• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

K8011/K8010 PCB build thread

Bespoke Constructor
Joined 2006
Paid Member
Hi

I have always been a fan of these mono block amplifiers via velleman .. both the el34 and kt88 version.
Velleman have long since stopped production of these years ago .. I purchased their last 27 boards they had in stock. I have now since decided to make my own new production boards (Velleman where ok) but the issue was that these boards where made before Gerber files.

So after some hard work I produced the artwork the old fashion way then painstakingly converted to a full Gerber file so I can get them made again.

My new boards are fully drilled with 2oz copper tracks. This is the 1st production board being populated, with the wire links 1st .. I will update more on the progress of the first board. This will be A 90w EL34 version. The new PCB boards are thicker as well so no flex ..
 

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Bespoke Constructor
Joined 2006
Paid Member
Hi

Some more pics

These show the chassis in preparation and the power / output transformers being bolted to the chassis

Then the PCB being offered up for alignment purposes ... This will be the first prototype replica of the K8011/k8010 mono block valve amplifier based on EL34 valves
 

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Bespoke Constructor
Joined 2006
Paid Member
Hi

Some more progress on the k8011 PCB (90w RMS Mono block)
This is a new PCB with my own Gerber files with 2 oz copper tracks ..
 

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hello nick,
i have built the K 8011 with EL34 and still have them. but one of the monos has a failure and i have not been able and lucky in findind the component out of sevice.
I am interested in a board to allow me to rebuild it from scratch (today one mono is ok and the second is out of service)
What would be the cost of a board (your new one or the genuine velleman if you have one)
For your info my K 8011 have been deeply improved with the help of a belgian professional mister benny of DIYPARADISO.
The biasing of the two ECC82 and ECC83 have been modified,the interstage capacitors are JENSEN cooper in oil, a choke has been added in the HV power suply and the output transformer is a LUNDHAL one
Last are the the components for the EL34 biasing (it is an integrated circuit)and the protection part easy to found?
regards
 
Bespoke Constructor
Joined 2006
Paid Member
Hi

Nick Again .. I have had a few requests if I could offer a full kit for k8010 & k8011 mono block amplifiers.

I have been thinking about a small business venture but the transformers would make the kits very expensive, or I could offer a small form factor kit without valves and the transformers

what do you all think ??

regards

Nick
 
Hi,
I'd think a full kit would mean less experienced builders and more questions.

Partial kit (no tubes or transformers) is good for slightly more advanced builders, and maybe more sales, as it's not such a big up-front expense for people.

Personally, I'd set up a simple website w/ some basic info and parts list w/ part numbers from a couple of electronics distributors, and just sell the PCB's. Then the builder can simply order the parts list for an easy build, or choose different components if they want.
 
Bespoke Constructor
Joined 2006
Paid Member
Hi

Some more pics as the 1st PCB has now been fully populated, next stage is to add to the main chassis plate and connect all the switches and transformers. Also note I have mounted the 10 ohm cathode resistors off board for easy change out in case a valve pops .. which normally takes out the resistor. These are sized for 1w only as a safety feature, so they go open circuit as not to cause any more pcb track damage.

regards

Nick
 

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nick
wonderfull work
the PCB is populated as an art work
I notice that you have increased the value of HT capacitors.
But to be very efficient we should introduce a couple of resistors between
the capacitors an as the PSB is done it is impossible.
How long have you been involved in DIY to do things so neat?
Congratulations