| Tyimo |
Hi!
After couple of months of the Lovoltech fever and heavy grup buys, I would like to know who built the ZV9 already???
What are the oppinions, experiences, listening test?!?!?
Greets:
Tyimo |
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| steenoe |
Tyimo, I ask myself the same question;) As to your question about anyone building the ZenV9, take a look here:D :
http://www.diyaudio.com/forums/show...8974#post888974
The sound is just amazingly good from that amp, the topend is just smooth and great:) The only little catch is the limited power-rating of 2x 15 watt's. My main speakers are rated at 82dB sensitivity and my second pair are rated atn 86 dB. The ZenV9 sounds great with my second pair:) Which are ProAc 1s clones:)
On another note, I hate to think that I am actually the only one building stuff around here??:o :o
Steen:cool: |
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| steenoe |
Bas, that doesnt look bad at all:) Any idea what the prices are like??
Steen:cool: |
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| Bas Horneman |
- 2HE (88mm high) width 435mm depth 300mm € 119,-
- 3HE (135mm hoog) 435mm breed 300mm diep € 149,-
- 4HE (180mm hoog) 435mm breed 300mm diep € 169,-
- 4HE (180mm hoog) 435mm breed 400mm diep € 199,-
Hi Steen,
It's on the page as well...but I'll do a translation (just of the first sentence ;)
The handles are € 32,50 per pair. i.e. not included in the prices mentioned above. |
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| harryeng |
And if you are wondering: The version with 18 CM high and 30 CM deep will result in 47 degrees celcius when running a standard Aleph 5.
The largest one can dissipate 400 Watt.
Rick is really into the Pass scene. On my request he even added a 2x60V, 2x12V 120 VAC encapsulated transformer to his goodies. Great for the Kari boards!
Greetings, Harry |
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| DocLorren |
| I can also recommend this company. Quick to reply on emails, focussed on what we like and nice products for a reasonable price. (no affiliation whatsoever btw.) |
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| Magura |
I threw a quick ZV9 together a couple of days ago, but wasn't particulary impressed with it, so it had a real short lifespan. At this moment I'm playing around with a mutation of the ZV1 which is heavily biased and using a different bias circuit, it sure sounds better to my ears than the ZV9.
Magura :) |
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| Bas Horneman |
| quote: | | I threw a quick ZV9 together a couple of days ago, but wasn't particulary impressed with it |
So...what are you going to do now with your power jFet's?:angel: |
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| Magura |
| quote: | Originally posted by Bas Horneman
So...what are you going to do now with your power jFet's?:angel: |
For now I will limit myself to making an all jfet balanced single ended amp, something like ZV7, just jfet and lower rails.
Besides that I have planned to make a cascoded version as well, so I am actually in the market for a few more jefets, I only got like 30 or 40 of them.
Magura :) |
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| Tyimo |
Hi!
Thanks Steen for the answer!
| quote: | | The sound is just amazingly good from that amp, the topend is just smooth and great |
It is doesn't augurs very well.... What about the bass and the mids etc. ?!?
Magura!
| quote: | | I threw a quick ZV9 together a couple of days ago, but wasn't particulary impressed with it, so it had a real short lifespan |
That was about I am afraid! ;)
Tyimo |
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| stefanobilliani |
| I have mine from months , and it is my favourite zen . With some dsd recording it just amazed me . I putted 4 switches for easily convert it from current source to voltage Aleph ( and viceversa ) , with my FE206 Fostex drivers MLTL speakers . Cant stop to listen to it . |
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| XELB |
| I am awaiting for my order but I think this amp needs a very good output cap and a good trafo. |
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| stefanobilliani |
| Yes good caps and separated secondaries for each channel . |
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| Variac |
Stefano,
Might be helpful if you posted a diagram where to put the switches.
Simple I'm sure, but it would encourage people to actually play around with the circuit-even a little!! and that's a good thing! Especially now that circuit boards are being made and more will be building the amp I'm sure.
