Custom 845 monos w/ Tango transformers

Unison845 · « **Reply #60 on:** 7 Sep 2011, 05:13 am »

For source, I'll bring my Wireless DAC/Preamp, the the one in the middle, the same one I brought last year.

Unison845 · « **Reply #61 on:** 26 Apr 2012, 05:16 am »

Latest 6C33C SE mono block amp with purpleheart hardwood chassis.

morganc · « **Reply #62 on:** 28 Apr 2012, 07:46 pm »

Quote from: Unison845 on 2 Sep 2011, 01:43 pm

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

Thanks for the generous offer. I just found your response. Where is local? I'm in San Francisco.

tull skull · « **Reply #63 on:** 28 Apr 2012, 08:12 pm »

Unisom I just wanted to say that I really admire you for all your talent and appreciate taking the time to share it with us...Oh yea, I also hate your gutz!

Unison845 · « **Reply #64 on:** 30 Apr 2012, 04:22 am »

I live in Fremont, about 40 miles from San Francisco.

Quote from: morganc on 28 Apr 2012, 07:46 pm

Thanks for the generous offer. I just found your response. Where is local? I'm in San Francisco.

Unison845 · « **Reply #65 on:** 30 Apr 2012, 04:32 am »

Tull Skull,
I appreciate your comments, it's much harder to make an amplifier look pleasing the eyes than to design a tube power amp I think. Took me more than 2 months to get the chassis layout to the point that I like. It only takes me 3 days to make this GM70 amp sing from scratch. Here is my latest GM70 amplifier also in purple heart hardwood chassis.

Quote from: tull skull on 28 Apr 2012, 08:12 pm

Unisom I just wanted to say that I really admire you for all your talent and appreciate taking the time to share it with us...Oh yea, I also hate your gutz!

morganc · « **Reply #66 on:** 30 Apr 2012, 09:22 pm »

Quote from: Unison845 on 30 Apr 2012, 04:22 am

I live in Fremont, about 40 miles from San Francisco.

Wow! I've wanted to start some DIY and it is nice to know that I've got such an expert locally. I would be thrilled to connect with you sometime this summer when my work settles down a bit. We have so many audiophiles in the Bay Area and I have greatly enjoyed making friends along this journey. Thanks again for the kind offer.

Unison845 · « **Reply #67 on:** 1 May 2012, 01:30 pm »

DIY is lots of fun, but playing with high voltage is deadly dangerous!

I think everybody who build amplifier got shock from it at least once. For my part I got it more than once, but the most memorable one happened when building a 250TL (20 years ago) amplifier with voltage about 1000V, the amp is very heavy since it is a stereo, probably over 100lbs so moving around was not easy. I got the amp up side down to debug something, then I turned the amp power off and tried to reach a long nose plier, my arm part close to the elbow touched the 4 pin socket and gave me the hardest electrical shock in my life, my heart beat irregularly, i can feel my hair raised straight, and for six moths period, I did not touch that amp, that's how scary it was. I was lucky because the power amp was OFF, it was only the discharge of the storage cap through my arm that gave the shock, so I dont want to think what would have happen if the amp was ON. I also heard of a story that a guy who tried to build an 845 amp that lost a finger. Luckily, with tremendous caution since then, I have not got any shock from amplifier building. But as always, powering a freshly built power amplifier such as the GM70 with 1400V under the chassis for the first time always make my heart racing!

So, while DIY is fun, I would suggest any starter to proceed building high voltage stuff with lots and lots of precaution, sometimes it might be worth it to pay somebody to build an amp for you rather than taking chances, especially if you own quite a few Apple or Google stock. Starting DIY in other area such as speakers, DAC, turntable are also lots of fun but much less dangerous.

Quote from: morganc on 30 Apr 2012, 09:22 pm

Wow! I've wanted to start some DIY and it is nice to know that I've got such an expert locally. I would be thrilled to connect with you sometime this summer when my work settles down a bit. We have so many audiophiles in the Bay Area and I have greatly enjoyed making friends along this journey. Thanks again for the kind offer.

JoshK · « **Reply #68 on:** 1 May 2012, 02:41 pm »

There is some great info on electrical safety on tubelab's site. I think he worked on telephone poles at one point and is a power engineer by day.

