6C33C spacing

[M Gregg]

Just a quick question,

Does anyone know the minimum distance that should be between 6C33C's? (The idea of one tube distance would make it ridiculous!)


Regards
M. Gregg

[kevinkr]

Originally Posted by M Gregg

Just a quick question,

Does anyone know the minimum distance that should be between 6C33C's? (The idea of one tube distance would make it ridiculous!)


Regards
M. Gregg

That would be about the minimum IMVLE, these tubes run extremely hot.

[M Gregg]

Originally Posted by kevinkr

That would be about the minimum IMVLE, these tubes run extremely hot.

Thank's,

I will work to one tube distance then..a bit more design and thought required!

Regards
M. Gregg

[K.A.B]

Before I built my 6C33C SE, I did a survey on the web, I found some good info most on German sites. What I found was that a minimum is 60mm otherwise the tubes will be overheated I have 70mm between mine.

But I have also a subchassi which tubes are mounted 8-10mm under the top panel then there are larger hole for the tube which diameter is 75-80mm this together creates a chimney effect that also helps to cool the tubes further.

Look at these links and you'll see what I mean.

6C33C-B SE Verstaerker von Juergen Buschmann

6C33C - PP-Amp von Ernst Roessler

Good luck

Anders

[M Gregg]

Originally Posted by K.A.B

Before I built my 6C33C SE, I did a survey on the web, I found some good info most on German sites. What I found was that a minimum is 60mm otherwise the tubes will be overheated I have 70mm between mine.

But I have also a subchassi which tubes are mounted 8-10mm under the top panel then there are larger hole for the tube which diameter is 75-80mm this together creates a chimney effect that also helps to cool the tubes further.

Look at these links and you'll see what I mean.

6C33C-B SE Verstaerker von Juergen Buschmann

6C33C - PP-Amp von Ernst Roessler

Good luck

Anders

Anders,

Thank's for the links, some interesting designs.

Do you have any more useful links for layout Or construction tips regards the heat in these projects? Building OTL.. lol

It would be interesting to see any pics of OTLs anyone has built...or problems they have encountered / overcome.


Regards
M. Gregg

[rvrazvan]

OTL?!?!!??? Good luck man . I'm having a hard time finishing a SE with these tubes ).

[Alain Dupont]

Hi,

Morgan Jones "Building Valve Amplifiers"

In there it discusses how the heat from tubes like the KT88 and similar is mostly thrown out 2 sides, which are the flat sides of the tube anodes. If you have the KT88s less than 4" apart then at least make sure the anode flats are to the side and not in the line running through the tubes.

Good luck with your project.

Alain.

[knoberik]

Originally Posted by M Gregg

It would be interesting to see any pics of OTLs anyone has built...or problems they have encountered / overcome.

Some images of my OTL amp design. Space from 6C33C tube to tube is app. 70 mm. Temperature measured on bulbs hootest spot is +160C deg. Hottest spot is on tube's side, as tubes top stays somewhat cooler.
No problems at all, as there is strong upways rising chimney effect thru the amp's case. Inner temperature stays at around +40C deg. in normal home conditions. Upper plate carrying tubes is 2 mm steel, laser cut. This plate's temperature is around +55C deg. and it participates a bit in cooling of 6C33C tube sockets.

[K.A.B]

A member here at Diyaudio who have built 6C33 OTL is tubetvr he tried to convince me to build an OTL but I had all the things I needed for a SE already. You can contact him he has helped me when I needed help.

Tubeamplifiers

Anders

[M Gregg]

Originally Posted by knoberik

Some images of my OTL amp design. Space from 6C33C tube to tube is app. 70 mm. Temperature measured on bulbs hootest spot is +160C deg. Hottest spot is on tube's side, as tubes top stays somewhat cooler.
No problems at all, as there is strong upways rising chimney effect thru the amp's case. Inner temperature stays at around +40C deg. in normal home conditions. Upper plate carrying tubes is 2 mm steel, laser cut. This plate's temperature is around +55C deg. and it participates a bit in cooling of 6C33C tube sockets.

Thank's For the interesting information,

Also the schematic. That’s an interesting amp you have built.

Does it levitate as well.. LOL

A few questions:

What is the diameter of the unit?

Interesting use of the vellman timer.
What are the readouts showing?
Do you use the counter function as well?

I guess you could program this to have a burn in function?

Are the push buttons are ON /OFF retentive relays / no volt protection?

I see you have also used a current limiting relay.

Could you describe the start sequence?

You have approx 5500F in each rail, I'm looking at 4700uF + addition 1000uF similar to Alastair E.

Did you have any awkward circuit design problems ?

Regards
M. Gregg