What are the advantages of each setting-any opinions? |
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| Paul Ebert |
| quote: | Originally posted by XELB
I am awaiting for my order but I think this amp needs a very good output cap and a good trafo. |
Anyone have recommendations? Also, how critical are the power supply caps?
Thanks. |
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| XELB |
| quote: | Originally posted by Paul Ebert
Anyone have recommendations? Also, how critical are the power supply caps?
Thanks. |
As in any amplifier, better the PSU caps, better the sound!
Remember, if you want "good DC" feeding your speakers, you have to feed your amp with "good DC"..... your amp it's committed to what you feed him.
If you always eat Macdonalds, don't expect to have good blood :D :dead:
In the output caps, I think I will use ELNA audio caps or Philips.
Blackgate should be perfect but they aren't cheap.
In the PSU I will go for Rubycon ;)
And 2x 650 VA trafo :D
PS: Hey Veteran, don't forget me hehehehehehe :D ;) |
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| Tyimo |
Hi Stefano!
| quote: | | I have mine from months , and it is my favourite zen . With some dsd recording it just amazed me . I putted 4 switches for easily convert it from current source to voltage Aleph ( and viceversa ) , with my FE206 Fostex drivers MLTL speakers . Cant stop to listen to it . |
It is getting to be interesting;)
Thanks for the comments.
Tyimo |
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| bontakun |
I've just started building mine. I am shocked at what 5% variance means for some of these resistors. Like the 0.47R measured as 1.1R or higher. Just surprised about that. I can mebbe post pics but I'm not sure how to. I lack the 4x15000uf/63V needed for the powersupply so any suggestions would be appreciated.
I went with the jenson 4pole for output coupling and N-type 100uf for the 220uf caps on the board.
Not very far into it, but I can take pics and such. I'm considering getting higher quality resistors for the 1.0 and 0.47 parts since the ones i install might be a bit off.
-Bonta |
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| Greg Erskine |
| quote: | Originally posted by bontakun
I am shocked at what 5% variance means for some of these resistors. Like the 0.47R measured as 1.1R or higher. Just surprised about that. |
It could also be your DVM. Some can't measure low values accurately. You could measure a few in series and see if the measurement makes sense.
regards |
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| Babowana |
| quote: | Originally posted by bontakun
I am shocked at what 5% variance means for some of these resistors. Like the 0.47R measured as 1.1R or higher. Just surprised about that.
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Don't be surprised. It is due to additional resistance through DMM.
I usually use the method as shown in the attached sketch, where
we could choose the resistors within about 1% tolerance.
:)
I hope this info will help. |
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| Blues |
| quote: | Originally posted by Babowana
Don't be surprised. It is due to additional resistance through DMM.
I usually use the method as shown in the attached sketch, where
we could choose the resistors within about 1% tolerance.
:)
I hope this info will help. |
Make sure you also short your probes to get its resistance...some meters can be calibrated or zeroed to compensate the R of the probes. |
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| MikeW |
| I thought mine was a little flat so I changed the feedback resister to 100k. I also put a buffer in front of the amp. With the amp it has the same gain as a normal amp 28 or so db. The ZV9 is a very nice sounding amp. I woud like a couple more watts. :devilr: |
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| GRollins |
| quote: | Originally posted by MikeW
...I woud like a couple more watts. :devilr:... |
I'm working on it...I'm working on it...
Them what's in a hurry can build a New-Tron. But that doesn't mean that there aren't other designs coming. Just got Logan put down for a nap. The rude little feller wanted to be fed. Imagine that!
Grey |
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| Babowana |
| quote: | Originally posted by Babowana
Don't be surprised. It is due to additional resistance through DMM.
I usually use the method as shown in the attached sketch, where
we could choose the resistors within about 1% tolerance.
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Kkkkk hhhhhhhh . . . I was wrong. Very sorry.
I should have wrote down as +/-5% tolerance. :devilr:
I have thought another way to find similar values in five groups
I hope the attachment will well explain what I have thought about.
