Author Topic: Valve Base (Read 51069 times)

Darren · « **Reply #50 on:** January 16, 2009, 05:28:25 PM »

I wasn't happy with the way this valve cap was going so decided to approach it with a different idea.

A 20mm SS bar was knurled on it's outer edge, I'll explain why in a mo.

Then drilled and bored to a sliding fit on the valve pin

Testing the fit on the valve

Now I need an insulating jacket for this part, this was made from Teflon. I gave myself 5mm insulation thickness all round. This should be ample.

From above

Below

These two parts are a tight fit. I mean the tolerances aren't even close. If these where two metal parts they would have no chance of being pressed together.
However this is Teflon, slippyest substance known to man, so they say. They're not kidding either, it's quite slippy in your hands and a with 50mm bar you can easily loose your grip.
Anyhow, I was planning to use a press to push these together, but it turned out easy enough to do by hand.
Now you can see why the knurling, it's an attempt at giving them some grip to keep them together. It should work.

I need to tap the SS top with a 5mm thread, but I need to order one first. Then I can fit these two parts together.

The electrical wire will thread into a cross drilled hole and be secured by a grub screw from inside the unit. From inside to avoid anything showing and any "live" metal bits.

The whole contraption will be secured to the valve with two 3mm grub screws. A bit hard to explain but I first need to order a 5mm tap before I can continue.

Darren

Divided he ad · « **Reply #51 on:** January 17, 2009, 09:49:06 AM »

Hi Darren...

So I'm trying to get my head around this!

Is the new knurled part instead of the split copper bit? Is the thread that you are putting into it to make it something like the rendering by Roger?

Or are you making it a little like the pic of the original style clip? A wire exiting the top side of the teflon and the stainless bit with the threaded hole and a bolt clamping the wire to it inside the teflon drum so that no one can touch it?

Just a few questions to keep you busy

I've also thought of a clamp idea so If this dosen't work as well as you envision I could post that? Problem is I'm struggling to Crap o Cad the damn thing!!! It'd probably me easier for me to make it!!

Still my idea might not work, and it wouldn't be your idea, so it's probably a good thing I can't draw!!

I'm more than intrigued about the final product

Ralph.

Darren · « **Reply #52 on:** January 17, 2009, 02:42:33 PM »

Hi Ralph,

I think you got it, replace the copper bit earlier.

This pic should help, now ordered the 5mm tap so should progress soon...

bogstandard · « **Reply #53 on:** January 17, 2009, 05:41:40 PM »

Ahah! You now want it to be a fixed cap rather than a removable sprung loaded one.

Talk about moving the goalposts.

Wasted brain cells Bogs.

Divided he ad · « **Reply #54 on:** January 17, 2009, 06:19:50 PM »

Suddenly it all became clear!!!

Good stuff, Just the snail mail post to delay the job.... I get that quite often too!

Keep us posted.

Ralph.

Darren · « **Reply #55 on:** January 17, 2009, 06:26:07 PM »

Saftey was the main criteria, looks second.

Actually the method of fixing is not terribly important, just so long as it stays put.

TBH H&H would still have a fit and suggest it all goes behind bars. But then I'm not selling it so they can......."place own words here".......

The valve gets a bit hot in use, around 200 degC, but that is unlikely to kill you. Keep you nice and toasty though, esp as there are two of them.....

Brass_Machine · « **Reply #56 on:** January 17, 2009, 10:53:20 PM »

I am dying to see this finished!

Eric

Darren · « **Reply #57 on:** January 18, 2009, 06:59:07 AM »

HI Eric,

Thanks for the encouragement.
Though this is only one part of a whole amp and is quite a big project. Not many people build amps of this caliber.

I believe I'm prob the third to do so, one other chap in the states and another in the UK. Though I think we all started before learning of each other.
There may be others now as I've not really been looking since I started this amp three years ago.

I'll have to take some other pictures of what's involved in making these valves work, it all takes up quite some room....

Darren · « **Reply #58 on:** January 18, 2009, 07:05:57 AM »

This is the only commercial avail 833 valve amplifier....

http://www.stereophile.com/tubepoweramps/704wavac/

Sorta explains why I'm building my own, TBH I would anyway even if I could afford this one...which I can't of course....

Darren · « **Reply #59 on:** May 19, 2009, 07:15:36 AM »

Tim asked for a pic of my valve amps,

Well this is only one in working progress, up and running in this pic though....

Rather than start a new thread I've bumped this one.

Tim go to the start of this thread to see some pictures and details....

I'll take some more of other amps for you...

spuddevans · « **Reply #60 on:** May 19, 2009, 12:14:03 PM »

Quote from: Darren on May 19, 2009, 07:15:36 AM

Tim asked for a pic of my valve amps,

Well this is only one in working progress, up and running in this pic though....

