Penultimate Zen Hybrid

[kristijan-k]

Hello,

Here is one little different idea for the ZVP3310 subtitution - with
the E88CC/ECC88/6DJ8/6922 Valve.
I did not yet test this modified circuit, but as soon as
I found some time, I will give it a try and see how it will work.

Any comments or suggestions ?

Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

 

[Bricolo]

it would need 2 transformers
but it could sound great


PS: what's wrong with the ZVP3310?

 

[stan_nesta]

Kristijan,

I think in order to use e88cc as a buffer you should arrange it as a follower, that is the output is taken from the cathode, therefore no gain, no Miller capacitance, etc.

Regards

Stan

 

[kristijan-k]

Hello,

The two transformers are not a problem.
Also, the 50 V voltage from the unregulated
power supply can be tripled with the capacitors/diodes
to the 150 V or so.

Nothing wrong with the ZVP 3310, but the Zen with
the Valve would probably sound much different.

Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

 

[djk]

Almost 50dB of gain with an input impedance of 820 ohms?

 

[kristijan-k]

... or maybe something like this, with balanced inputs ?

 

[tschrama]

I like the idea, but I don't understand your schamtics. Are you shure you didn't make an error?

gr,
Thijs

 

[Tazzy]

Whow... Zen "Lite" Penultimate.

Kristijan, since I can't find ZVP3310's a change in this direction might be a pretty cool option.

Let me know how thinks work out and how a valve sounds nice
in this setup. I might want to buy a pair of PCB's from you.

 

[Tazzy]

The two transformers are not a problem.
Also, the 50 V voltage from the unregulated
power supply can be tripled with the capacitors/diodes
to the 150 V or so.

That would be nice, the torroids I bought (by mistake) for my zenv4's are 35-0-35 @ 300VA Amplimo's Torroid.

I was planning to use them as 35-0 @ 600VA.
Another option would be to use one secondairy for the valve(s) and the other for the "Zen".

 

[kristijan-k]

Hello,

Thanks for the response.

I will try to build the Zen-4 with tube on several ways,
and see how it would work.

I ordered the 6DJ8 tubes, together with the other ones
for the OTL that is on my website, and when they arrive
we will see if this is a good way to go.

Anyone know for the good program that can simulate
this kind of circuit ?

Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

 

[jean-paul]

Tazzy, you can replace the ZVP by a BS250 which is easily available and sounds better according some on this forum. Do a search for BS250 and you'll find info. If you're really desperate I can send you two of them.

 

[Bricolo]

Hello,

Also, the 50 V voltage from the unregulated
power supply can be tripled with the capacitors/diodes
to the 150 V or so.

http://web.vip.hr/pcb-design.vip

can you explain me how to do this?

 

[till]

http://www.e-online.de/sites/slt/schalt/06041711.gif


UA ~ 2 * 2 * US

 

[Tazzy]

What values for the parts would I need for voltage tripling?

 

[kristijan-k]

Hello,

Here is also one example with component values.


Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

 

[kristijan-k]

Hello,

I just tested several hybrid circuits (Zen-4 with tube), and I think
that I'll remember this experiment for a while.
I get shocked by electricity !!!!

That happened completely by my mistake, I builted the circuits
point-2-point I used all wires of the same color, than little rushed,
listen the jokes of my friend, and then ... buuuuuuuuuuu !!!

Be very carefull when working p2p and high voltage.

The first circuit that I posted (1/2 6DJ8 only) worked, but the gain is high and the sound is little fuzzy compared to the original Zen-4.

Also, you can forget for the power supply circuits that are
posted earlier.
They are noisy, and for the best sonic results the regular
power supply for the tube must be used.

But, the Zen-4 with tube that have balanced inputs (seccond
circuit diagram that is posted) worked wery well.
Instead 200 V power supply, I used 250 V (I used power supply from one other tube project ).
The sound is little different from the original Zen-4, there
is little more bass.
The circuit perform well with negative input grounded (unbalanced
input), but with the balanced inputs used it sounded better.
The gain of this circuit is similar to the original Zen-4.

I used Balanced Line Stage preamplifier with this version of hybrid
and it is working wery good with it.
I used volume potentiometer at the BLS inputs only, and there is
no any noise/hum problems.

Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip

 

[Coulomb]

Hello Kristijan, is this a project you might be thinking of producing a board for?

Anthony

 

[Tazzy]

How much VA's do a set of valve's need?
I saw that you used 50VA in the voltage tripler?

And are you going to make PCB's for the Zen Hybrid?

 

[kristijan-k]

Hello,

I used 190 V/20 VA transformer per tube, but you can get away even with the smaller one.
For the tube heater I used 9 V/10 VA transformer per tube.

I don't know yet if I will be making the PCBs for this Zen-4 Hybrid,
but if there would be interest, I can make a few of them.

I received several e-mails about tube pinouts, so here is also
one enclosed below.

Also, the Svetlana 6N1P tube can be used for this project, and it's
pinouts are the same as for E88CC/ECC88/6922/6DJ8 tubes.
The 6N1P tube is direct replacement for tubes mentioned above,
so no changes are neccesary to the rest of the circuit if it will be used.

Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design

 

[Tazzy]

My guess is that you've got at least 2 customers ;-)