| 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 |
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| Bricolo |
it would need 2 transformers :xeye:
but it could sound great :)
PS: what's wrong with the ZVP3310? |
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| 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 |
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| 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 |
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| djk |
| Almost 50dB of gain with an input impedance of 820 ohms? |
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| kristijan-k |
| ... or maybe something like this, with balanced inputs ? |
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| tschrama |
I like the idea, but I don't understand your schamtics. Are you shure you didn't make an error?
gr,
Thijs |
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| 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. |
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| Tazzy |
| quote: | Originally posted by kristijan-k
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". |
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| 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 |
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| 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. :) |
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| Bricolo |
| quote: | Originally posted by kristijan-k
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? |
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| Tazzy |
| What values for the parts would I need for voltage tripling? |
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| 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 |
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| Coulomb |
Hello Kristijan, is this a project you might be thinking of producing a board for?
Anthony |
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| 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? |
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| 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 |
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| Tazzy |
| My guess is that you've got at least 2 customers ;-) |
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| Coulomb |
| quote: | Originally posted by Tazzy
My guess is that you've got at least 2 customers ;-) |
Tazzy is correct, I have been looking for an excuse to build PZ4 and this MOD would be a good one. What would you estimate the price to be Kristijan? I would be interested in two.
Anthony |
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| kristijan-k |
Hello,
Anthony,
The PCB cost mainly depends on the PCB surface area,
and as I did not yet design it I can't tell precisely.
But, it should be somewhere in Aleph 3 / Aleph 5 price range.
The PCBs would be made the same way like the rest of boards
on my website (made of FR-4 fiberglass material with Cu-50 mikron + Pb track overlay (tinplated), laser drilled, with two sided blue soldermask, and with white component overlay).
I will also design proper power supplies for the Zen Hybrid, and
latter post them here and to my website.
Also, here below is final Penultimate Zen Hybrid circuit diagram,
that I tested and it is working excellent with the
Pass Balanced Line Stage preamplifier.
It is working very good with unbalanced inputs, but it is also
perform excellent with the balanced inputs.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
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| kristijan-k |
... well it seems that I attached wrong .gif file.
The final version should be like this : |
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| Coulomb |
| quote: | Originally posted by kristijan-k
... well it seems that I attached wrong .gif file.
The final version should be like this : |
If you were to design a board Kristijan, would the tube socket be mounted on the PCB? If so a horizontal mount would be desirable, how would the FETS likely be mounted. i would think a 2 pc design with a FEB and an output board would be the most practical?
Anthony |
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| Nelson Pass |
I appreciate what a nice circuit you've got there, but I
can't help but note that the impedances appearing at
the Gate of the Mosfet are pretty high, and as a result
will show quite a bit of distortion on the top end due to
Mosfet capacitance non-linearity.
Do you think you can get those values down and/or
put the feedback at the tube inputs so as to improve
this situation? |
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| kristijan-k |
Hello,
Mr.Anthony,
There would be just one PCB.
The tube socket would be mounted on the PCB.
This way the all connections would be as short as possible.
Mr.Pass,
Thank you for the suggestion.
I tried several more ways to improve this situation,
and there is always a compromise.
The new circuit sound much better, more cleaner,
but the gain little went down.
Also, this is no problem at all when using preamplifier.
This new circuit sound excellent, and is also
dead quiet when not playing.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
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| kristijan-k |
Hello,
And here below is tube power supply circuit diagram.
I used relays instead high inductivity inductors.
They are working excellent in this power supply.
The relays are standard ones, and they are more easier to get
than special inductors.
If someone would like to use special inductor instead relays,
than it should around 10 H / 50mA / 270 Ohm or similar.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
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| Tazzy |
I was planning to use:
with the 4x1200uF first and the 3x6800uF last for the "Zen" part of the amp. I know it wil work, but is it a good idea?
What is the purpose of those relays in the valve power section? |
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| kristijan-k |
Hello Tazzy,
As I already had a builted Zen Hybrid, I did not want to
wait a week or so to order and for arrival of 10 H inductors.
So, I tried with the relays that I already had at the hand.
Well, I can tell that they are working excellent in this power
supply.
The relays will not actually operate in this power supply.
I use here only relay coil as the inductor (with iron core).
The purpose of this inductor is pretty much the same
as those 2,2 mH in power stage power supply.
Instead relays you can use special high inductivity
inductors for the tube power supply, but the relays
already do they job more than enough, and are more
easier to find.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
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| Nelson Pass |
| quote: | Originally posted by kristijan-k
This new circuit sound excellent |
That was what I had in mind. Glad it worked for you. |
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| Ric Schultz |
I have found the the Aleph output stage does not sound very good compared to a simple current sourced stage. All the feedback around the current source, the out series resistors, all the parts hanging on the output all mess up the sound royally. A simple Mosfet with a fixed current source sounds way better. You do lose the power into 4 ohms and lower but it sounds soooo good.
Another simple output stage you could try would be a simple push pull, class A, no feedback Mosfet stage. You could simply run two caps off the the plate of the tube (one per phase) and bias the mos-fets off of the power supplies of the mosfets. Very simple (4 resistors and 2 pots per channel does the trick. With a push pull class A stage you bias it for whatever power your power supply, transistors and heatsink can supply but it will deliver much more power in AB, so it will drive lower impedance, less sensitive speakers. A single tube driving a two pairs of mos-fets can deliver over 150 watts into 4 ohms. You can bias it for 5-25 watts or higher.
