point. I've pulled a few bits out to test them, but have found some serious problems. This was accompanied by a folder full of designs as well. It is incredibly over-engineered and made of 3/4mm thick sheet aluminium and steel stock. Think it weighs some 25kg-ish! Photos attached.



And inside.



This is where you can end up with these things and some over-enthusiasm!

Good day though. That, a Marconi 2019A and a Harris HF/VHF PA for £20!

[Biggles]

That's a bit of a monster Mr Bungle. Maybe whoever built it wasn't allowed to put it in the lounge after all that effort, because it just didn't match the decor. Isn't that always the case?

[ITAM805]

In the early 70's I worked for a London TV service department (not on the tools) and was able to 'obtain' most of the components to build my first pair of stereo amps. The circuit was from one of the mags, PE/EE/PW whatever and was about 10W a side using germanium o/p pairs IIRC. I considered myself a competent constructor and was meticulous about the layout on veroboard.

Came the hour when I fired it up, no magic smoke ... and cripes they were loud and sounded great ! But after about 3 minutes it all went quiet on one channel, then the other in quick succession I remember the heatsink, such as it was, was red hot and presumably the outputs has gone short?

Such was my disappointment I never bothered trying to fix them and they was ignominiously junked

[MrBungle]

May have been the quiescent current being too high for the transistors. Usually in amp designs there's a small collector resistor across which you can stuff a meter across and measure this. Some designs didn't bother with this, didn't bother making it adjustable and didn't bother testing with just the one set of transistors in the prototype. PW I'm looking at you...

My first amp kit (maplin if I remember) exploded in a similar fashion as I had no idea what I was doing. Worked for a few seconds, then I smelled a warm smell, then I saw the ghosts of the output transistors rising to semiconductor heaven.

Originally Posted by Biggles

That's a bit of a monster Mr Bungle. Maybe whoever built it wasn't allowed to put it in the lounge after all that effort, because it just didn't match the decor. Isn't that always the case?

Indeed. I get enough stick for the stylish brown Marconi and Philips kit in the corner of the living room.

I am lumbered with a Harmon Kardon Bluetooth thing at the moment because it works with everyone else's iDevices. This thread is dangerously motivating to build something noisy to replace it. I have read the PW Wimborne article and a modernisation that would be interesting to build.

[Ed_Dinning]

HI Gents, it should be easy enough to graft a more modern kit amp on in place of the one spec'd in the PW article. Something like the Texan or similar should be loud enough.

Ed