Another fun build. Driver and phase splitter. - UK Vintage Radio Repair and Restoration Discussion Forum

Tubeglow · 1st Apr 2014, 2:44 pm

Just for interest,

Tubeglow.

ValvoStef · 1st Apr 2014, 2:54 pm

Slow down buddy, you build more amps than cans of beer I have in the fridge.
Looks absolute fab, even with nothing in it.

Tubeglow · 1st Apr 2014, 3:54 pm

It was built a couple of years ago.

Another moment of madness (technics circuit) but it has passed.

Well sort of.

I thought the build might be interesting. Its still running strong..

Tubeglow.

1st Apr 2014, 5:07 pm

You are worse than me, I love making things too, in wood, bricks, metal, electronics, software, firmware, well anything really. Everyone should (must?) have a workshop even if it's the classic kitchen table.

This must be added to the school curriculum as a core subject.

Tubeglow · 1st Apr 2014, 5:10 pm

Driver and phase splitter.

Components are:
Resistors Kiwame/Takman MF/Tantalum.
Capacitors Jupiter/Amtranz- modified to Robert Hovland super cap. Wima.

PSU build.

Tubeglow.

ValvoStef · 1st Apr 2014, 5:10 pm

These are things you cannot buy in a shop, you have to build it yourself. Creativity has no limits, the equiment is repairable unlike the modern junk, and it is something you can be proud of and make others jealous.

May I ask where you get the toroidals from, please?

Tubeglow · 1st Apr 2014, 5:19 pm

No special place.
I just look around, the biggest problem is getting the noise down on Toroids.
These came from Airlink however their range has reduced recently.

The Neon's on the board are for DC coupling protection for the grid and to protect the cathode against over voltage on start up.

Quote:

Originally Posted by merlinmaxwell

You are worse than me, I love making things too, in wood, bricks, metal, electronics, software, firmware, well anything really. Everyone should (must?) have a workshop even if it's the classic kitchen table.

I hope posting will inspire others to build..

This was a labour of love..LOL

Tubeglow.

ValvoStef · 1st Apr 2014, 5:30 pm

I have to say, your builds are very neat and compact and everything looks so professional.

Tubeglow · 1st Apr 2014, 5:33 pm

The trick is to plan.

Look at the circuit then place the parts on a piece of cardboard and cut it to the size so you get a template before you build anything.

This is the top plate build. These valves run VERY hot!
So the cooling has to be planed carefully.

Resistors are Mills and Kiwame with PTFE cable and solder selected for application (Eutectic) and high temperature.
This amp uses High current drive and the PSU can deliver high current at 400V B+.
Bias is Mixed with auto cathode bias and fixed bias set point to allow for valve wear. (It also sounds better, just my thoughts)
I'll post some more later..just for interest.

Tubeglow.

ValvoStef · 1st Apr 2014, 5:41 pm

This looks like 6C33C push pull? I have been planning ( for many years ) a SE version with those valves. I like the way you split the ams into several modules rather than putting everything on one chassis.

Tubeglow · 1st Apr 2014, 5:44 pm

Valvee is 6C33C more to come.

Tubeglow.

ValvoStef · 1st Apr 2014, 5:49 pm

Looking forward to

Tubeglow · 1st Apr 2014, 6:21 pm

Initial burn in of 6c33c.

The burn in of these valves is critical (Both heaters and no B+ for 12 Hrs Minimum).
Then step up the B+ in stages.
The valve expands over this time and the electrodes settle into position.
The amp has switchable heaters so it can run on half of the valve on lower power.
This reduces the heat and running cost.

The valves are very hot think almost cooker element when mounting them.
The air is driven around the chassis by mounting warm components in strategic positions and using convection.
The valves are in OTL circuit configuration.
The final picture is a test run with Alpair 7 DIY speakers.

And sounds like this:
http://www.youtube.com/watch?v=EbeSIF3FsQE

The switch is to power up the other half of the valve to show audio is acceptable with one triode running.
This was just an initial test run. The valves had not run in at this point.
There is no other bass speaker only what you see in the video.

Here is some electronic bass to show the removal of the output Transformer and effect of the OTL on the sound.
http://www.youtube.com/watch?v=TU2YCTps69U

Anyway I hope it inspires someone..