Rather than start a new thread I've bumped this one.

Tim go to the start of this thread to see some pictures and details....

I'll take some more of other amps for you...

I've just read all the way through this thread and

I am impressedm, and a little jealous too. What sort of speakers do you have? Diy as well?

I'd love to see your other valve amps too.

Tim

Darren · « **Reply #61 on:** May 19, 2009, 01:54:51 PM »

Tim,

I've just popped into the music room to take some pictures, please excuse the mess and dust

We are renovating and there is dust everywhere, also this room is packed with stuff as we empty other rooms to work. I do wish the garage would come along more quickly so I can move some things over there. But this rain is really holding things back.

Anyway, some very quick and dirty pics with no posing shots at all....honest....

Not all my amps, some are still packed since we moved and some have found new homes.

My phono stage "True Realism" As you can see things are packed in tightly as we want minimum lead lengths between components due to the low signals. We don't want stray stuff getting in and being amplified along with the music. It's a SRPP circuit and was quite hard to get right. It's a lot more complicated than it looks. Those two little circuit boards are the RIAA stages. Technically quite difficult to get right. Valves are ECC83's.

Always a working progress as you can see....

The amp

The power supply

The Power Amps at a whopping 2W per channel, don't be deceived by two measly watts, these can punch some volume out. All depends on the speakers which are usually built to match. All 1920's valves, my own design using a MH41 triode which I believe I was the first to use for HiFi. Power valve is a PX4.
Each box is mono, so two used to make a stereo.
The 833 amps are tagged onto the end of these as a further stage.

The speakers,

My own design using London Ribbons for the high end, Wharfdales with a wizzer for the mids, and Fane pop 50's 12" for the base, and there is a lot of punchy base, too much in fact.

The turntable, one of many, my own design and build of plinth, tonearm mount, stand etc

The 833 amplifier stage has no caps and no resistors, just a power supply, output transformer and wire. Nothing to get in the way and taint the purity of the music.

As you can see, I'm into HiFi and deff a valve man, hate silicon, sounds dreadful IMHO. A quick and dirt post for you, I could write till the cows come home about this stuff but better not eh

There you go that's a taster for you

spuddevans · « **Reply #62 on:** May 19, 2009, 02:57:41 PM »

I am very impressed.

Not so much now, but a few years ago I was pretty keen into HiFi too, I did seriously consider building my own valve amp, although I probably have gone for a kit as I wasnt to sure of my abilities with high voltages.

One thing that is nigh-on impossible to beat with valve amps (apart from the obvious audio benefits) is the absolutely stunning beauty of them. Imagine the scene. Listening to some great music in a dark room, the only illumination coming from the gentle glow from the valves, Ahh, heaven!!

I did mod a few commercial amps (sillicon though), mostly upgrading the caps to Elna's and improving the psu's in them. I also modded a cheapish cd player with the same sort of thing, and also removing the muting transistors and replacing with a relay. I never had any vinyl so all my music is on cd.

Great mono-bloc's, and kudos on the tight wiring on the RIAA pre-amp.

One seriously impressed Tim.

Brass_Machine · « **Reply #63 on:** May 19, 2009, 03:34:35 PM »

Hey Darren,

How about writing a post on setting us audio newbs on the right path of build say a small valve amp?

Eric

Bernd · « **Reply #64 on:** May 19, 2009, 04:40:34 PM »

Very impressive Darren.

I remember hearing (no pun intended) about these types of amps putting out better music than the silicone jobs of today.

Bernd

John Hill · « **Reply #65 on:** May 19, 2009, 05:18:05 PM »

Darren, I believe you went to the same wiring school I did!

One day in class the flight sergeant handed each of us a box of bits and a circuit diagram to build a triode audio amp. It was not long before he was bawling me out for wasting time and soon after that he was holding up my efforts as an example to the class how not to do things! I damn near had to sit in the corner for a hour while the others finished up.

Then we had the tests, of the 24 in the class mine was the only one that worked!

Darren · « **Reply #66 on:** May 19, 2009, 06:10:56 PM »

Quote from: Brass_Machine on May 19, 2009, 03:34:35 PM

Hey Darren,

How about writing a post on setting us audio newbs on the right path of build say a small valve amp?

Eric

I've got an amp that uses two American TV valves, very plentiful and cheap.

Even better is that it is one of the best sounding amps I have ever built and has been copied all over the world.
My mate designed it for my first valve amp build and I was the first to ever build it (my mate knew it would work so didn't bother to build it himself till much later)
Neither of us got any credit, not even a mention. Together we have built some weird and exotic amps over the years and that where often copied.