I like how he suggests plugging the amp into a power strip some distance from the amp, pre-hook up lots of DVMs with alligator clips prior to power up and if using electrolytic caps at high voltage protect yourself behind a clear plexiglass barrier, then turn it on and read the voltages, power down and wait till the DVMs show no stored voltage anymore, then fix.

morganc · « **Reply #69 on:** 2 May 2012, 01:40 am »

Quote from: Unison845 on 1 May 2012, 01:30 pm

DIY is lots of fun, but playing with high voltage is deadly dangerous!

I think everybody who build amplifier got shock from it at least once. For my part I got it more than once, but the most memorable one happened when building a 250TL (20 years ago) amplifier with voltage about 1000V, the amp is very heavy since it is a stereo, probably over 100lbs so moving around was not easy. I got the amp up side down to debug something, then I turned the amp power off and tried to reach a long nose plier, my arm part close to the elbow touched the 4 pin socket and gave me the hardest electrical shock in my life, my heart beat irregularly, i can feel my hair raised straight, and for six moths period, I did not touch that amp, that's how scary it was. I was lucky because the power amp was OFF, it was only the discharge of the storage cap through my arm that gave the shock, so I dont want to think what would have happen if the amp was ON. I also heard of a story that a guy who tried to build an 845 amp that lost a finger. Luckily, with tremendous caution since then, I have not got any shock from amplifier building. But as always, powering a freshly built power amplifier such as the GM70 with 1400V under the chassis for the first time always make my heart racing!

So, while DIY is fun, I would suggest any starter to proceed building high voltage stuff with lots and lots of precaution, sometimes it might be worth it to pay somebody to build an amp for you rather than taking chances, especially if you own quite a few Apple or Google stock. Starting DIY in other area such as speakers, DAC, turntable are also lots of fun but much less dangerous.

Hahahahaha.....I said "start DIY"

No question I will stay clear of any high voltages, and though I don't own enough stocks at the moment, I am wise enough to appreciate other people's brilliant efforts

karma8181 · « **Reply #70 on:** 3 Feb 2013, 05:30 pm »

I wish I have your talent, but I am not. Would you consider built me a pair? I love your 845s'. Thanks

Unison845 · « **Reply #71 on:** 17 Feb 2013, 06:51 am »

Finally, I have completed a 211 amplifier that sound rival to the 845 tubes.

morganc · « **Reply #72 on:** 17 Feb 2013, 07:35 am »

Nice work

. I guess I can drop by and pick up those old dusty 845's then

?

Unison845 · « **Reply #73 on:** 17 Feb 2013, 04:50 pm »

The 845s are still being used, my system is tri-amped. Never have enough amp to play with!!

Quote from: morganc on 17 Feb 2013, 07:35 am

Nice work . I guess I can drop by and pick up those old dusty 845's then ?

James Romeyn · « **Reply #74 on:** 17 Feb 2013, 05:38 pm »

Warning to anyone who receives offer to visit Unison845's humble abode: I recommend slow, deep breathing Yoga exercise in your car before you walk up to ring the door bell. You need to be emotionally and physically prepared for the experience of being in this audiophile parallel-universe.

Bring a paper bag to breath into if you are prone to hyperventilation!

underdawg · « **Reply #75 on:** 20 Feb 2013, 05:18 pm »

The pictures here are amazing , wish I had the room for that 1st set up,horns horns and bass cabinets wow

Unison845 · « **Reply #76 on:** 21 Feb 2013, 07:32 am »

That picture is an experimental setup using 4 Tact amp with built in xover, it's more than 7 years old photo. I now multi-amp it with all tubes.

Unison845 · « **Reply #77 on:** 30 Apr 2013, 05:16 am »

This is how the 211 amp was built.

J-Pak · « **Reply #78 on:** 3 May 2013, 03:03 pm »

Very nice work unison845. Curious what you feel are the best interstage transformers?

Unison845 · « **Reply #79 on:** 5 May 2013, 07:11 am »

The best of all is the Tango NC20, no question about it, it become so pricey now, I am not sure it is really worth it. I have not tried the new Tango ISO NC20F , some day I will try to buy a pair. Among the one that I have tried are:Tango NC14, Tango NC15, Tamura STU5K, Lundahl, Electra-Print ...

Quote from: J-Pak on 3 May 2013, 03:03 pm

Very nice work unison845. Curious what you feel are the best interstage transformers?