Of cource, if we have expensive precision ohm meter,
it would be the best solution . . . :) |
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| flg |
| More watts, ay Grey... Can't wait to see it... I've got a more watts circuit that seems to work, just not with the Aleph CS. I'm using L loading instead. Trying to work out a means to acquire the ideal L :confused: :confused: :confused: |
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| GRollins |
flg,
Wind your own. Inductors are one of the few things we can make for ourselves.
I told my wife today that I feel as though I'm trying to pave a mile of road. Just a single mile. But...I'm only able to pave one foot per day, perhaps two feet if I'm lucky. The goal is clear. The execution is easy enough. But that 1'/day limitation is killing me.
Oh, well. If life were easy, I'd be like the hare--I'd get so far ahead that I'd take a nap and that wily tortoise would scoot past me.
Maybe I should simply plan on being the tortoise.
Grey |
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| flg |
Yes, I realize that. However, although I've collected lots of useful components over the years, hundreds of feet of magnet wire wasn't one of them. Nor was any sort of core that might allow the use of less wire... :bawling:
So, I wrote hammond regarding their 195T5 choke and it's suitabiliity to my project... No response yet??? But I think it might do the trick :confused:
Just don't have the $$$ to go to far with this idea right now and it seems like the big 100mH DC choke is as cost effective as any...
Got an interview tomorrow :D :D :D Maybe I'll get back to some income soon :smash: :smash: :smash: |
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| GRollins |
Two words:
Surplus sites
MPJA and MECI for starters. Search keyword= Ferrite.
If need be, get your wire locally from motor shops, etc.
Grey |
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| flg |
Yea, Thanks grey. I've seen some better units at other surplus places but the price of those 195T5's looks pretty good. And maybe their applications expertiese will help me out too...
The interview went well today. I might be part of the taxpaying public again soon. They called me 2 hours latter. :D :D :D
So, what "mo Watts" idea with ZV9 are you working on???Com'on :bigeyes:
You've probably seen my L Loaded ZV9 thread. It works and sounds pretty good for now, thanks to N.P.s work. The gain is a little low though. (Actually 1/2 what I commented on in the thread, my mistake) The low freq's could be better too, but that's all in the L... I will have to rename it the SEJ (Single Ended JFET) Amp :D |
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| GRollins |
Cascode, yes. (Can't really do higher power amps without doing so.)
Zen9, no.
I have something else in mind.
Grey
P.S.: Has anyone gotten around to bridging these boogers yet? Surely that's an easy enough project. |
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| flg |
I haven't seen one(bridged), but I posted an idea for a ZV9-T or two. I didn't get around to building any of them due to moving and job hunting etc. etc.
I've built a dual JFET gain stage with a Z4 style buffer that does more Amps and more gain. :D I've tried several power trafo primaries but none able to deal with the saturation problem well enough for my liking. I'm hoping to try one of those Hammond 195 series chokes when I can scrap up the $$$ :D :D :D |
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| Variac |
| A working balanced scheme would be mighty cool- to use optimally with my BOSOZ. Also shouldn't be hard. |
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| GRollins |
If no one else steps up to the plate, I'll put it on my list of things to do. The problem is that it'll be about the 12th of Never before I get around to it. I've got two crossover updates, a preamp, and three power amplifiers all on the front burner, plus a repair, and...naturally...all the other things I do.
Jeez, if they'd only let me bring in oscilloscopes, soldering irons, resistors and all to work, I could get something done. Bummer.
Grey |
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| Zen Mod |
| quote: | Originally posted by Variac
A working balanced scheme would be mighty cool- to use optimally with my BOSOZ. Also shouldn't be hard. |
yup
it's possible to make it as CCS-X-BLS
with or without modulated upper ccs-es.......in short withALeph upper CCS-es or with plain ones.........variations ;)
if I'm not completely wrong.......as illustration -look at pic |
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| Mjjg |
Not sure if this is the proper place for this but I didn't want to start a new thread about it, and I am kind of a Zen 9 builder, though not finished yet.