I don't know how to post circuits here or I would.
I can fax you the circuits if you like.
Ric Schultz |
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| Nelson Pass |
If you follow this to its logical conclusion, you end up with
a resistor for a current source, as with SOZ or Zen Lite. |
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| Joe Berry |
| quote: | Originally posted by Ric Schultz
I don't know how to post circuits here or I would. |
Ric -- after composing your reply, click the button labeled Browse... (located just above the Submit Reply button) to open a directory of your system files. Then choose the graphics file you want to post. |
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| Tazzy |
Kristijan, any news on the PCB's?
Anyway, for what parts in your the design does it make sense to use a better/more expensive part? |
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| deming8418 |
Ric schultz
I'm interesting in your opinion about output stages.Can you send me the circuit.
My e-mail: deming8418@sina.com
Thanks a lot. |
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| Tazzy |
| Kristijan could you post a picture of the amp? I'd like to know how big it turned out :) |
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| kristijan-k |
Hello,
Except tube, the amplifier use pretty much the same components
as original Penultimate Zen 4 from Mr.Pass, and you can use the
components of similar quality and have excellent results.
The Tube Penultimate Zen use one E88CC (ECC88, 6922, 6DJ8, 6N1P)
tube per one channel-monoblock, and here it does make sense to
buy two matched tubes, so you can have even more identical channels.
The E88CC is of high quality, and it even have goldplated pins.
The heat dissipation and the overall size of the Tube Penultimate Zen
amplifier is very like the original Zen-4 of Mr.Pass.
I finished designing the PCB, and the all parts including tube are located
on the one PCB. The tube use B9A PCB mounting socket,
like shown on attached picture, it is also available with goldplated contacts.
The PCBs are already available at the website below, and are of high
quality, like the Aleph PCBs.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
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| Tazzy |
| Since I'm still building mine I'm wondering if there are any know improvements for Kristijan's hybrid design? |
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| Mach_Y |
| quote: | Originally posted by kristijan-k
Hello,
Here is also one example with component values.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
What I am curious about is the power section. Based off the pcb's on your site, you need 3 seperate power supply sections for each amp (assuming mono-blocks). Will you by chance be making a PCB that only uses 1 power supply? |
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| Jay |
<i>RIC SCHULTZ: “I have found the Aleph output stage does not sound very good compared to a simple current sourced stage. All the feedback around the current source, the out series resistors, all the parts hanging on the output all mess up the sound royally. A simple Mosfet with a fixed current source sounds way better. You do lose the power into 4 ohms and lower but it sounds soooo good.”</i>
I’m glad that I’m not the only one who thinks so! (I know now that the sweet vocal characterizing the Aleph came from the feedback)
<i>NELSON PASS: “If you follow this to its logical conclusion, you end up with
a resistor for a current source, as with SOZ or Zen Lite.”</i>
But I think the sound is different, a lot more bass (or power?) on the “Aleph”.
Kristijan-k, I’m hoping you will soon come up with tube differential stage to replace IRF9610 in the Aleph :nod: |
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| Mach_Y |
| quote: | Originally posted by kristijan-k
... and here below is wiring diagram for the Tube Penultimate Zen
amplifier.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
Kristjian,
What transformer is that in your diagram? Thanks!
Mark |
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| ashok |
Hi Kristijan,
Where did you get the B9A pcb mounting socket? Looks better than what I have or seen. How much is it and where can I get some. How much more is the gold plated version?
Thanks. |
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| kristijan-k |
Hello,
Mach_Y,
The transformer was custom made for me by local manufacturer.
The power stage requires around 38 V/300VA, and tube stage requires
170 V/10VA + 9 V/15VA for tube heater.
The power supply voltages are not critical, and If you are not able to find
the transformer/transformers with this
voltages, than feel free to use any that are similar.
The above power ratings are per one channel.
If you would like to use one power supply for the both channels, than
just double the power ratings of the transformers.
The tube power supplies are on the left down corner of the PCB, and
the power stage power supply is on the right up corner of the PCB.
Ashok,
The B9A pcb mounting socket is from Audiokit, Italy.
However, you can find them at a few places over the net.
I don't remember the exact cost of them, but I think that they were
a few euros per socket.
There is not much price difference between goldplated version,
but they are little harder to find.
You can contact the Audiokit by: info@audiokit.it
I also have two mounting sockets that I will not be using.
They are not goldplated.
If you would like them, please provide me your adress,
and I would send them to you.
Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design.vip |
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| Mach_Y |
Kristjian,
So a 170V @ 1 amp secondary and a 9V @ 1 amp secondary would be plenty, correct? Also, any thought on using the IRFP240 and boosting the power stage voltage for more gain as discussed in the pass labs articles?
Mark |
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| Tazzy |
Due to other priorities my penzenhybrid is still in the half finished state. The pcb is at 90%, the cabinet needs some work and I still need some connectors and electronical parts.
Last night while going through some spare parts I found this small block transformator which could be ideal for the 9v powersupply. One thing lead to another and I started thinking that I could use 1 psu for 2 amps in a seperate cabinate which I could use as a "remote" turn on console.
This leaves 1 question, ground loops... should I be worried when going for such a setup? |
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| Dr. ODD |
Hi Kristijan
Could you compare the sound of the Tube Zen whith the original Version?
Thank you
Bernhard |
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