Yup and I did give it a good look through but failed to find the particular amp. One of my friends from the BBC remembers them though but has no idea of their identification details. They certainly were never cased not did they have any controls at all - just a bare bones amp chassis - they came in a cubic cardboard box with loads of packing and little else.
H&H power amp
- Thread starter Joddle
- Start date
Yup and I did give it a good look through but failed to find the particular amp. One of my friends from the BBC remembers them though but has no idea of their identification details. They certainly were never cased not did they have any controls at all - just a bare bones amp chassis - they came in a cubic cardboard box with loads of packing and little else.
Thanks for that - but still no although maybe we are getting closer
The power conenctions were via a small bulgin socket. The chassis were always matt black as they ware also the heatsink althougn no fins attached. The output transistors were T03 cased with two per side of the U formed chassis they were complimentary darlingtons with an HH id number so they real tyupe could not be easily identified - the TO3 cases had slightly bulging dull aluminium tops unlike a 2n3055 whcih had bright smooth flat tops.
demotivated
pfm Member
They definitely sound like MOSFETS/V-FETS etc. Or something Jap/US made - Delco??
Try DTS 411
Try DTS 411
Thank heavens for the Internet - through it I managed to speak with someone who does remember everything about the amps in question. They date from early on apparently.
They were I am told not a Mike Harrison design yet were manufactured by HH. Origionally the circuit and board for the amp was used in the TPA50 so it seems my memory about Darligtons for the outputs is flawed.
At the time HH produced a dual amp chassis based on the TPA25 for the BBC to use to drive monitors with each chassis providing spearate amplification for the bass units and tweeters - HH followed this up with a beefier version using two TPA50d boards powered by a common power supply based on the transformer from a TPA100 this being the amp I had all those years ago.
The amps were nominally rated at 50w into 8 ohms but with sufficient additional cooling could operate down to 4 ohms where they would give about 100w per amp - ie a 200w slave if using both amps on the one chassis.
Well now I know - and so all I have to do is find one.
They were I am told not a Mike Harrison design yet were manufactured by HH. Origionally the circuit and board for the amp was used in the TPA50 so it seems my memory about Darligtons for the outputs is flawed.
At the time HH produced a dual amp chassis based on the TPA25 for the BBC to use to drive monitors with each chassis providing spearate amplification for the bass units and tweeters - HH followed this up with a beefier version using two TPA50d boards powered by a common power supply based on the transformer from a TPA100 this being the amp I had all those years ago.
The amps were nominally rated at 50w into 8 ohms but with sufficient additional cooling could operate down to 4 ohms where they would give about 100w per amp - ie a 200w slave if using both amps on the one chassis.
Well now I know - and so all I have to do is find one.