811 project - bases finished [message #31185] |
Thu, 16 June 2005 23:14 |
colinhester
Messages: 1349 Registered: May 2009 Location: NE Arkansas
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Illuminati (3rd Degree) |
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Well, Got the power Tx's in yesterday (big thanks to Forty2wo) and started building the bases for the monoblocks. The wood bases are cut and glued, and the copper tops (12 x 18") are cut to fit. Should be ordering the rest of the iron and parts this week or early next.....Colin
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Re: 811 project - bases finished [message #31189 is a reply to message #31188] |
Sat, 18 June 2005 14:25 |
Brucie
Messages: 8 Registered: May 2009
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Esquire |
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Try the following page:www.bonavolta.ch/hobby/en/audio/sv811_2.htm I built mine as a stereo amp with outboard power supply and a 6DN7 input/driver, which I liked a little better. Most recently added inexpensive grid chokes. Sweet amp. I was hoping you would change your mind as I am looking for cheap spares for the output and didn't want you to popularize it : )
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Suggestions [message #31191 is a reply to message #31190] |
Sat, 18 June 2005 20:15 |
Brucie
Messages: 8 Registered: May 2009
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Esquire |
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I like the amp a lot. I'd suggest you not skimp on OPT or power supply. I've made a fair amount of revisions and mods, including stereo chassis and SS rectifier. I don't know that made a positive difference, I'm just more comfortable with that style build. I think the three biggest improvements (to my ear) are: 1: Filament snubbers for all tubes (no hum for all practical purpose thru 97 db speakers 2: 6DN7 input driver. Plate resister 90K and cathode resister something like 1.23K. IIRC plate voltage approx 150 volts and 4.5 volts at cathode. CF about 150 volts to ground. 3: Inexpensive grid chokes. This is the most "off the wall" experimental change. Thats what makes me happiest that it worked and worked well. Two of the $11, 150H 8ma filter chokes in series per channel. Isolate from chassis. Ground body to chassis through a .47uf poly cap. Give it 50+ hours to break in. I ran it in parallel with the grid resister.I would certainly recommend you build per schematic first and then play around. Oh yeah, have lots of fun with it.
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Re: Ding, Ding, Ding - We have a winner!!!!! [message #31217 is a reply to message #31210] |
Fri, 01 July 2005 15:37 |
Brucie
Messages: 8 Registered: May 2009
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Esquire |
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Hi Eric. Sorry if I wasn't clear. I had just posted that I had built your amp (which I liked very much) but with a few minor changes from your schematic. I was just wondering if, with the benefit of hindsight and several years of living and learning, you might do anything differently. (Grid chokes, different driver, CCS, yadda yadda? In other words, any additional advice re building your amp from that of a few years ago?
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