Home » Audio » Group Build » 811 project - bases finished
811 project - bases finished [message #31185] Thu, 16 June 2005 23:14 Go to next message
colinhester is currently offline  colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas
Illuminati (3rd Degree)
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

Re: 811 project - bases finished [message #31186 is a reply to message #31185] Fri, 17 June 2005 17:54 Go to previous messageGo to next message
Forty2wo is currently offline  Forty2wo
Messages: 163
Registered: May 2009
Master
Cool, I would love to see the schematic. Got more parts for the DRD should be able to post soon...John

Re: 811 project - bases finished [message #31187 is a reply to message #31186] Fri, 17 June 2005 19:34 Go to previous messageGo to next message
colinhester is currently offline  colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas
Illuminati (3rd Degree)
Wayne asked the editor of VTV, John Kittleston (sp?), for permission to reprint the schematic in this forum, and John agreed. It should be posted as soon as Wayne receives the file.....Colin

Re: 811 project - bases finished [message #31188 is a reply to message #31187] Sat, 18 June 2005 00:19 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18670
Registered: January 2001
Illuminati (33rd Degree)

I'm surprised CK hasn't sent the image file yet. But he did agree, so if one of you has a scanfile, send it over and I'll upload it into the Projects directory.


Re: 811 project - bases finished [message #31189 is a reply to message #31188] Sat, 18 June 2005 14:25 Go to previous messageGo to next message
Brucie is currently offline  Brucie
Messages: 8
Registered: May 2009
Esquire
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 : )

Ding, Ding, Ding - We have a winner!!!!! [message #31190 is a reply to message #31189] Sat, 18 June 2005 16:27 Go to previous messageGo to next message
colinhester is currently offline  colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas
Illuminati (3rd Degree)
Thanks for the link. I looked everywhere for this schematic on the web. I'm just about to do parts selection and ordering. I would love to hear any and all suggestions you have. Can you post pictures of your build? How does it sound?.......Colin

Suggestions [message #31191 is a reply to message #31190] Sat, 18 June 2005 20:15 Go to previous messageGo to next message
Brucie is currently offline  Brucie
Messages: 8
Registered: May 2009
Esquire
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.




Re: Ding, Ding, Ding - We have a winner!!!!! [message #31192 is a reply to message #31190] Sun, 19 June 2005 09:40 Go to previous messageGo to next message
Brucie is currently offline  Brucie
Messages: 8
Registered: May 2009
Esquire
Just had a thought. I believe Eric Barbour occasionally posts on this site. I wonder if he could be persuaded to comment on any additional thoughts he might have or if he would care to second guess himself in any way looking back some years at this design.

Re: Ding, Ding, Ding - We have a winner!!!!! [message #31210 is a reply to message #31192] Fri, 01 July 2005 01:00 Go to previous messageGo to next message
metasonix is currently offline  metasonix
Messages: 103
Registered: May 2009
Viscount
>I believe Eric Barbour occasionally posts on this site.
>I wonder if he could be persuaded to comment on any
>additional thoughts he might have


what?


Re: Ding, Ding, Ding - We have a winner!!!!! [message #31217 is a reply to message #31210] Fri, 01 July 2005 15:37 Go to previous message
Brucie is currently offline  Brucie
Messages: 8
Registered: May 2009
Esquire
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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