this is Martin from Stuttgart/Germany. I play in a Stones-Tributeband, taking the parts of Brian, Mick and Ronnie. On stage I’m using a 1969 JMP50 or a 1966 BF Dual Showman, together with an Aracom Attenuator and a 4x12 with Pre-Rolas. This works pretty well ☺ - however, recently I had the chance to get a Hiwatt DR 103 from probably late 1971, Serial Number 2491 with some (minor) issues, and a front loaded 4x12 with these white dust cap Fanes - and that’s what gets me here now. This is a great forum, I definitely got hooked on these amps now, read a lot already – and will be reading a lot more I guess... ☺ Hope that I can learn more about these amps here and share my knowledge in this forum.
Here are some pics:
The amp works quite well already – however, I won’t use it until it is completely serviced and checked. It came with four Hoges tubes in the preamp and four selected EH EL34 tubes in the power section. Two pots and the mains switch had been replaced. New power cord. Input jacks are rewired. Some work in the power section had been done... But most of the solder points in the amp still have some golden dye on it. That’s what I see so far. I haven’t checked the voltages yet. At first, I had to remove some black paint which somebody put on the outside of the chassis for whatsoever reason... Next thing will be a cap job and checking the soldering connections and grounding – the bolt near the input jacks is loose and still covered with paint . I’m thinking about an adjustable bias too - as it probably won’t be easy to find some affordable NOS Mullards.
The preamp looks ok to me. V1B coupling cap and the tone stack cap Treble 1 are RS instead of Mustards. Tone stack cap Treble 2 is a ceramic.
Now to the power section:
I'll replace those green 10R resistors with 1R for proper biasing and remove the diodes on the tube sockets.
What would be the appropriate value and wattage for screen resistors?
There’s an additional brown 330 ohms resistor paralleling the 1k resistor located right in the middle of the turretboard, right next to the UF 5408 diode...
picupload
Do you see anthing else crucial or worth mentioning?
Regards
Martin
(posted also at the PP-Forum)
