Hiwatt dr-201 four output schematic

[wallsofsound]

I gave a schematic of Mark Huss's dr-201 output section a while back to Blackie Pagano( well known local amp tech) and he indicated to me that the schematic was wired for four parallel outputs? Thought this was strange because I know in the faq it usually says that some need an extra dummy plug if used for one cab alone.

What would happen if an extra plug was not used( no sound, less sound). I have asked something similar to this before on this board, but I recently tried a Fernandes era Dr-201 with only one cab and no dummy plug that was pretty quiet compared to mine.

This was the 1975 dr-201 before being modded to the M. Huss schematic:


After being modded following schematic for four kt-88 dr-201 output section M. Huss site(Blackie Pagano identified as parallel outputs):


These are both kinda weird cuz I often see this for a usual four kt-88 outputs under chassis:




Mark Huss or any other HIWATT snob if you are out there and can give a hand please feel obliged to do so!

thanks!
Wallsofsound

[mhuss]

The schematics are based on representative samples that i had available at the time I did them several years ago, they are what they are.

If you prefer the bizarro connection that requires the jumper plug, it is shown on the 6xEL34 version.

--mark

[Stu_R]

Loosely related so I didn't think worth a new thread (aren't you glad - it's still Slade ) but I thought you tech guys may be interested in this.

Noddy Holder & Dave Hill, (rhythm & lead guitar respectively) both had identical Hiwatt stacks consisting of a DR201 with a 100w on top of each. These powered 4 x 4122 cabs for each person.
On top of the column next to them they each had duplicate cabs, powered up but with no cab connection . The reason being (I was told by their tour manager & by Dave) was that if a tube/fuse blew mid gig is was an easy job for the crew to kill the amp & switch the cabs' leads over to the spare amps in seconds.

All of their 201s (bassist Jimmy used 5 of them) had the same rear mods as mine has DI & slave out; apart from Noddy's newer 1977 spare 201. I've been told that it has a mod to make it safe to have it switched on with no load (possibly the reason why his older one "blew up").
While I was helping my mate who now owns it clean it up I took this pic, which I dunno if it shows any such mod or not.