Custom 845 monos w/ Tango transformers

Unison845 · « **Reply #40 on:** 6 Nov 2010, 06:44 am »

Here is a working 845 PPP amp. Preliminary measurement showed that the amp with 1000V on the tube and bias 95ma per tube, it would put out close to 100 Watts, then changed to class AB to 120Watts @5% distortion. It does draw more than 600 Watts from my variac as expected. One more amp to wired!

DrRick · « **Reply #41 on:** 9 Nov 2010, 03:52 pm »

Very nice work UNISON845!

I'd be very interested in learning about your speaker system, including the crossover methodology. I have the intention of building my next system in a manor somewhat similar to yours, although until seeing your system I was thinking of only a 3 way approach; perhaps utilizing push-pull 845's for the bottom.

I had a 3 way system set up about 25-30 years ago, but it utilized commercially made amps (McIntosh MC-275 bottom, Marantz 8B mids, pair Marantz 5's for top). I built a passive filter system with a bunch of UTC inductors, etc. and drove it with a pair of Marantz 1 preamps. That system sits un-assembled and unused in my library these days (where I listen to my IPod Touch-LOL!), except I mis-placed one of the Marantz 1's and used the UTC inductors from the filter in other projects. I'm sure the missing Marantz 1 will show up eventually; I have so much gear that things sometimes go missing for years.

I want to use only DIY electronics in the system I'm building now.

Would you be willing to post some schematics? While I've designed/built 100's of amps I am always looking to learn something new.

Peace,
DrRick

Quote from: Unison845 on 6 Nov 2010, 06:44 am

Here is a working 845 PPP amp. Preliminary measurement showed that the amp with 1000V on the tube and bias 95ma per tube, it would put out close to 100 Watts, then changed to class AB to 120Watts @5% distortion. It does draw more than 600 Watts from my variac as expected. One more amp to wired!

Unison845 · « **Reply #42 on:** 3 Dec 2010, 05:24 am »

Here is the finished pair.

Unison845 · « **Reply #43 on:** 3 Dec 2010, 05:27 am »

It may seemed overkill to power a 2 way speaker with TEN 845 tubes, ... sonically it is well worth it. The eight 845 tubes in the two 845 PP monoblock, brings out the best of the woofers, unbelievable!

Unison845 · « **Reply #44 on:** 21 Feb 2011, 04:30 am »

With the holidays behind, I got to finish the amp, starting with the big tube, Western Electric 212.

James Romeyn · « **Reply #45 on:** 4 Mar 2011, 01:46 am »

WOWWWWWW! Stunning. Love it.

Gopher · « **Reply #46 on:** 4 Mar 2011, 02:16 am »

How much heat do those monos put out? Two 845s is enough to raise the temp in my room.

Stunning build--I bet it sounds great!

poseidonsvoice · « **Reply #47 on:** 4 Mar 2011, 02:50 am »

No words can express my delight at seeing this...

Anand.

Unison845 · « **Reply #48 on:** 4 Mar 2011, 06:52 am »

845 MEET 212e.

The 845 PPP draw about 1300W, the 212 about 800W. Both amps run Class A.

JoshK · « **Reply #49 on:** 4 Mar 2011, 02:08 pm »

Quote from: Gopher on 4 Mar 2011, 02:16 am

How much heat do those monos put out? Two 845s is enough to raise the temp in my room.

Stunning build--I bet it sounds great!

Well if the PPP amps are drawing 650 watts each and putting out 100 watts output, then that means they are putting out roughly 550 watts of heat (each). No need for heater in that room, its got it covered.

JoshK · « **Reply #50 on:** 4 Mar 2011, 02:19 pm »

You're obviously a very skilled builder. How do you heat all those big tubes? Do you get much residual hum on the outputs?

Unison845 · « **Reply #51 on:** 4 Mar 2011, 04:05 pm »

Heater the tube is simple, you just parallel those regulators, on the 212 I used 3 of them. Under the chassis, there are two fans that blow cool air, keeping all the generating heat part cooler for reliability.

JoshK · « **Reply #52 on:** 4 Mar 2011, 04:07 pm »

So you are running DC then. IC.

Unison845 · « **Reply #53 on:** 4 Mar 2011, 06:05 pm »

AC Heater would generate too much hum for 100+db sensitivity speakers.

James Romeyn · « **Reply #54 on:** 4 Mar 2011, 09:00 pm »

Highly recommended (I just did it): Start at the top and re-examine every image in this thread. You just can't believe this is the DIY work of a "hobbyist!" If this is the work of hobbyist, what does professional work look like?

Unison845 · « **Reply #55 on:** 30 Aug 2011, 04:38 am »

Here is my latest. I have to try the 6C33C tube! Latest 6C33C amplifier.

morganc · « **Reply #56 on:** 30 Aug 2011, 05:29 am »

Please shoot me a PM if you decide to "thin the herd"

....I would love to hear one of those beasts.

Unison845 · « **Reply #57 on:** 2 Sep 2011, 01:43 pm »

Sorry... not any time soon. But I can let you borrow if you are local.

Berndt · « **Reply #58 on:** 2 Sep 2011, 05:52 pm »

Ho?
What are you bringing to burning amp?

Unison845 · « **Reply #59 on:** 3 Sep 2011, 06:01 am »

I am not sure that I will go to the burning amp.
If I can make it, I probably bring this 6C33C, since it is lighter than other amp, plus it is a stereo chassis.