Opinions on Yamaha C-50 Pre amp...

LowVoltage

The little round Irishman
Picked up a really clean cosmetically and electronically C-50 for $20. Lotsa info on the C-6-,65's etc. Not much on the C-50 tho. Do not know where it falls in the pecking order. If even if it's a keeper. sounds fine on my SAE MKII and Kenwood power amps, nice and clean.

Additionally can anyone explain, in layman terms,what the hell those 'Bass and Treble Turnover controls do? I also have switch settings on a HK integrated. Where do you set them as a starting point?

ANY info/opinions appreciated

Mike
 
The turnover controls change the frequencies at which the bass and treble start their effect. [jedi mind control] And you don't want this pre-amp, you want to send it to Canada...[/jedi mind control]
 
Early 1980s. I would think it was second to the C-70.
Yamaha preamps are very quiet, they very much disappear.
 
I have this preamp but haven't used it much as it has been at my tech's for a while now and I didn't have it long before then.
Like Bully said, very clean, very quiet, not their best by a ways but if you like it you like it :thmbsp:
 
bully is right on, 1982 in the line up with the C-70. MSRP $530.

Sound wise good, but not quite in league with the 60, 65. My brother has one but got quite surprised by difference to the C-85 that I gave him; there is a clear difference in sound quality (His setup was C + M-50). Still I believe it to be better than the C-4 and C-6.

The phone stage is one of it's week points compared to the newer Yamaha pre's (post C-60).

The tone control is called a parametric EQ and the freq. knob indicates the center of attack. It has been covered in the forum.

It is a good pre and at $20 it is save to call it a real steal (almost a robbery).
 
I have a C-50 and it gets very very hot when operating; is that normal for this preamp or have I got one that needs looking at?
 
Hi Thudd - I just found this thread. I picked up a C-50 preamp a few weeks also, and it runs very hot as well. Mainly the transformer and the two heat sinks next to it. Also, on mine, the right channel has weak output, and when I pushed on the relay leading to the pre-amp out, the volume comes back. Has anyone responded to you, or have you found out if that was normal? Thanks.
 
Also, on mine, the right channel has weak output, and when I pushed on the relay leading to the pre-amp out, the volume comes back.

Sounds like a case of dirty relay contacts. A shot of contact cleaner like deoxit on the contacts should fix the weak output. Post in the DIY forum with photos of the relay and they should be able to help.
 
Sometimes you got to get more aggressive on the relay contacts, a little fine emory cloth.

My C-4's both run hot, it's normal. Just give it more breathing room than a cool pre--no stacking or tight enclosures.
 
I was wondering how to take off the clear cover on the relay and whether to desolder it first, since I am all new at this. But pressed on the clips, off came the cover, did the fine sand paper, and Deoxit the innards, and now it sounds great. Thanks everyone!
 
Sometimes you got to get more aggressive on the relay contacts, a little fine emory cloth.

My C-4's both run hot, it's normal. Just give it more breathing room than a cool pre--no stacking or tight enclosures.

I also have C-4 and recently heard from a friend that preamp work in pure class A, and I assume that the same situation is with the other Yamahas. So, it should be quite normal to run hot.
 
Have a excellent sounding Yamaha CX-830 Preamp and it too runs pretty warm during use. Like others said, give it some room.
 
Dammit..I hate it when someone revives a old thread and I don't catch it..:D Good for the post count though..
 
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Also, on mine, the right channel has weak output, and when I pushed on the relay leading to the pre-amp out, the volume comes back.

Sounds like a case of dirty relay contacts. A shot of contact cleaner like deoxit on the contacts should fix the weak output. Post in the DIY forum with photos of the relay and they should be able to help.

Ah! that sounds like what I need to do, except that the output is only wonky when I use the phono inputs. The volume is either quiet or unbalanced. Anyone with experience of that problem on a Yamaha C-2 (or other ) Pre-Amp? Doesn't look like the relays are openable.

Pic of the relays from Amp8
 
Necro bump!

My C-50 developed a problem where one channel would intermittently drop out, or would become scratchy with slightly lowered volume.

I took it to the repair shop armed with the info from this thread, and a couple of relays later and a repair bill less than a reasonable restaurant meal it is as good as new again.
 
Necro bump!

My C-50 developed a problem where one channel would intermittently drop out, or would become scratchy with slightly lowered volume.

I took it to the repair shop armed with the info from this thread, and a couple of relays later and a repair bill less than a reasonable restaurant meal it is as good as new again.

Yup...the C50's seem to have that problem.
 
In the C-50 some were fitted with open relays (top can be removed) and some were sealed ,
I have 2 C-50s one has sealed relays the other which did not, so I have replaced them all with the sealed ones which don’t give any problem
 
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