Canadian Mod

HIWATT amps from the Hylight Electronics era

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mikhailwatt
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Re: Canadian Mod

Postby mikhailwatt » Mon Nov 02, 2015 1:26 pm

therealjoeblow wrote:I'm still finding it a bit brighter than I would like, and without adding any radical additional mods...

...Or is this on the wrong track?

Of course, everyone has their own "ears" for these things... but I find my de-modded '80 DR504 to be anything but overly bright.
Have you experimented with preamp valves? The right V1 can make a huge difference.

"YMMV"
You can almost feel the current flowing
You can almost see the circuits blowing

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mhuss
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Re: Canadian Mod

Postby mhuss » Mon Nov 02, 2015 6:43 pm

I was just looking at the pictures, you might want to insulate the far end of the 220k resistor; I don't like the high voltage 'flying' like that with no support.

--mark

therealjoeblow
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Re: Canadian Mod

Postby therealjoeblow » Thu Nov 26, 2015 1:04 am

It still has the factory original Mullards in the preamp. They were tested by the tech who did the recap for me a few months ago, and he said they are pretty much as-new.

In hindsight, I don't think any additional mods are required ... I was following conventional logic when trying to dial in a good tone, which is generally to set everything to noon and tweak from there. Doing that with treble, middle and presence made it sound still too bright. And 'moderate' tweaking didn't seem to be able to tame that. So in frustration I set everything except for bass to zero, and suddenly found the high end and upper mids were then way closer to what I expected! A bit more tweaking on the presence got me there.

In the end, I landed on the following:

Normal & Bright Volumes bridged with a y-adapter
Normal at noon (any more gets a bit too muddy in the low end)
Bright at full
Bass at 3:00 (ie, 3/4 of max)
Treble at 7:00 (ie, off)
Middle at 7:00 (ie, off)
Presence at 3:00 (ie, 3/4 of max)

And that's working very well now! Getting me a real nice Malcolm Young crunch at drummer levels; and pushing it with a Hardwire CM-2 overdrive with level set to noon and gain set to zero gets me to classic rock and 80's tones.

@Mark - thanks for the suggestion - I don't think it will go anywhere though, that blue wire is a 14ga solid core, it's very stiff, and the solder joint is pretty good between it and the resistor. But in the interests of safety, perhaps a bit of heatshrink is a good idea.

Otherwise, I'm pretty happy to leave it the way it is now, I haven't really done any major intrusive mods that should affect its value, and if wanted back to factory, it's basically just removing the extra cap and 2 resistors at V2.

Cheers
TRJB

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OldSchoolDave
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Re: Canadian Mod

Postby OldSchoolDave » Thu Nov 26, 2015 1:47 pm

therealjoeblow wrote:It still has the factory original Mullards in the preamp.


Mullard ECC83's (& ECC81's) can last a very, very long time. I've owned several Hiwatts that had original-looking Mullard and BRIMAR pre-amp tubes.

It's the power tubes that have a shorter life expectancy in Hiwatt amps.

Glad to hear you got things sorted out to your liking!

Dave
...Hey! I played that song when it was new...

http://www.OldSchoolDave.com

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mikhailwatt
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Re: Canadian Mod

Postby mikhailwatt » Tue Dec 01, 2015 1:30 pm

Not familiar with your Eminence speakers but, based on past experience with different speakers and tone settings, these beasts really shine (in a good way - not too bright) when paired with their old Fane mates. Nowadays I normally run my tone knobs all around noon or a bit higher. "YMMV"
You can almost feel the current flowing
You can almost see the circuits blowing


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