Rare CP103 amp on Ebay

[shakti]

I missed this one, but interesting to see what looks like a stock CP103 spec amp from the late 70s:

https://www.ebay.co.uk/itm/Hiwatt-DR-10 ... 7675.l2557

[shakti]

When it rains, it pours....here's another one!

https://reverb.com/item/35114883-hiwatt ... end-dr103w

What do the experts make of this? I *think* I see marks from a star washer under the extra preamp hole which makes me think it could have started life as a PA amp, but I'm not sure. Also, this one has the late 70s phase inverter. The experts will know better than I do, but isn't 1974 a little early for that?

[Dr.HI-TONE]

I would ask for several more pics of the one on reverb.

[mhuss]

There are clearly wear marks on the 'unused' tube hole. It's probably (as you guessed) a PA conversion. I must say, it's a very good one!

FWIW, this one (5075) and 5073 are in the registry as 'W's...

[shakti]

Yeah, if it is a fake, it is a rather good one. The faceplate is also a little odd - if a fake, why not make one with «The Who» labeling? I don’t think I’ve seen that variation on the 4-channel faceplate before.

[shakti]

Another slight oddity; shared cathode resistor and cap for V1 and V2. Not something I've seen in any other CP103. I'm confused about this one, many things point to it being original (circuit or faceplate not copied directly from any other known variations, preamp board and wiring style looks very good and original to my eyes), but that extra preamp hole looks to have wear and marks from a previous preamp tube.

Logo is also placed a little oddly. Should be pretty easy to identify in photos of Who amps from the mid-70s.