Cred to veteran for his zen pcb but I wanted a board with all transistors on one side so I could mount all 240s with one bracket (+ some other things that I needed to change), so I whipped this up last night. It's probably not even near a perfect layout, so I humbly ask for input.
www.student.itn.liu.se/~andja285/Zen v.9.pdf
(Server is down from time to time, sorry about that. To big to attach)
Thanks... |
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| flg |
Mjjg, you sound like as much of a ZV9 builder as I am... But, the server must be down???
My current circuit is only partially ZV9 I would say... |
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| Nelson Pass |
A useful experiment for you to try on that circuit would be
to compare the performance of the Drains of the JFETs
tied together (as in your schematic) and not. If they are not
tied together then you can dispense with the Source resistors.
:cool: |
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| flg |
Thanks, I will give that a try :D I currently have some poor matching in the existing circuit so it needs a liltle work anyway.
:smash: :smash: :smash: |
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| bigbrowncow |
| quote: | Originally posted by Tyimo
Where are the ZV9 builders??? |
Yay! Finished mine today! Both channels working with a twisted pear kookaburra as the volume control.
I'll post some pictures of the box all put together nicely...
Steve |
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| bigbrowncow |
Some pictures as promised.
Initial listening impressions - it matches very well with my Austin FE166s. Everything we have listened to sounds like we are hearing it for the first time...Stravinsky, Ozric Tentacles, Mahler, Art Tatum.
I'm also quite pleased with the look, although I wish I'd thought of a neater way to do the wiring...
Woo! Still listening to the music :)
Steve
 :) |
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| Variac |
Love the look of it. A real Tough Guy amp! I think the knob needs to be an old fluted bakelite type though! maybe something like this:
http://www.fairradio.com/catalog.ph...ewitem&item=757
I always admire the guys that get these project done- congratulations.
Variac |
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| thomaseliot |
| quote: | Originally posted by bigbrowncow
Some pictures as promised.
Initial listening impressions - it matches very well with my Austin FE166s. Everything we have listened to sounds like we are hearing it for the first time...Stravinsky, Ozric Tentacles, Mahler, Art Tatum.
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Congratulations Steve :cool:
Nice compact placement of boards in a cube!
Now we are half a dozen of ZV9 builders. I agree with incredible sound, if speakers have enough SPL. |
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| steenoe |
Nice amp Steve, congrats:)
The ZenV9 fanclub seems to be growing steadily as it deserves:)
Steen:) |
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| Vix |
Hi,
It would be nice to know which speakers work best with ZEN V9...
I have two sets at the moment, Visaton B200 in a sealed box, and B&W 601. Visaton sounds better but has some problems of its own (it is a bit too forward in the upper midrange)...
I'll try V9 with Fostex FE 206. Currently they are in a box waiting for a decent enclosure (read BIB)...
What speakers are you guys using?
Regards,
Vix |
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| thomaseliot |
Hi,
I use FE206 in a TL enclosure. With ZV9 I discovered unsuspected bandwidth out of them, but sometime I still suspect these speakers to limit what ZV9 is able of.
A BIB with FE206 would lead to a big enclosure (see picture) and I don't know if it would add efficiency to drivers.
(The non standard shape is because otherwise the FE206 would be at 130 cm from floor - it must be placed at 90cm from sealed end)
Horn enclosures would improve drivers efficiency. An Oris front Horn is able of 102dB (1W 1M), but it needs an active woofer. What about an Hedlund or Carfrae clone (108dB/W/m)? I've no space for Pass Kleinhorn :bawling: |
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| steenoe |
I have used the ZenV9 with my Proac clones, but they are not efficient enough. I am making a pair of Abby clones with Fostex Fe166's right now, that will be placed in a small'ish room. i would expect that combination to sound pretty good. I am looking forward to try the ZenV9 as a current source amp, with the Abby clones also:)
Steen:) |
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| Vix |
| quote: | Originally posted by steenoe
I have used the ZenV9 with my Proac clones, but they are not efficient enough. I am making a pair of Abby clones with Fostex Fe166's right now, that will be placed in a small'ish room. i would expect that combination to sound pretty good. I am looking forward to try the ZenV9 as a current source amp, with the Abby clones also:)
Steen:) |
Steen,
I am also thinking to experiment with V9 as a current source. I used to run my V8 without feedback. On the one hand, the sound was more open and relaxed, more spacious with more micro details, musical, but on higher volumes I could notice some unpleasant distortion. On the other hand, when I run it with feedback, the sound was more solid, controlled, somehow cleaner, but a bit lifeless. Please let us know about how it sounds to you.
