Parallel Single Ended Ultralinear KT-88 Amps

the thermionic watercooler

Parallel Single Ended Ultralinear KT-88 Amps

Postby TomMcNally » Sat Nov 12, 2016 1:14 pm

I built these KT-88 mono blocks over the last couple of weeks. Parallel Ultralinear with Edcor XPWR033-120 Power Transformer, Edcor CXSE25-8-2.5K Outputs, Edcor CXC125-10H-200mA Choke and Edcor XC75-2H-200mA Choke. Mirror image chassis. ECC-85 driver. Heavy amps, about 28 pounds each. LED bias on the ECC85. This is a Kegger design, with adjustable feedback.
"KG-KT88 Parallel SEUL"

Image
Image
Image
Image
Image
User avatar
TomMcNally
Darling du Jour
 
Posts: 2729
Joined: Sat Nov 19, 2005 2:19 pm
Location: Northfield, NJ

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby Geek » Sat Nov 12, 2016 6:51 pm

Another sweet build! :))

But there might be an issue if there were some fatter bottles involved? (???)

Cheers!
-= Gregg =-
Fine wine comes in glass bottles, not plastic sacks. Therefore the finer electrons are also found in glass bottles.
User avatar
Geek
KT88
 
Posts: 3585
Joined: Sun Oct 21, 2007 3:01 am
Location: Chilliwack, British Columbia

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby TomMcNally » Sun Nov 13, 2016 3:45 pm

That was a surprise. A nice top plate with new holes would have been the cure. :))
User avatar
TomMcNally
Darling du Jour
 
Posts: 2729
Joined: Sat Nov 19, 2005 2:19 pm
Location: Northfield, NJ

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby kmolles » Thu Nov 24, 2016 8:44 pm

Nice job, Tom!
Kelly Molles
kmolles
 
Posts: 25
Joined: Thu Mar 25, 2004 12:10 am
Location: Napa, CA

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby 20to20 » Tue Nov 29, 2016 10:24 pm

Really like that mirror layout. Were those a custom order and sold?
Headed for Tishomingo to sing in a can...
User avatar
20to20
KT88
 
Posts: 566
Joined: Wed Apr 21, 2010 1:48 pm
Location: W-S, NC

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby skidave » Fri Dec 02, 2016 8:45 am

Nice Work!

Where did you get those small turret boards? I like that idea!

Dave
User avatar
skidave
 
Posts: 141
Joined: Fri Jan 06, 2006 2:04 pm
Location: York, PA

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby brians7 » Fri Dec 02, 2016 8:26 pm

20to20 wrote:Really like that mirror layout. Were those a custom order and sold?


Yes I had Tom build them for me. I have only been listing to them for a couple of days but my first impressions are they sound very nice. I never heard the Kt88 tube before so I don't no if is the tubes are the circuit or a combination of both but they have a polite sweet open sound. I should have had him use the XPWR222 power transformer but was not sure he could get all that iron to fit. This is the third amp he has built for me. Tom always aims to please and I look forward spending lots of time with these amps.
brians7
 
Posts: 37
Joined: Tue Mar 22, 2011 6:35 pm
Location: Beaumont Tx

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby soundbrigade » Sat Dec 03, 2016 8:59 am

ECC85 as drivers!!!??? That was odd, really. What was the main idea behind using that tube?

Some people have very special opinions about the ECC85 (6AQ8/6N3P), meaning they are non-linear etc etc. However I find it in the Luxman MQ-60 (that I plan to build) and I have no objections.

PS. Nice build.
Magnus

"It is always more difficult to fight against faith than against knowledge."
User avatar
soundbrigade
KT88
 
Posts: 1760
Joined: Mon Jan 28, 2008 4:57 am
Location: Little Paris, Sweden

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby 20to20 » Sat Dec 03, 2016 9:57 am

brians7 wrote:
20to20 wrote:Really like that mirror layout. Were those a custom order and sold?


Yes I had Tom build them for me. I have only been listing to them for a couple of days but my first impressions are they sound very nice. I never heard the Kt88 tube before so I don't no if is the tubes are the circuit or a combination of both but they have a polite sweet open sound. I should have had him use the XPWR222 power transformer but was not sure he could get all that iron to fit. This is the third amp he has built for me. Tom always aims to please and I look forward spending lots of time with these amps.


I wondered who built those. I found a very interesting thread over on AK about those amps and couldn't tell who was doing the building,,, seemed like you were in the posts but the photo was unmistakeable. Very famous backdrop...
Headed for Tishomingo to sing in a can...
User avatar
20to20
KT88
 
Posts: 566
Joined: Wed Apr 21, 2010 1:48 pm
Location: W-S, NC

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby brians7 » Sat Dec 03, 2016 1:09 pm

brians7
 
Posts: 37
Joined: Tue Mar 22, 2011 6:35 pm
Location: Beaumont Tx

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby TomMcNally » Sun Dec 04, 2016 3:41 pm

Sorry for the slow response, my home internet has been sluggish for 2 weeks. Ugh

Thanks for all the nice comments, those amps are definitely cool looking.

Giving Brian some credit, he designed the mechanical layout, I modified it for better weight distribution and mirrored them. Brian also picked out and ordered all of the parts. All I did was make holes in the chassis and solder stuff together. lol

The turret strips are on eBay: http://www.ebay.com/itm/1PC-Generic-6-P ... 33820269a2

I've made them before with green board and fork terminals. These are easier. My method to avoid drilling more holes, it to mount a 3/4" to 1" hex space with 4-40 threads on one side of the tube socket mounting. That puts the turret strip up high, and it's easy with a decent amount of room underneath to connect parts to the socket.

... tom
User avatar
TomMcNally
Darling du Jour
 
Posts: 2729
Joined: Sat Nov 19, 2005 2:19 pm
Location: Northfield, NJ

Re: Parallel Single Ended Ultralinear KT-88 Amps

Postby EWBrown » Mon Dec 05, 2016 9:31 am

What is the output power per channel? I'd SWAG that parallel KT88s could generate about 20W RMS, at least.

/ed B in NC
Real Radios Glow in the Dark
User avatar
EWBrown
Insulator & Iron Magnate
 
Posts: 6389
Joined: Wed Mar 19, 2003 6:03 am
Location: Now located in Clay County, NC !


Return to diy hifi

Who is online

Users browsing this forum: No registered users and 8 guests