Tubeglow.

ValvoStef · 1st Apr 2014, 6:45 pm

Thanks for the info, Tubeglow, I'll bear this in mind ...

Tubeglow · 1st Apr 2014, 6:59 pm

If you don't do this the valves will flash over in about a week.
The valves had not run in at this point and the Kiwame resistors had not changed to 2nd harmonic.

One more for fun

http://www.youtube.com/watch?v=0B_JTYYLdN4

The thing to remember with this valve is the power consumption..and the supply is high voltage with high current so take great care!

Good luck
Tubeglow.

G8HQP Dave · 1st Apr 2014, 8:37 pm

You have shown lots of pictures and name-dropped boutique components, but where is the circuit diagram? That is what really matters. This is not an audiophile site.

Tubeglow · 1st Apr 2014, 8:49 pm

I've obviously offended you.
I apologise you are correct, this is not an audiophile site.
Mentioning components I have used was just for interest and not meant to offend anyone.

So I withdraw.

Tubeglow.

G8HQP Dave · 1st Apr 2014, 10:14 pm

Not offended. Amused.

valveaudio · 1st Apr 2014, 10:38 pm

For toroids try Tiger Toroids at http://www.tigertoroids.co.uk

Trevor

Tubeglow · 1st Apr 2014, 11:04 pm

Thank's for the link. I have never seen them before.

Tubeglow.

1st Apr 2014, 2:44 pm	#1
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Another fun build. Driver and phase splitter. Just for interest, Tubeglow. Attached Thumbnails Last edited by Tubeglow; 1st Apr 2014 at 2:54 pm.

1st Apr 2014, 2:54 pm	#2
ValvoStef Hexode Join Date: Mar 2014 Location: Fareham, Hampshire, UK. Posts: 482	Re: Another fun build Slow down buddy, you build more amps than cans of beer I have in the fridge. Looks absolute fab, even with nothing in it. __________________ Failing to prepare is preparing to fail ...

1st Apr 2014, 3:54 pm	#3
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build It was built a couple of years ago. Another moment of madness (technics circuit) but it has passed. Well sort of. I thought the build might be interesting. Its still running strong.. Tubeglow.

1st Apr 2014, 5:07 pm	#4
Guest Guest Posts: n/a	Re: Another fun build You are worse than me, I love making things too, in wood, bricks, metal, electronics, software, firmware, well anything really. Everyone should (must?) have a workshop even if it's the classic kitchen table. This must be added to the school curriculum as a core subject.

1st Apr 2014, 5:10 pm	#5
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build Driver and phase splitter. Components are: Resistors Kiwame/Takman MF/Tantalum. Capacitors Jupiter/Amtranz- modified to Robert Hovland super cap. Wima. PSU build. Tubeglow. Attached Thumbnails

1st Apr 2014, 5:10 pm	#6
ValvoStef Hexode Join Date: Mar 2014 Location: Fareham, Hampshire, UK. Posts: 482	Re: Another fun build These are things you cannot buy in a shop, you have to build it yourself. Creativity has no limits, the equiment is repairable unlike the modern junk, and it is something you can be proud of and make others jealous. May I ask where you get the toroidals from, please? __________________ Failing to prepare is preparing to fail ...

1st Apr 2014, 5:30 pm	#8
ValvoStef Hexode Join Date: Mar 2014 Location: Fareham, Hampshire, UK. Posts: 482	Re: Another fun build I have to say, your builds are very neat and compact and everything looks so professional. __________________ Failing to prepare is preparing to fail ...

1st Apr 2014, 5:33 pm	#9
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build The trick is to plan. Look at the circuit then place the parts on a piece of cardboard and cut it to the size so you get a template before you build anything. This is the top plate build. These valves run VERY hot! So the cooling has to be planed carefully. Resistors are Mills and Kiwame with PTFE cable and solder selected for application (Eutectic) and high temperature. This amp uses High current drive and the PSU can deliver high current at 400V B+. Bias is Mixed with auto cathode bias and fixed bias set point to allow for valve wear. (It also sounds better, just my thoughts) I'll post some more later..just for interest. Tubeglow. Attached Thumbnails Last edited by Tubeglow; 1st Apr 2014 at 5:42 pm.

