6550/KT88 SET amp aka "Uber Beam Machine"

jeffdavison · « **Reply #220 on:** 15 May 2008, 08:24 pm »

time to bump this thread up to the top...
Progress people? or has the Spring and Summer put this on the old "back burner?

JD

nodiak · « **Reply #221 on:** 16 May 2008, 08:18 pm »

Hey Jeff, i'm building the SimpleSE and have the resistors and misc. hardware to order, and will as soon as make a couple decisions (kiwame this, riken that

). Have the transformers, choke, tubes, caps, etc.
Decided on a lay out and got the aluminum top plate cut to dimensions yesterday, and have picked out the wood (burled curly Pacific maple, probably Claro walnut feet).
Mine will be an integrated so I do need to learn what selector to choose for 3 position. Found Audio Tropic a good read about what Poinz uses in his Musical Machine.
Would like to get/make the time in next week or two to drill top plate and build wood chassis while waiting on rest of parts. Not really enjoying doing it a poke at a time, but there it is.
Yes, am hoping to get to it before summer adventures start.
Don

JoshK · « **Reply #222 on:** 16 May 2008, 09:32 pm »

In-laws came to visit, helped my wife and I get some progress done on a couple of large renovation projects, the upstairs bathroom and the basement floor. All else was put on hold.

A whole was done on these big projects, but momentum needs to be kept to finish them out. Until that time, progress on my amp will be here and there.

Where I left off....
1) Aluminum top plate is 98% drilled...need to double check if all part fasteners holes were accounted for.
2) 80% done experimenting with patinas for the copper overlayment (tried a few recipes, and acquired "liver of sulphur" to try)
3) Wood picked and cut to size, dovetail jig guide acquired for router, need to dovetail pieces and assemble and finish.
4) All parts acquired
5) Building Valve Amplifiers (Morgan Jones) half read, the half about building amps.

jrebman · « **Reply #223 on:** 16 May 2008, 10:04 pm »

I'm in a holding pattern recovering from foot surgery and am not very mobile these days, and still not sure when things will be back to "normal".

I've also had a change of heart about the SimpleSE project. Not that I think it a bad or overly compromised design, but rather because I feel as if I'm nearing the point where I will feel confident enough to tackle my own design and want to do a 3 chassis monoblock SE 6550 amp(s) as opposed to a single chassis model.

Other than Iron and some resistors and such, I really don't have very much invested in the SimpleSE (other than the PCB), so using the iron in a new design is no big deal, and even better as I can now measure the characteristics of the transformers and optimize the rest of the circuit to take best advantage of them.

Alas, I have to spend most of my time in bed with my foot elevated, so it's all just talk at this point.

-- Jim

jeffdavison · « **Reply #224 on:** 16 May 2008, 10:27 pm »

Got my front and rear control panels and top plate done. Gluing up the rosewood base this weekend. All sub assembly PCBs done, still need testing to verify against the PSUDII numbers. I've decided to go 6vac for all the filaments and nixed the 12SX7GT for a 6SN7GT. So i won't be using up precious space with a seperate 12dc traffo, rectifeier and regulator. Got all NOS tubes here... going with a couple of 5V4G's for rectifiers..actually Mullard GZ32's. So the topology goes..6SN7 input to a 100K stepped attenuator into a 6H30p-DR driver to a pair of Tun-Sol 6550 black plates. All iron on hand now. Got some aluminum boxes from Zero Case to pot and top mount a couple of chokes and for the Toroid, all painted nicely with a bronze hammertone..

Guys.... I always like to think ahead a few steps and now thinking about speakers....I know, another forum, but this will be one of my systems, hopefully synergystic on the "simple" theme, so I'll be doing a single full range on an open baffle. Man what a zoo out there! Price ranges from cheap to megabuck. Norway Seas Exotic, Japanese Feastrex, French Supravox, Canadian Hemp, let alone the vintage Altec's, the stalwart Fostex's, the Visitons...etc.. etc....etc... Waht are you all planning to do?

Got a very late start on the amp project, but seem to have gotten fairly caught up to you guys., should have some more pics next week.

JD

JoshK · « **Reply #225 on:** 16 May 2008, 11:32 pm »

Quote from: jeffdavison on 16 May 2008, 10:27 pm

Got some aluminum boxes from Zero Case to pot and top mount a couple of chokes and for the Toroid, all painted nicely with a bronze hammertone..

