Tube Design Sessions?

Scott F. · « **on:** 19 Jan 2005, 02:37 am »

Hiya Guys,

I’ve come up with another hare brained idea for the group that I want to pass by you.

Next months update at ETM, I did a review of the Sony SCD595 SACD player. It’s a dirt cheap 5 disc SACD player available at Best Buy for $150. It sounds way better than it has the right to. If it has one problem it is its output stage. Now it sounds just fine for a piece of solid state gear but it really needs tubes to bring this thing to life (imagine that).

Knowing G is hardcore and isn’t afraid of a challenge, I called him and asked if we could come up with a tubed output stage for this thing. Of course he said ‘sure’.

In the middle of the conversation I had a flash. What if we tapped into our collective knowledge base and rather than our usual listening sessions, we had a few Tube Design classes? Since we’ve got a few guys that are deep into tube design (G, Willie and Thom), what if we could talk them into passing their collective knowledge about tubes and design onto the rest of us? We could have a few gatherings where we all expand our knowledge of tube design and implementation.

I’ve talked to G, Willie and Thom and they are all pretty psyched about teaching us. Obviously, this will be a demand of their free time. Winter is Willies busy time for gigging so we’ll have to schedule the ‘classes’ around their schedules.

If you guys are interested, I’ll try to put together a ‘course schedule’ (I hate referring to this like its class). My thought is to start at the beginning, Ohms Law. Everything we do in design revolves around it. Then we’ll move onto pieces and parts (caps resistors coils), basic circuits (RLC) and progress up the chain. Basically we’ll follow one of the tube designers handbooks (albeit much abbreviated).

My thought is to have everybody build a simple preamp. The reason I picked a preamp is because the overall cost is fairly inexpensive. I don’t think we should use an existing circuit (any that are available on the web). We should pick some cool tube (for me it will be something like an 01, 02, 26 or something) and do the math to come up with a unique preamp design. That way we (are forced to) learn how to do the math and design the circuit. Along the way, we’ll all learn how to read the tube charts in the Radiotron handbook, decipher the ratings and translate those into our own circuits.

Over the years, I’ve downloaded megs upon megs of stuff on tube design. Everything from the early RCA Radiotron (circa 1935 or so) all the way up to the NEETS Manuals (Navy Electricity and Electronics Training Series) to some nifty design programs. I’ll make CD’s of this stuff for everybody along with printing the early Radiotron manual and another tube design guide that has all of the formulas we’ll need so we can use it as a guide.

So what do you guys think?

steve k · « **Reply #1 on:** 19 Jan 2005, 02:53 am »

Excellent idea Scott! As much (or little) as I've read about tube circuitry, I have never been able to put it all together. Even building kits hasn't gotten the basic idea of what is going on in the circuit across to me. Not being mathematically inclined (I'm an architect not an engineer), I need help there too. I'd love to sign up for the course.

I remember having this conversation with Thom at Flip's several years ago and he was excited about it then. Fortunately, we're blessed with the collective genius of yourself, Willie, Thom, G and I know Sturgus knows a thing or two about this stuff to talk the game he does.

Maybe we could enlist the likes of John Hillig for a master class???

Anyway, you got my vote even if for nothing else, I won't look stupid the next time you guys go all techy talky on me!

Sign me up!
steve k

Scott F. · « **Reply #2 on:** 19 Jan 2005, 03:04 am »

Quote from: steve k

...Fortunately, we're blessed with the collective genius of yourself...

You must be mistaking me for somebody else

I know exactly spit about tube designs. I've been trying to wrap my brain around it for a few years now but the signal is still in black and white and really fuzzy. Just like you I'm hoping after some hands on time with guys that understand it, it picture comes through in glorius Technicolor

Quote from: steve k

... Maybe we could enlist the likes of John Hillig for a master class??? ...

Excellent idea! I didn't even thing about John. You wanna get ahold of him and see if he's interested?

steve k · « **Reply #3 on:** 19 Jan 2005, 01:56 pm »

I'll ask John if he's interested. I need to talk to him about my amps anyway.
steve k

DeadFish · « **Reply #4 on:** 19 Jan 2005, 02:54 pm »

Hey Guys,
I would almost be happy with a monochrome 'picture' in my head.
I am gratified to know that I am not the only one that feels their forehead slowly getting flat trying to understand this stuff.
I would most certainly like to be counted in on this 'class'.
Have come to the point where I don't really have a lot of confidence in it *taking*, but I certainly want to try.
Sounds like the fellas that 'know' have their work cut out for them.

Thanks for thinking it up, Scott!

DF

bmed · « **Reply #5 on:** 19 Jan 2005, 03:20 pm »

Wow! That's a great idea. I've always wanted to learn more about design. I like Scott's idea about using a more obscure, cool tube.
My only problem is my location. It would be nice if the "classes" could be held on weekends so I'd have a chance to come, but I understand schedules. It I have to, I guess I could take the "correspondance" version

Cheers,
Brad

electricbear · « **Reply #6 on:** 19 Jan 2005, 03:31 pm »

Great idea, I bet the rest of Audiocircle want to be members of GAS now.
I'd love to get a basic understanding of what is going on in tube designs. Allowing for schedule, count me in.

