NAD: 1978 Hiwatt Custom DR103!!

[OU818]

Oh sorry, did nobody mention these are a bit loud?

No, everybody gave me the impression that I'd have trouble cutting through the mix

[myboss57]

Holy hellfire, that is a beauty man....

[ironlung40]

Oh sorry, did nobody mention these are a bit loud?

No, everybody gave me the impression that I'd have trouble cutting through the mix

Well, that is true from a certain point of view.

[Thinline_slim]

Why did you take it all apart? You just voided the warranty!

Congrats, that thing looks fantastic!

[savage8190]

Man, jealous much...love it!

[Neiloler]

I bet that thing is loud! You could sterilize most small mammals at 50 meters with that setup!

Awesome build inside, that's so much attention to detail. Really cool stuff, congrats! Some day I'm going to pick me up one just to have it.

[a.hun]

I bet that thing is loud! You could sterilize most small mammals at 50 meters with that setup!

Awesome build inside, that's so much attention to detail. Really cool stuff, congrats! Some day I'm going to pick me up one just to have it.

Believe me, if you had one you'd play it too!

Yeah they are like works of functional art, but they are also serious sounding amps too. 'Tonally addictive' you might say. If you back off the mids some they can outFender a big Fender. But at different settings they'll give Marshalls and most anything else out there a real 'doing in' at their own game too. Great tone controls, massive power, tremendous designs and beautifully engineered. Oh and did anyone mention the 'whisper quiet' bit? Very classy indeed - you'd admire it a lot, but you'd also play the hell out of it!


OU818, apart from checking the filter caps there is just one potential upgrade you might want to have done if ever running modern valves. (And I'm guessing you might want to do that - even temporarily - if you have 4 different power valves in it right now!)

The amps only real reliability weakness wasn't really a problem at all when they were made because of the quality of the EL34 valves then available. Those hardly ever failed in such a way as to cause amp damage, but modern ones can sometimes have major shorts which can take out the screen resistors. You can easily prevent this by having the 1W ones upgraded to 5W wirewounds.
See post #15 here:
http://www.thegearpage.net/board/showth ... ght=hiwatt" onclick="window.open(this.href);return false;

Of course if like me you are still only running OS valves and don't want anyone disturbing the paint inside (present on every single original solder joint! ) then it isn't a big worry.


Andy.

[ironlung40]

I bet that thing is loud! You could sterilize most small mammals at 50 meters with that setup!

Awesome build inside, that's so much attention to detail. Really cool stuff, congrats! Some day I'm going to pick me up one just to have it.

Believe me, if you had one you'd play it too!

Yeah they are like works of functional art, but they are also serious sounding amps too. 'Tonally addictive' you might say. If you back off the mids some they can outFender a big Fender. But at different settings they'll give Marshalls and most anything else out there a real 'doing in' at their own game too. Great tone controls, massive power, tremendous designs and beautifully engineered. Oh and did anyone mention the 'whisper quiet' bit? Very classy indeed - you'd admire it a lot, but you'd also play the hell out of it!


OU818, apart from checking the filter caps there is just one potential upgrade you might want to have done if ever running modern valves. (And I'm guessing you might want to do that - even temporarily - if you have 4 different power valves in it right now!)

The amps only real reliability weakness wasn't really a problem at all when they were made because of the quality of the EL34 valves then available. Those hardly ever failed in such a way as to cause amp damage, but modern ones can sometimes have major shorts which can take out the screen resistors. You can easily prevent this by having the 1W ones upgraded to 5W wirewounds.
See post #15 here:
http://www.thegearpage.net/board/showth ... ght=hiwatt" onclick="window.open(this.href);return false;

Of course if like me you are still only running OS valves and don't want anyone disturbing the paint inside (present on every single original solder joint! ) then it isn't a big worry.


Andy.

I fully support competent tech work to make an ancient amp reliable. If it is going to be played and not put in a glass case, this is really necessary. I had the screen resistors on my OR120 changed to to cushion the tubes a bit, just because I know the current production one's aren't as robust. It was a small insurance for better reliability. I can always return it stock.

[OU818]

I cranked it a bit more today and discovered something I didn't want to discover. My amp is subject to blocking distortion, known as fizz, that a number of the 2 input Hiwattswere subject to. So as much as I like the paint work, I'm going to mod the v2 circuit to be the same as the mid 70s. May as well change the screen resistors while I'm at it.

[a.hun]

Um, thats a pity. I wasn't aware of that problem, but you've clearly been doing your research and found the info from Hiwatt 'guru' Mark Huss on that:
http://hiwatt.org/2_mod.html" onclick="window.open(this.href);return false;

FWIW here is his original post on the Hiwatt Convention forum:
http://www.vintagehiwattconvention.com/ ... distortion" onclick="window.open(this.href);return false;

Amazing that it only seems to have been discovered four or so years back. Still, at least it is easily sorted by a tech given the right info.

Yeah, don't forget to have the filter caps checked too while the tech is in there.


Andy.

[OU818]

I'm now not sure that it is what's wrong with the amp.
The sound is occurring even with pedal overdrive

[ironlung40]

I'm now not sure that it is what's wrong with the amp.
The sound is occurring even with pedal overdrive

with vintage amps comes maintenance. I wouldn't worry about that too much, yet. I'd just have a tech give it a once over. It could be something very simple. It might just be the caps.

Just trying to brighten your day a bit. That is a great amp you lucked into. It is worth doing a little sorting on it to get it 100% healthy.

[OU818]

Right... I'm pretty sure it may be the cab.
As good as it is that the amps probably fine, I'm upset that the cab full of Fanes may be dead.

Gonna try another cab tomorrow.

[ironlung40]

Right... I'm pretty sure it may be the cab.
As good as it is that the amps probably fine, I'm upset that the cab full of Fanes may be dead.

Gonna try another cab tomorrow.

I didn't think of that. You think it is coil rub? We need some audio of this.

[OrangePaul]

You could price up having the speakers re-coned if that's the problem...
Maybe it's just one out of the four