In article , Eiron
scribeth thus
On 11/06/2016 08:43, Brian Gaff wrote:

I had a Sinclair z12 amp that could put out a whole 12 watts, but although
it was not bad for crossover, it did sound kind of fluffy at times.

This one? http://rk.nvg.ntnu.no/sinclair/audio/z12.htm
What a pile of crap!

I became quite adept at fixing Z30s in my youth.
http://rk.nvg.ntnu.no/sinclair/audio/z30.htm
Maybe a much bigger heat sink would have helped
but they hardly ever survived a party.



From that first site......


Like many Sinclair products in the early 1960s, the Slimline relied on
the use of metal-alloy transistors rejected by Plessey for their
original purpose in early transistorized computers. However, they were
good enough for Sinclair's relatively undemanding purposes and were
either incorporated in the kits or sold as separate transistors for a
reported profit of up to 700 per cent. Sinclair's then wife, Ann, was
pressed into service to sort and test them:

"The transistors used to arrive in sacks. About three or four sacks
would arrive, about the size of a sack of potatoes. I had test equipment
consisting of a box that gave a different pitched buzz according to the
transistor, and I must have tested a million of them altogether. It
really became monotonous, because I"d no sooner finished one sack than
another would turn up."

Sinclair was certainly an early convert to industrial recycling, as one
incident shows. Texas Instruments at Bedford used a large batch of
reject transistors as hardcore for a driveway. Sinclair found out about
this, presumably through industry contacts, and rather than shrugging
his shoulders at a missed opportunity negotiated a price for digging the
whole lot up again!

--
Tony Sayer

Sounds about right. I assume you knew about the dodgy ram chips in the
Spectrum which had half the chip duff, and a link in the pcb to select the
working half only in each case.

Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"tony sayer" wrote in message
...
In article , Eiron
scribeth thus
On 11/06/2016 08:43, Brian Gaff wrote:

I had a Sinclair z12 amp that could put out a whole 12 watts, but
although
it was not bad for crossover, it did sound kind of fluffy at times.

This one? http://rk.nvg.ntnu.no/sinclair/audio/z12.htm
What a pile of crap!

I became quite adept at fixing Z30s in my youth.
http://rk.nvg.ntnu.no/sinclair/audio/z30.htm
Maybe a much bigger heat sink would have helped
but they hardly ever survived a party.



From that first site......


Like many Sinclair products in the early 1960s, the Slimline relied on
the use of metal-alloy transistors rejected by Plessey for their
original purpose in early transistorized computers. However, they were
good enough for Sinclair's relatively undemanding purposes and were
either incorporated in the kits or sold as separate transistors for a
reported profit of up to 700 per cent. Sinclair's then wife, Ann, was
pressed into service to sort and test them:

"The transistors used to arrive in sacks. About three or four sacks
would arrive, about the size of a sack of potatoes. I had test equipment
consisting of a box that gave a different pitched buzz according to the
transistor, and I must have tested a million of them altogether. It
really became monotonous, because I"d no sooner finished one sack than
another would turn up."

Sinclair was certainly an early convert to industrial recycling, as one
incident shows. Texas Instruments at Bedford used a large batch of
reject transistors as hardcore for a driveway. Sinclair found out about
this, presumably through industry contacts, and rather than shrugging
his shoulders at a missed opportunity negotiated a price for digging the
whole lot up again!

--
Tony Sayer