[Oya?]

Hi HF,

I bought a Millet hybrid from here very recently and I want to install a power switch, because it doesn't have one. I've got some tools but absolutely no DIY or electronics experience really (never soldered anything) so I'd really appreciate any help, and apologies in advance for the really newbie questions.

I did a search here so I think I sort-of understand what I need to do, There's a black and a red wire going to the power jack, I'm supposed to desolder the "hot" (red?) wire from the power jack, solder that to one of the two terminals on the switch, and then wire the other terminal back to the positive terminal on the jack?

I bought a SPST rocker switch from a store, it's got two terminals and one's shorter than the other; I don't know if that means anything though.

And I need to drill a hole in the rear end-plate for the switch. Does it need to be a really tight fit? Does it need to be threaded? I've got a stepped drill-bit; if I attach it to a hand-drill I should be able to go through aluminum no problem right?

More importantly though, is there anything else besides the switch that I need to add to the amp itself? Like any resistors or caps or what-not. I looked up the archived parts list and I don't think there's anything important missing, but I can see a few empty/bypassed spaces on the PCB.

Thanks for reading.

 

[tomb]

Quote:

Originally Posted by Oya? /img/forum/go_quote.gif Hi HF, I bought a Millet hybrid from here very recently and I want to install a power switch, because it doesn't have one. I've got some tools but absolutely no DIY or electronics experience really (never soldered anything) so I'd really appreciate any help, and apologies in advance for the really newbie questions. I did a search here so I think I sort-of understand what I need to do, There's a black and a red wire going to the power jack, I'm supposed to desolder the "hot" (red?) wire from the power jack, solder that to one of the two terminals on the switch, and then wire the other terminal back to the positive terminal on the jack?

Sounds like you understand the scenario quite well.

Quote:

I bought a SPST rocker switch from a store, it's got two terminals and one's shorter than the other; I don't know if that means anything though.

Probably not ... but it sounds a bit unusual - is this a lugged switch or does it have pins for a PCB? Switches for a PCB are sometimes bent at a 90-degree angle for soldering on a PCB. One pin is longer than the other to facilitate the bending.
Quote:

And I need to drill a hole in the rear end-plate for the switch. Does it need to be a really tight fit?

only tight enough so that the hole doesn't show

Quote:

Does it need to be threaded?

No. Quote:

I've got a stepped drill-bit; if I attach it to a hand-drill I should be able to go through aluminum no problem right?

If you mean hand-power-drill, then yes.
Quote:

More importantly though, is there anything else besides the switch that I need to add to the amp itself? Like any resistors or caps or what-not. I looked up the archived parts list and I don't think there's anything important missing, but I can see a few empty/bypassed spaces on the PCB.

The old revMH Millett Hybrid PCB had two choices for CCS - either D2LA or D2LB. So, one each of those spaces will be empty. If it was Rev.2 of the revMH Millett Hybrid PCB, then there will also be two options on the board for output buffers - DIP-8 socket positions, iow. One was for BUF634/OPA551, the other for the Intersil HA-5002. So a pair of those will remain empty under normal circumstances. Note, however, that you can solder the sockets in both positions and then swap one pair for the other if and when you want.

Depending on which pot was used - Alps RK27 or Panasonic EVJ, then the other pads will remain empty. Some did not install the panel LED and resistor - those pads could be empty. Also, the output resistors, RB14L/R, were optional, but the pads have to be jumpered if those weren't used.

Finally, there are several terminal block positions. Depending on which ones were used, the others would remain empty.

Quote:

Thanks for reading.

More info here: Millett Hybrid Headamp

 

[Oya?]

tomb, thank you very much for the help! The switch is a lugged one; I'm gonna try to install it after I get some hook-up wire because I forgot to buy some.

 

[Oya?]

I got it installed; my solder work is embarassingly sloppy and I burned myself several times (and also the carpet, just slightly; yes I was working on the floor) soldering the rear jacks back together but it's all done and working perfect and I didn't mutilate the amp in any way.

It's such a small job for you tomb and a lot of others here but I'm the kind of person that always manages to make things worse when I'm trying to fix or change something, so I'm really greateful for the help!

BTW this is the Millet that I bought. I put the switch on the back because 1) it's so much easier and 2) because Mat put such a pretty frontplate on it that I didn't want to mess it up (the reason I bought this one instead of the other Millets in the FS section).

 

[tomb]

Quote:

Originally Posted by Oya? /img/forum/go_quote.gif I got it installed; my solder work is embarassingly sloppy and I burned myself several times (and also the carpet, just slightly; yes I was working on the floor) soldering the rear jacks back together but it's all done and working perfect and I didn't mutilate the amp in any way. It's such a small job for you tomb and a lot of others here but I'm the kind of person that always manages to make things worse when I'm trying to fix or change something, so I'm really greateful for the help! BTW this is the Millet that I bought. I put the switch on the back because 1) it's so much easier and 2) because Mat put such a pretty frontplate on it that I didn't want to mess it up (the reason I bought this one instead of the other Millets in the FS section).

Glad to hear you got it fixed and running!!

Just to set the history straight, that Millett Hybrid was built by one of the best - Steinchen. he was one of the earliest builders of the revMH Millett Hybrid and went on to design the Diamond Buffer PCB's that were used to plug into the Millett Hybrid.

You can find this one and many more of his amp builds here:
Audio DIY Inventory - tube amps

 

[Oya?]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Glad to hear you got it fixed and running!! Just to set the history straight, that Millett Hybrid was built by one of the best - Steinchen. he was one of the earliest builders of the revMH Millett Hybrid and went on to design the Diamond Buffer PCB's that were used to plug into the Millett Hybrid. You can find this one and many more of his amp builds here: Audio DIY Inventory - tube amps

Wow, I didn't know this amp had a history.

I just sorta assumed that Matez made it! Guess it's a good thing I didn't mess it up huh? And thanks for the link, I'll have a look at his gallery!