Brad · « **Reply #7 on:** 19 Jan 2005, 04:21 pm »

That is a terrific idea Scott.
I like the idea of using the obscure tube and having to really learn the math for it to work.

Any room for commuters?

I would also be interested in the correspondence version

Mike D · « **Reply #8 on:** 19 Jan 2005, 08:33 pm »

Great idea. I'm in.

Thank you for this opportunity!!!

Scott F. · « **Reply #9 on:** 19 Jan 2005, 08:54 pm »

Quote from: Brad

That is a terrific idea Scott.
I like the idea of using the obscure tube and having to really learn the math for it to work.

Any room for commuters?
I would also be interested in the correspondence version

Anybody in the area when we have them are welcome to join in.

I'm not sure a typed correspondence version would work. There would be way too much typing involved.

I've thought about documenting what we do on film (digital actually). It could get really boring if I burnt a DVD or CD-V of the sessions. With all I have going on, I doubt I'd ever have time to edit the video. Would be kinda cool if we had somebody act as a cameraman doing the pan tilt zoom thing but I think all our hands and heads will be trying to absorb as much as we can. I'd guess that the camera would be static with a wide shot and general area mic.

Let me think about it a little more. It would be kinda cool to document what we are doing so we could pass the knowledge on to others which is the whole point of what we are doing.

lots to think about in getting ready for this....

Over the next week or so I'll try putting together a schedule and posting it to see what everybody thinks.

steve k · « **Reply #10 on:** 20 Jan 2005, 01:06 am »

Scott,
I'd be happy to record the sessions. I have a digital camcorder and tripod. I would think we'd have some close up work though.
steve k.

pjchappy · « **Reply #11 on:** 20 Jan 2005, 01:18 am »

God, you guys are DORKS!!!

Count me in!

p

JoshK · « **Reply #12 on:** 20 Jan 2005, 02:54 am »

Damn, I wish i could be there... It seems that all the tube DIY'ers are out in LI or upstate, none local.

alexstl · « **Reply #13 on:** 24 Jan 2005, 01:13 am »

I don't know much about tube design but I think the tubes should be glass, cylinder shaped and have the metal electrical stuff on the bottom. I believe I will win for least knowedgeable to start. a humble neophyte, alex

G · « **Reply #14 on:** 26 Jan 2005, 11:00 pm »

Hi guys. The "course won't be the "end all, be all" of tube design but it will enable you to form a solid image in your head of what actually goes on in a tube circuit and why it behaves the way it does. I'm sure things will go "click" in your head at certain points in the "course". I'm fairly sure that I will be able to explain the DC side of things in a reasonably thorough way. I will be big fun!!! Nothing like learning basic electrical theory and drinking Scott's good scotch (heh! heh!). I'm going to leave the logistics to Scotty (The dilythium crystals are shot sir! Aiiii!) but I hope most of you can come. Bring your caliculators

.

G · « **Reply #15 on:** 26 Jan 2005, 11:01 pm »

Quote from: alexstl

I don't know much about tube design but I think the tubes should be glass, cylinder shaped and have the metal electrical stuff on the bottom. I believe I will win for least knowedgeable to start. a humble neophyte, alex

You seem to have a fairly firm grip on the basics.

Tom Grooms · « **Reply #16 on:** 15 Feb 2005, 05:54 am »

I wanna play. I bought the tools and have built the bottlehead foreplay. DIY audio is good with me. Let get the ball rolling.

Scott F. · « **Reply #17 on:** 15 Feb 2005, 08:01 pm »

Hi Guys,

It's been a little while since I posted. Been busy at work. Heres a quick update on the design sessions.

I've been scanning some old literature that I thought everyone could use. I also have been doing some searchs on some information that we all need for the designs (math mainly). I've copied all of that into Word documents so that everybody can print it out. I think I've got all the info everybody should need (I think).

I need to sit down with G and Willie and go over the order and how the information is presented. this is going to be the trickiest part. We don't want to get to deep into theory (and Laws, like Kirchoffs Law) but we still have to visit it so that it still makes sense.

With some luck, the three of us can find some spare time over the next few weeks to sit down and lay out a formal schedule. I'll post more as soon as I can.

Bill Baker · « **Reply #18 on:** 15 Feb 2005, 09:15 pm »

Hey, I wanna play too. I'll bring the calculators. Okay, maybe another time. I'll be thinking about you wjile I am fist deep into another pair of Hurricanes.
So, tubes are made of glass?? I need a refresher course. Have fun and send me a copy of the video feed.

mark@marktwain · « **Reply #19 on:** 16 Feb 2005, 08:18 pm »

Newbie here, This is soooo kewl!

I hope you guys schedule this on a saturday or sunday so I can attend. If not, geeze maybe I'll just have to take a vacation day. Can't wait. Whats a calculator anyway?