The clocks have gone back ...

[Vipersan]

...but a long way back in my shop..
Back to the early nineteen seventies in fact ..
Nelson brought me a Ferrograph Amp for repair ...
In truth I have worked on this amp before and this is it's second visit ..
This time I decided not to search for the crackling noise on one of the channels ..as this would take a long time ..and prove less economical than to rebuild the channel ..
So ..I finally managed to get the schematic and board layout ..so the next step was to source the components ..
roughly 100 ..
A mix of carbon resistors ..transistors and capacitors ..
Well ..few if any original philips caps still existed so originals where possible and modern equivalents if not..
These I gathered from various UK suppliers..
Next the half watt carbon resistors ..
The most economical way to approach this was to buy a 'kit' containing about 10 of each need value ..plus many I didn't need ..
Sourced from China ...as greedy UK suppliers wanted about 4 times the price for the same components.
Finally Transistors..
Luckilly the output transistors could be reused as these would be almost impossible to source ...
which is not to say the others were easy ..
Finally found someone with 'old' new stock in Holland who was prepared to ship me what I needed ..

Having got everything together ...and armed with the schematic I set about rebuilding the amp channel driver board ..
Completed it yesterday ...and on powering up was rewarded with ...errr ..
Nothing .
Turned out the test speaker I had connected to this channel was open circuit ...so borrowed the speaker off the working channel ..
To say that the sound quality is anything other than superb would not be doing it justice..
They certainly knew how to build an amp back then.
Anyone familiar with the Ferrograph name knows it was ascociated with quality ...and the BBC ..
Not reassembled yet ..but another success in the making..
rgds
Evan

 

[Lazarus]

And all you need do now is take a Charge over Nelson's home to cover the cost!

Seriously, well done. Most impressed

 

[sonnetpete]

Really impressed VS. Weren't Ferrograph best known for their high quality (studio?) reel to reel tape recorders?

 

[Vipersan]

Really impressed VS. Weren't Ferrograph best known for their high quality (studio?) reel to reel tape recorders?

Indeed they were Pete ..
The ascociation between Ferrograph the BBC ..and QUALITY was well known at that time ..
Magnetic Tape ..Reel to Reel being foremost I think ..

 

[Vipersan]

...Proper Collectable this Amp ..
2 for sale on fleabay ..
one is on bid ...and I shall be watching it to see what it finally sells for ..
However there is this one ..which granted is in better condition than Nelsons ..physically ...but not guaranteed working....still ..
Vintage Ferrograph F-307 Integrated Amplifier BOXED + MANUAL Made in UK | eBay

 

[Vipersan]

Apparently this amp was first advertised for sale in 1969 ...
Amazing !

 

[Archive7]

Well done on getting the parts.

 

[Archive7]

BTW I have a stock of several standard carbon film resistors (Philips) 1/4 watt somewhere from an old project. Let me know if you need any specific values in the future and I will check if I have them.

 

[Vipersan]

BTW I have a stock of several standard carbon film resistors (Philips) 1/4 watt somewhere from an old project. Let me know if you need any specific values in the future and I will check if I have them.

Thanks mate ..
I already had several of the required values in 1/4 watt carbon ...
..but many of the ones in the amp were rated 1/2 watt ...and I had very few of these ..as they aren't used in TVs these days..
99.9% SMD..
cest la vie

 

[hvdh]

I was going to ask for the circuit diagram, but found it already easily!
Ferrograph Tape Recorders

 

[Vipersan]

Just checked on the auctioned amp on fleabay ..
still 6 days to run ...and already at £99.99
Better look after yours Nelson ..
lol

 

[jeallen01]

Memories! - I kinda lusted after something like that Ferrograph amp in the early '70s but most certainly could not afford it (finally bought a relatively good, and much cheaper, Sansui amp - "2020" IIRC but I am probably wrong - but it was pretty good as far as I was concerned, on credit card (my first EVER cc purchase, and it then took me 6 months to pay that off )). Seriously, Ferrograph was a very respected manufacturer then - great pity that it then went the way it did

 

[Vipersan]

Well ..If repairing this amp was a trip back in time for me ..
I've just watched the first night of Television ...
I swear I just time slipped some more ..
Absolutely incredible that in 80 years we went from flying spots with 200 line scanning to OLED and 3D /4K ..
Mind blowing really ..
Anyone else make the trip ??
rgds
VS
BBC to recreate first night of programming, 80 years on

 

[nelson_b]

The old Ferrograph amp is back in it position here at my place, and performing brilliantly.
(thanks very much Evan)
And its paired up this time with some speakers of the same (1969) vintage.
Celestion Ditton 15