Help Finding Amp Info

Doodlegame

Hey,
We have a Hohner amp but don't know anything about it, seems to be a one of a kind. Asked Hohner about it, amp specialists and Honer suppliers etc. Only things we have found have been a picture of it on an advert pre-decimalisation and that the control panel looks similar to that of a Fenton Weil amp which we found a fuzzy photo of.

If anyone thinks they would be able to identify the valves we need to repair it too I'll upload a pic if you let me know

Cheers

Doodlegame

Doodlegame

  

ICBM

Can you take a pic of the valves? Do you know for sure any of them are dead?

The amp is likely to need other work too, and in fact the valves are *less* likely to be the problem than some other parts, especially electrolytic caps.

I would certainly not assume that changing the valves is either necessary or will fix it, without more info. Preferably, don't even turn it on - if it hasn't been run for a long time it could do damage to itself that can be avoided if it's powered up more carefully.

Apologies if you know all this already!

Doodlegame

ICBM said:

Can you take a pic of the valves? Do you know for sure any of them are dead?

The amp is likely to need other work too, and in fact the valves are *less* likely to be the problem than some other parts, especially electrolytic caps.

I would certainly not assume that changing the valves is either necessary or will fix it, without more info. Preferably, don't even turn it on - if it hasn't been run for a long time it could do damage to itself that can be avoided if it's powered up more carefully.

Apologies if you know all this already!

That is just what my dad told me I think he turned it on and it sounded noisy or something. I don't have a picture of the valves but I'll try to get some more of the internals later and post them.
What do you mean don't turn it on it could damage it? How do you tell or is it just a check everything first kinda thing?

Thanks

ICBM

Too late if he already turned it on. If it hadn't been used for a long time, just powering it up can sometimes blow electrolytic caps. It's much better to power it up slowly with a Variac while monitoring current draw and internal voltages. But if smoke didn't come out you've probably got away with it...

Noise may or may not be anything to do with the valves. It could be as simple as corrosion in the valve sockets, or moisture in carbon-comp resistors, or failing caps - in fact at the age it is, replacing all the electrolytic caps would be a good idea whether or not they're the cause. Unless any of the valves is visibly cracked or white where it should be silver, assume they're good until proven otherwise.

If that's the mains power connector on top, it should also be replaced really - TAD do a good modern IEC socket which fits very well. It may not be original anyway, that would be a rather odd place for it.

ToneControl

I had some working valves from ww2 (or shortly thereafter). They can last a long time

Doodlegame

ICBM said:

Too late if he already turned it on. If it hadn't been used for a long time, just powering it up can sometimes blow electrolytic caps. It's much better to power it up slowly with a Variac while monitoring current draw and internal voltages. But if smoke didn't come out you've probably got away with it...

Noise may or may not be anything to do with the valves. It could be as simple as corrosion in the valve sockets, or moisture in carbon-comp resistors, or failing caps - in fact at the age it is, replacing all the electrolytic caps would be a good idea whether or not they're the cause. Unless any of the valves is visibly cracked or white where it should be silver, assume they're good until proven otherwise.

If that's the mains power connector on top, it should also be replaced really - TAD do a good modern IEC socket which fits very well. It may not be original anyway, that would be a rather odd place for it.

Ok thanks

We'll try to get it working and find out some more about it..

57Deluxe

@Doodlegame post this over at the Hofner Hounds Fourm

https://www.tapatalk.com/groups/hofnerhounds/amp-talk-f20/

Gadget

So hold on, is this a Hohner or a Hofner ?

Doodlegame

Gadget said:

So hold on, is this a Hohner or a Hofner ?

Sorry for slow reply, It's a Hohner

Doodlegame

57Deluxe said:

@Doodlegame post this over at the Hofner Hounds Fourm

https://www.tapatalk.com/groups/hofnerhounds/amp-talk-f20/

I'll try that, thanks ☺️