SE DR103

Vox and Hiwatt Discussion

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statorvane
Posts: 556
Joined: Thu May 11, 2006 3:28 pm
Location: Upstate New York

SE DR103

Post by statorvane »

Not sure what to call this one. It is essentially a Hiwatt DR103 preamp driving a parallel single ended power amp. It is a really good sounding amplifier, possibly the best I have attempted. The tone stack is a lot different than the typical FMV stack. Here is a photo: [img:1024:768]http://i165.photobucket.com/albums/u76/ ... 6dplq3.jpg[/img]
with links to the album, including some gut shots:http://s165.photobucket.com/user/JKCavi ... t=3&page=1

Now, I've got to build a cab for this puppy.
sunnydaze
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Re: SE DR103

Post by sunnydaze »

Great looking amp. Love the face and back plates, very tidy inside. Would love to hear some clips.

Mike
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statorvane
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Re: SE DR103

Post by statorvane »

Thank you for the compliments. The face plates are some I generated in LibreOffice's Power Point clone and had printed at Stales. They have an outdoor vinyl that is pretty sturdy. They are protected by some plastic sheets I got at Lowes or HD.

I'll ask my son to post some clips or a link to them. He uploaded several clips to his Facebook page.

I've attached a schematic for those who may be interested. I still have to document the OT wiring to the speaker jacks. I have the primaries wired in parallel, but the secondaries are wired in series. I complicated this by providing a selectable pri impedance (2.5K to 5K Ohms) and two secondary impedances (4 Ohm and 8 Ohm).

I also added a DPST switch to select a "late 60s" or an "Early 70s" biasing scheme for V1. Frankly the Late 60s is the best; Late 70s really bright. Never enough switches!

Time to build a head cab for this one.
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statorvane
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Re: SE DR103

Post by statorvane »

Found an error in the schematic - tonestack. the 1n cap to the bass pot ground should be 47n, not 1n.
Synchu
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Re: SE DR103

Post by Synchu »

It is rather fashionable these days to bring up old threads so I'll make no exception.

Very nice looking build is this and I'm getting the itch to go after it. Now that some time passed, does someone else tried this one?
Sound sample will be more than appreciated as alway.
Niki
joeboo88
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Re: SE DR103

Post by joeboo88 »

That's one cool schematic, thanks for bringing this to our attention, synchu
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