1st Apr 2014, 5:41 pm	#10
ValvoStef Hexode Join Date: Mar 2014 Location: Fareham, Hampshire, UK. Posts: 482	Re: Another fun build This looks like 6C33C push pull? I have been planning ( for many years ) a SE version with those valves. I like the way you split the ams into several modules rather than putting everything on one chassis. __________________ Failing to prepare is preparing to fail ...

1st Apr 2014, 5:44 pm	#11
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build Valvee is 6C33C more to come. Tubeglow.

1st Apr 2014, 5:49 pm	#12
ValvoStef Hexode Join Date: Mar 2014 Location: Fareham, Hampshire, UK. Posts: 482	Re: Another fun build Looking forward to __________________ Failing to prepare is preparing to fail ...

1st Apr 2014, 6:21 pm	#13
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build Initial burn in of 6c33c. The burn in of these valves is critical (Both heaters and no B+ for 12 Hrs Minimum). Then step up the B+ in stages. The valve expands over this time and the electrodes settle into position. The amp has switchable heaters so it can run on half of the valve on lower power. This reduces the heat and running cost. The valves are very hot think almost cooker element when mounting them. The air is driven around the chassis by mounting warm components in strategic positions and using convection. The valves are in OTL circuit configuration. The final picture is a test run with Alpair 7 DIY speakers. And sounds like this: http://www.youtube.com/watch?v=EbeSIF3FsQE The switch is to power up the other half of the valve to show audio is acceptable with one triode running. This was just an initial test run. The valves had not run in at this point. There is no other bass speaker only what you see in the video. Here is some electronic bass to show the removal of the output Transformer and effect of the OTL on the sound. http://www.youtube.com/watch?v=TU2YCTps69U Anyway I hope it inspires someone.. Tubeglow. Attached Thumbnails Last edited by Tubeglow; 1st Apr 2014 at 6:48 pm.

1st Apr 2014, 6:45 pm	#14
ValvoStef Hexode Join Date: Mar 2014 Location: Fareham, Hampshire, UK. Posts: 482	Re: Another fun build Thanks for the info, Tubeglow, I'll bear this in mind ... __________________ Failing to prepare is preparing to fail ...

1st Apr 2014, 6:59 pm	#15
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build If you don't do this the valves will flash over in about a week. The valves had not run in at this point and the Kiwame resistors had not changed to 2nd harmonic. One more for fun http://www.youtube.com/watch?v=0B_JTYYLdN4 The thing to remember with this valve is the power consumption..and the supply is high voltage with high current so take great care! Good luck Tubeglow. Last edited by Tubeglow; 1st Apr 2014 at 7:17 pm.

1st Apr 2014, 8:37 pm	#16
G8HQP Dave Rest in Peace Join Date: Sep 2008 Location: Solihull, West Midlands, UK. Posts: 4,872	Re: Another fun build. Driver and phase splitter. You have shown lots of pictures and name-dropped boutique components, but where is the circuit diagram? That is what really matters. This is not an audiophile site.

1st Apr 2014, 8:49 pm	#17
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build. Driver and phase splitter. I've obviously offended you. I apologise you are correct, this is not an audiophile site. Mentioning components I have used was just for interest and not meant to offend anyone. So I withdraw. Tubeglow.

1st Apr 2014, 10:14 pm	#18
G8HQP Dave Rest in Peace Join Date: Sep 2008 Location: Solihull, West Midlands, UK. Posts: 4,872	Re: Another fun build. Driver and phase splitter. Not offended. Amused.

1st Apr 2014, 10:38 pm	#19
valveaudio Hexode Join Date: Feb 2006 Location: Diss, Norfolk, UK. Posts: 386	Re: Another fun build. Driver and phase splitter. For toroids try Tiger Toroids at http://www.tigertoroids.co.uk Trevor

1st Apr 2014, 11:04 pm	#20
Tubeglow Retired Dormant Member Join Date: Mar 2014 Location: Wolverhampton, West Midlands, UK. Posts: 153	Re: Another fun build. Driver and phase splitter. Thank's for the link. I have never seen them before. Tubeglow.