Hi
Nick again the board is now complete ready for the 1st fire up. Just need to make a bracket for the speaker terminals etc.
This a 1st attempt at a gerber file conversion from artwork, the PCB is 2 oz copper tracks ... nearly complete, then onto a full stereo version (monoblocks) then a kt88 class a version.
this has been a long project .... anyone else interested?
enjoy the pics
Nick again the board is now complete ready for the 1st fire up. Just need to make a bracket for the speaker terminals etc.
This a 1st attempt at a gerber file conversion from artwork, the PCB is 2 oz copper tracks ... nearly complete, then onto a full stereo version (monoblocks) then a kt88 class a version.
this has been a long project .... anyone else interested?
enjoy the pics
Attachments
Very nice work, indeed!
The original output transformers can be found at Plitron homepage:Toroidal Audio Transformers
Some interesting reading on the K4040: Under the skirts on a Velleman 4040 - AudioKarma.org Home Audio Stereo Discussion Forums
The original output transformers can be found at Plitron homepage:Toroidal Audio Transformers
Some interesting reading on the K4040: Under the skirts on a Velleman 4040 - AudioKarma.org Home Audio Stereo Discussion Forums
Hi
Thanks for showing a interest in my work .. I thought for a while no one was interested.
I never knew that they where the original makers of the transformers .. and still available, what product code do you think are from their web site?
many thanks
Nick
Thanks for showing a interest in my work .. I thought for a while no one was interested.
I never knew that they where the original makers of the transformers .. and still available, what product code do you think are from their web site?
many thanks
Nick
Hi!
Yes, quite a feat you pulled there - making a copy of the Velleman PCB, very impressive.
Plitron, I think, have a similar board:
PCB for Tube Amplifiers
And using the transformers PAT4004 or PAT4006.
Some of the information, on what transformer that was in the original Velleman kit, I do have somwhere in this computer, now then, just how to find it 🙂
Some information on the Plitron board: http://www.pearl-hifi.com/06_Lit_Archive/14_Books_Tech_Papers/Van_der_Veen_Menno/Concertina_EL34_PP_Amp.pdf
Yes, quite a feat you pulled there - making a copy of the Velleman PCB, very impressive.
Plitron, I think, have a similar board:
PCB for Tube Amplifiers
And using the transformers PAT4004 or PAT4006.
Some of the information, on what transformer that was in the original Velleman kit, I do have somwhere in this computer, now then, just how to find it 🙂
Some information on the Plitron board: http://www.pearl-hifi.com/06_Lit_Archive/14_Books_Tech_Papers/Van_der_Veen_Menno/Concertina_EL34_PP_Amp.pdf
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Hi
Could when you get time let me have the details of the output transformers as sowter transformers are very expensive.
regards
Nick
Could when you get time let me have the details of the output transformers as sowter transformers are very expensive.
regards
Nick
nick,
as i told you i have modified my 8011,
I have replaced the chinise original output transformer by the LUNDHAL
1623 P-P well known. Result is good and it is a plug in replacement.
Cost was around 400 euros for a pair but today i do not know if it is the same
you could see the cost on DIYparadiso a belgian DIY site.
as i told you i have modified my 8011,
I have replaced the chinise original output transformer by the LUNDHAL
1623 P-P well known. Result is good and it is a plug in replacement.
Cost was around 400 euros for a pair but today i do not know if it is the same
you could see the cost on DIYparadiso a belgian DIY site.
Hi
Yes I remember now and I have seen that site, the LUNDHAL transformers are still available as I have just checked .. have you a connection diagram on how you connected to the PCB? all the best Nick ... how are your repairs going? do you have all the bits that you need now ? nick
Yes I remember now and I have seen that site, the LUNDHAL transformers are still available as I have just checked .. have you a connection diagram on how you connected to the PCB? all the best Nick ... how are your repairs going? do you have all the bits that you need now ? nick
the lundals LL1623 need some customisation to your exact need.
Your have to select on the lundhal site the amplifier configuration triode or ultralinear or pentode... this gives you the wiring to do on the transformer
For myself it is the C' wiring.
As it is a triode configuration you will have 3 wires in and 2 wires out.
It is not difficult but needs some attention.
Your have to select on the lundhal site the amplifier configuration triode or ultralinear or pentode... this gives you the wiring to do on the transformer
For myself it is the C' wiring.
As it is a triode configuration you will have 3 wires in and 2 wires out.
It is not difficult but needs some attention.
hello
Yes I was going to try today (Sunday) I fired it up yesterday and all seemed to be ok, all the EL34's biased correctly and no hum from the speaker
regards
Nick
Yes I was going to try today (Sunday) I fired it up yesterday and all seemed to be ok, all the EL34's biased correctly and no hum from the speaker
regards
Nick
Hi Please find some attached pics of the K8011 being fired up for the 1st time.
The only fault I found was that one of the bias leds was the wrong polarity, apart from that all seems ok
will check today with music .. the only true test
The only fault I found was that one of the bias leds was the wrong polarity, apart from that all seems ok
will check today with music .. the only true test
Attachments
Hi
well end of a journey, it all works and sound great, treble clear and bass well controlled
Just need to put in a case and make the other channel .. then on to a KT88 version, currently using sovtek valves .. sound ok to me
regards Nick
well end of a journey, it all works and sound great, treble clear and bass well controlled
Just need to put in a case and make the other channel .. then on to a KT88 version, currently using sovtek valves .. sound ok to me
regards Nick
Attachments
Hi
Nick again .. just to note that the main benefit from the newer PCB (apart from the fact that I now have a full set of Gerber files)
is that the board uses 2 oz copper tracks, this allows diyers to remove parts and not so experienced people with regarding soldering skills .. not to worry to much about the tracks lifting away from the board.
I will upload some more pictures when the are fully enclosed
regards
Nick
Nick again .. just to note that the main benefit from the newer PCB (apart from the fact that I now have a full set of Gerber files)
is that the board uses 2 oz copper tracks, this allows diyers to remove parts and not so experienced people with regarding soldering skills .. not to worry to much about the tracks lifting away from the board.
I will upload some more pictures when the are fully enclosed
regards
Nick
nick,
you are right about tracks lifting in the original board
i have experienced that myself as i have improved the circuit and that mean soldering and desoldering the same components a few times.
But in the same time for people who deal with the k8011 for the first time the original has the benefit of being engraved with the components positions
you are right about tracks lifting in the original board
i have experienced that myself as i have improved the circuit and that mean soldering and desoldering the same components a few times.
But in the same time for people who deal with the k8011 for the first time the original has the benefit of being engraved with the components positions
Hi
I have 2 K8011/10 new original PCB's left for £100 the pair plus postage .. once they have gone they have gone. Postage in the UK should be no more then £10
let me know if interested before I put on Ebay ?
happy new year
these boards are brand new never been used
I have 2 K8011/10 new original PCB's left for £100 the pair plus postage .. once they have gone they have gone. Postage in the UK should be no more then £10
let me know if interested before I put on Ebay ?
happy new year
these boards are brand new never been used
hi nick
happy new year
yes i need one PCB and some critical parts as you sold me the first time
the first time i paid 50 pounds for the pcb around 40 pounds for parts and 17 pounds for transport to Paris france
Can we deal on this basis?
happy new year
yes i need one PCB and some critical parts as you sold me the first time
the first time i paid 50 pounds for the pcb around 40 pounds for parts and 17 pounds for transport to Paris france
Can we deal on this basis?