Half power switch on DR103

[loupmanaut]

Hello,
I'm new on this forum.
I just bought a Hiwatt custom 100 DR103 from 1976 with a wem cab ( 1972 sound city with fane, customed to gilmour wem cab). The DR103 is in perfect condition, Harry Joyce signed. I'd like to add a half power switch like the ronnie wood amp ( through the extreme left hole in the rear chassis). Is somebody owned the original half power switch wiring layout ?
I will post picture of the amp tomorrow...

Thanks

[loupmanaut]

[loupmanaut]

UP

Does anyone done this mod (half power switch ) ?

Thanks

[mikhailwatt]

Hello,
The DR103 is in perfect condition, Harry Joyce signed. I'd like to add a half power switch like the ronnie wood amp ( through the extreme left hole in the rear chassis).

Hi - I believe it's a very simple mod.

However... most here would strongly advise against modding a perfect condition '76 Hylight HIWATT, even utilizing an existing hole.

Michael

[Dr.HI-TONE]

I agree with Michael.
it is ill advised to do to a pristine vintage HIWATT.

[OldSchoolDave]

As an alternative to modding - and, since one can't/shouldn't throw a Half Power switch on the fly - if you want to run your DR103 at approximately 50 watts, simply pull the outer pair of power tubes and half your impedance selector setting.

For verification of this approach, scroll down the page at this link: http://hiwatt.org/FAQ.html

Dave

[Dr.HI-TONE]

The small faces amp with the half power switch also has a Fender/Marshall tone stack, so it would be a waste of time and effort to focus on minute details like a half power switch when trying to recreate that tone.

[loupmanaut]

Thanks guys about your advice. I'm gonna try to pull off the outler tubes and no mods on this "perfect" amp.
I have not yet tried my Ho's attenuator with this amp. This attenuator works fine with my 1967 100w jtm45 and my 1964 fender vibroverb clone.

Thanks !!!

[mikhailwatt]

I have not yet tried my Ho's attenuator with this amp. This attenuator works fine with my 1967 100w jtm45 and my 1964 fender vibroverb clone.

I used an Ultimate with my DR103 clone for awhile - worked pretty well at reasonable attenuation levels.

[loupmanaut]

The Ho's attenuator = ultimate attenuator + all options !!!
M. HO is the inventor of the UA. He can build UA with all options. Mine works fine with all ohms Amps (2 to 16 ohms).

[mikhailwatt]

The Ho's attenuator = ultimate attenuator + all options !!!
M. HO is the inventor of the UA. He can build UA with all options. Mine works fine with all ohms Amps (2 to 16 ohms).

Yes, little old gentleman in Vancouver, I believe.

I found that it was necessary to bypass the inductor coil (mine didn't have a "plexi" switch) otherwise it sounded painfully bright with my DR. YMMV!

[loupmanaut]

I didn't use the plexi switch...
I have the 100w amp model (can be used with amp from 2w to 100w)
I use it at home (recording, just playing and on stage)
The only limit of the attenuator is when the sound of your amp is :
20% the amp and 80% the speaker, like my supro because the speaker had to be shake up to obtain THIS sound.

Yes Ho is from Canada :
His website:

http://hoelectronics.com/wordpress/

Very nice person, very hepfull.

[mhuss]

Ho's workspace looks like mine, but his is less cluttered.

A lot of people love these, but I have never been a fan of the attenuators with solid-state amps on the back end. If you turn it up too much, it starts to sounds like SS distortion.

--mark