Eric, let me dig it out sometime and go through the motions. It's a very simple circuit, can be built in a day or so.

Look up 6EM7 valve amplifier and you will find

Darren · « **Reply #67 on:** May 19, 2009, 06:12:47 PM »

Quote from: John Hill on May 19, 2009, 05:18:05 PM

Darren, I believe you went to the same wiring school I did!

One day in class the flight sergeant handed each of us a box of bits and a circuit diagram to build a triode audio amp. It was not long before he was bawling me out for wasting time and soon after that he was holding up my efforts as an example to the class how not to do things! I damn near had to sit in the corner for a hour while the others finished up.

Then we had the tests, of the 24 in the class mine was the only one that worked!

John, valve amp wiring should be like a birds nest, my PX4 amp is way too neat.....

Darren · « **Reply #68 on:** May 19, 2009, 06:17:15 PM »

Quote from: Bernd on May 19, 2009, 04:40:34 PM

Very impressive Darren.

I remember hearing (no pun intended) about these types of amps putting out better music than the silicone jobs of today.

Bernd

There is no comparison between valves and silicon amplifiers.....silicon is harsh and lifeless. There is no way around it no matter how much money or design you throw at it.

When you hear your first ever female vocals on a valve amp you get a very strange feeling and are compelled to look around to see who is there. It's hard to describe, but most people even if they are not into music get quite confused for a while.

That 6EM7 amp I mentioned is famous for it.

Darren · « **Reply #69 on:** May 19, 2009, 06:22:24 PM »

Quote from: spuddevans on May 19, 2009, 02:57:41 PM

One seriously impressed Tim.

Aww shucks, thanks Tim...

Oh I'm gonna have to build one as a project arn't I

I'd really given up, I've built so many and have found one that made me stop.

Most were just built on a piece of wood, only about three or four were ever cased.

Build it, listen for a while, strip half of it down and try another valve.....

Over and over and over and over and over and over and over and over and over and over and over and over and over

I seriously couldn't tell you how many...

Have a look for we4212 valve or tube as they like to call them, might be a picture out there somewhere?

Divided he ad · « **Reply #70 on:** May 19, 2009, 07:22:50 PM »

Ner ner na ner ner.... I've heard Darrens system play.....

(not really head banging tune but it'll do!)
Loud? Your not kiddin!!

And I don't think it was much turned up!

A bit of Jazz type stuff I think (Darren will tell you) True, very clear. I'd like to hear something I know on it so I could compare the two though

I've seen those circuits up close too

they really are quite unbelievably tightly fitted together! Also seen some of the funkiest valves and diodes ever..... Some of them are just huge!!

Very cool..... I still like the idea of one as a light

Ralph.

John Hill · « **Reply #71 on:** May 19, 2009, 07:28:34 PM »

Quote from: Darren on May 19, 2009, 06:12:47 PM

John, valve amp wiring should be like a birds nest, my PX4 amp is way too neat.....

Not according to the flight sergeant! And you have to use wires of the right colours too!

Weston Bye · « **Reply #72 on:** May 19, 2009, 07:37:41 PM »

Quote from: Darren on November 09, 2008, 08:28:25 PM

Darren,

Do the filaments need to run that hot?

Granted, my experience with tubes is about 35 years in the past, but I only remember the cathodes glowing a warm red, even the radar magnetrons, not bright enough to read the newspaper by. I suspect that there is a reason, but it exacpes me.

Weston

Darren · « **Reply #73 on:** May 19, 2009, 07:43:29 PM »

Quote from: Divided he ad on May 19, 2009, 07:22:50 PM

Ner ner na ner ner.... I've heard Darrens system play..... (not really head banging tune but it'll do!)
Loud? Your not kiddin!! And I don't think it was much turned up!

A bit of Jazz type stuff I think (Darren will tell you) True, very clear. I'd like to hear something I know on it so I could compare the two though

I've seen those circuits up close too they really are quite unbelievably tightly fitted together! Also seen some of the funkiest valves and diodes ever..... Some of them are just huge!!

Very cool..... I still like the idea of one as a light

Ralph.

I'll put some Slade on for you next time Ralph, that works well

Darren · « **Reply #74 on:** May 19, 2009, 07:45:45 PM »

Quote from: John Hill on May 19, 2009, 07:28:34 PM

Quote from: Darren on May 19, 2009, 06:12:47 PM

John, valve amp wiring should be like a birds nest, my PX4 amp is way too neat.....

Not according to the flight sergeant! And you have to use wires of the right colours too!

I always thought people in authority were the least experienced or knowledgeabe....that confirms it.....

It's to do with picking up stray inductance/capacitance from nearby wires. Better if they cross sharply.

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Author Topic: Valve Base (Read 51069 times)

bogstandard