Sinclair Z30/Z60

[Nymrod121]

Just found these in a bag of assorted Os&Ss...
I wonder how Sir Clive is these days - I always chuckle at the recollection of that wonderful moment in 'The Micro Men' (Alexander Armstrong et al) when the techies are sat around having a meal, one of whom is using a pair of meter prods as chopsticks
Guy

[crackle]

It looks like you did the same as me, for ever changing the driver and OP transistors for larger ones.
The only time my setup lasted for more than a few days was when I changed the OP transistors for 2N3055 types mounted on a large finned heat sink..(I think that was what I used)

But I thought his stuff was brilliant at the time, I just kept buying it from my first Micro 6, through to Z12 amps right up to my project 60 "HiFi".

More here http://rk.nvg.ntnu.no/sinclair/audio/amps.htm

Mike

[M0FYA Andy]

I had a pair of these as a student. After 'retransistorizing' them twice after they suffered catastrophic failure, I rebuilt them with transistors mounted on big external heatsinks and had no further trouble. I also rebuilt the preamp, which used flimsy skeleton presets as the volume/balance and tone controls with external proper potentiometers.

Andy

['LIVEWIRE?']

I still have a Project 60 somewhere, bought second hand years ago. Like you, Andy, I changed the skeleton pre-sets, in my case for better ( enclosed ) Piher or similar types. I also had to repair the PSU, in addition to which I found that there was hum pickup due to the routing of the wiring to the on/off switch, so I fitted a separate toggle switch mounted several inches away from the original switch bank. At some point the original amplifier modules failed for the second time, so I replaced them with a pair of similar amp. boards from, IIRC, Bi-Pre-Pak.

[D_S_J_R]

Didn't Naim take this RCA based circuit, remove the output inductor and add huge supplies?

[Nymrod121]

If anybody wants these (FoC), just let me know; if nothing else, the Sinclair logo on the heatsink plate of one of them is in good nick => 'scannable' ...

Guy

(Mods, please feel free to split this into the FS/W section if needs be)

[crackle]

Hi Guy
I wouldn't mind giving them a home, for nostalgia's sake.

Thanks
Mike

[Andrew2]

In my younger days, my friends and I ran a mobile disco with an amplifier made from two Z50's and a PZ8. Never a spot of trouble, although the PZ8 did trip out once or twice.
Like Mike, I was a big fan of Clive's stuff and had lots of it from the Micromatic to the Project 60 FM tuner and a Cambridge calculator, which I still have. I also had a pair of Q16 speakers which were really not very good.

[Nymrod121]

Mike: these are off to you asap

Andy: I had one of the Cambridge Scientific calculators (in white) when I first started college wa-a-a-ay back - also a Micromatic which was incredibly good at picking up Luxembourg 208

Guy

[Andrew2]

Ha! I loved my little Micromatic. It was the early 3 transistor one that seemed a bit more lively than the later two transistor version, and if I adjusted the reaction coil to within an inch of its life the set would pick up Radio Caroline North, not an easy task here in East Manchester even on a typical Japanese superhet.

[crackle]

Thanks very much Guy

cheers
Mike

[M0FYA Andy]

I'm rather surprised that folk are so enthusiastic about Sinclair products. My memories from the late 60s early 70s period is that we put up with them because it was all we could afford as schoolkids/university students. Although there were some clever bits of design, they were let down by being 'stripped to the bone' circuit-wise and with some dreadful bits of mechanical design.
I was at uni in Bangor from '70 to '73 doing my degree in Electronic Engineering, and we had an evening lecture by a couple of young engineers from Sinclair, ostensibly to talk about circuit design, not to discuss Sinclair products. However we were very unfair on them, and ripped them to shreds with questions along the lines of 'why does my xxx keep blowing up?' or 'why does my yyy keep falling apart?' or 'didn't Sinclair test using two of the PWM amplifier designs together as a stereo system. The poor lads, not much older than us students, were almost reduced to tears.

Andy

[Nymrod121]

Nostalgia can be very forgiving, promoting (as it often tends to) a degree of selective amnesia

[Andrew2]

I think Andy M0FYA makes a good point. OK, the products were generally somewhat under-developed and tended to be fragile both electrically and physically, but they were interesting (for me especially the little radio designs) and CHEAP.
Their low price meant that if they did blow up it wasn't the end of the world and those of us who liked fiddling with stuff (probably a large proportion of the market) could have a bash at repairing and improving it. I think the company knew this.
Our disco amp used a Project 60 preamp and we thought nothing of replacing those cruddy presets with proper pots on lengths of screened leads leading to our own front panel.
Unlike Andy, I'm always surprised by the amount of flak Sinclair stuff gets on the 'net, and often wonder if there's a bit of exaggerration going on for the sake of it. None of our group ever had much trouble with Sinclair stuff. I think I blew up one Z30, but only by shorting the speaker while running at near maximum ergs. I'm sure some of the stuff worked poorly - or not at all - because of the poor constructional skills of some buyers. Clive's obsession with miniaturisation didn't help here.
Well, that's THAT off me chest!

[TALKINGWITHPYE]

Hi from Dave, I had amplifiers similar to the z 50 though not Sinclair. I used them with a homebrew mixer for a portable pa system mainly used for events in my church before they got their own pa equipment. They gave me good service.