I am not familiar, do you mind sharing a link?

jeffdavison · « **Reply #226 on:** 17 May 2008, 12:59 am »

http://www.zerocases.com/catalog/deep-drawn-enclosures.html

JoshK · « **Reply #227 on:** 17 May 2008, 01:47 am »

Excellent, thanks! I like what I see. Funny how this didn't turn up in a google search.

jeffdavison · « **Reply #228 on:** 26 May 2008, 04:44 am »

Base finished and all parts asssembled on base. Just have to wire it up this week and start the testing.

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1461

JD

nodiak · « **Reply #229 on:** 26 May 2008, 05:57 pm »

Looks really great Jeff. Anxious to hear your results.
Don

DaveC113 · « **Reply #230 on:** 26 May 2008, 06:18 pm »

Jeff, beautiful amp!

I hope to have my SimpleSE finished in a couple weeks, and will probably test it in a week or so. It's a straight power amp with no pot and will use a JJ ecc99 driver tube w/CCS instead of the 12at7 and Tung Sol 6550 power tubes. The top panel is out at the machine shop (thanks Mike!) having some of the bigger holes machined on a mill. The chassis will be maple burl lumber with figured walnut corners and brass feet. Even using modest parts like James OPTs and the Allied PT its approaching $700 in parts. I did go for higher end resistors, Mundorf SIO caps, and Vampire RCA inputs and binding posts, and motor run caps and a choke in the ps, but I don't think you could get by with much less than $400. As long as I like it a lot more than my modified Trends T-amp I'll be happy.

jeffdavison · « **Reply #231 on:** 28 May 2008, 12:52 am »

Inside chassis shot... not yet wired..
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1461&pos=16

JD

nodiak · « **Reply #232 on:** 28 May 2008, 01:59 am »

Hey Jeff, inspiring man! Keep the photos coming, especially underneath after wired.

JoshK · « **Reply #233 on:** 28 May 2008, 01:40 pm »

Excellent work Jeff!

Its pretty clear you are going all out. What did you use for the mess screen in the bottom cover? That is something I'd like to acquire but the stuff from online metals is a bit more than I wanted to spend on such a thing.

GBB · « **Reply #234 on:** 28 May 2008, 01:48 pm »

Quote from: JoshK on 28 May 2008, 01:40 pm

What did you use for the mess screen in the bottom cover? That is something I'd like to acquire but the stuff from online metals is a bit more than I wanted to spend on such a thing.

Josh,
I'm not Jeff, but I can tell you where I get my perforated metal. I buy it from Small Parts.
http://www.smallparts.com/products/descriptions/pma.cfm

For perforated aluminum, their prices seem to be pretty reasonable.

---Gary

JoshK · « **Reply #235 on:** 28 May 2008, 02:35 pm »

Thanks Gary!

jeffdavison · « **Reply #236 on:** 28 May 2008, 04:14 pm »

http://HTTP://WWW.MCMASTER.COM

here's the webpage frame:

http://www.mcmaster.com/param/asp/PSearch2.asp?reqTyp=parametric&act=psearch&FAM=wirecloth&FT_2894=125695&FT_2837=123500&FT_2839=123469&FT_138=89664&FT_128=130593&session=wirecloth,2894=125695,2837=123500,2839=123469,138=89664;128=130593&sesnextrep=580871521030968&ScreenWidth=1280&McMMainWidth=1073

Quote from: JoshK on 28 May 2008, 01:40 pm

xcellent work Jeff! Its pretty clear you are going all out. What did you use for the mess screen in the bottom cover? That is something I'd like to acquire but the stuff from online metals is a bit more than I wanted to spend on such a thing.

jeffdavison · « **Reply #237 on:** 30 May 2008, 04:38 pm »

Just for your information for those who refference TubeLab...

Their (George's) web site is down for the time being...

http://www.diyaudio.com/forums/showthread.php?s=&threadid=123941

jrebman · « **Reply #238 on:** 30 May 2008, 04:51 pm »

I just tried the site and it appears to be working right now. George is going to migrate to a different hosting service as soon as he can, so availability may be spotty until that is complete.

In other news, if anybody knows a friend who is considering building a Simple SE, I can make them a very good deal on a nearly complete kit of parts, including a full complement of custom Electraprint iron. I'm not advertising this anywhere else for the moment, but probabluy will once things settle down a bit here.

Don't ask -- way too complicated to explain.

-- Jim

Grumpy_Git · « **Reply #239 on:** 31 May 2008, 09:46 am »

Jim

I was looking at a simple se but I'm in the uk. that probably keeps me out, if not let me know by pm. i'm very interested.

Nick.