Abbys seem to be nice speakers.
Beside a BIB, I am also intrigued by Sachico: http://www.frugal-horn.com/spawn.html
although it is more difficult to build than a BIB. Also thinking about more fancy solution with Visaton B200 (open baffle)....
:cool: |
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| steenoe |
Vix, I think that using the ZenV9 as a current source amp with speakers that doesnt need the damping that the feedback brings,
should make for a large and detailed soundstage. In addition the clean and detailed topend of the J-fet adds to the soundstage too, well thats the hope anyways;) Time will tell.
Nice homepage of Planet10's. You have to give those guys over in the fullrange forum, that they does a great job indeed.
Impressive work, so why not take advantage of it.
I might try a pair of Iris or BIB's, some day.
Will report back, with listening impressions on the Abby-clones:)
Steen:) |
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| Peter Daniel |
Today I connected the tweeter (Aurum Cantus ES G1) directly to the amp through 6.8uF Siememns MKV cap only (the midrange was connected through BG N 1000/50 cap), no other electrolytics at amp's output have been used.
If you run your tweeters through those large electrolytics, you really don't know what Zv9 is capable of ;)
The focus, delicacy, definition and resolution of highs are truly impressive. |
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| t3447ml |
My Zen V9:
Main and PS capacitor boards courtesy of P. Daniels and D. Antoniak.
JFET courtesy of G. Rollins, thanks guys.
Side mounted heatsinks are made from surplus units each measuring 6.5" H x 5" W x 2.75" Fin.
Two and a half units make up a side.
Q2 and Q3 are each mounted to a unit, Q4 is mounted to half a unit.
JFET Q1 is mounted to the internal heatsink mounted across the chassis.
PSU/channel
Trans 250VA 18v+18v Avel Lindberg
Capacitor bank (4) 10,000uf 63V Panasonic TSHA
Using Fostex FE 108E Sigma in a backloaded horn the sound is very clean and clear.
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| Vix |
Zen V9 is an impressive amp. Now I started thinking about improving other components along the chain...
Maybe slightly off topic, but, I consider its quite important. Preamp. I'm using V9 with BoZ. Ok, that's fine. (even though my BoZ is using IRF530). But...I realized that, while BoZ is a very good preamp, I don't need that much gain. So...:scratch:
Is it possible to reduce the gain of BoZ and improve performance (more air...:devilr: ). Add a CCS instead of a resistor , or..err...
By the way, what preamps seem to be good mates to V9? What are you using as a pre?
P.s. Nelson, I feel guilty. You give us something good, and we want better. You gave us the Zen , then BoZ. Happy marriage. Now, Zen V9 wants mo'....:D :cool: |
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| Nelson Pass |
Of course you do. Otherwise I would retire to Sea Ranch and
you would not hear from me again. ;)
I think there is general agreement that the Balanced Line
Stage in the Zen series is better, even for single-ended
applications, so I suggest that.
:cool: |
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| adwsail |
Well my boards are all stuffed, the Conrad heatsinks are on order and the speakers waiting!!! Has anyone determined if 2 250VA 35v xformers are preferred over a single 500va hunk of iron??
My V9 will be tested on a pair of Decware HDT's, around 96dB/watt which should be a decent match. Preamp duties are handled by an antique old NAD 1700 or BOZ with CD's covered by a Njoe Tjoeb 4000. I've got a Tubelab SE 300B tube amp on the HDT's right now and I'm real curious just how the 2 amps will compare on the same speakers.
There was a wiff of info regarding running the V9 as a zero feedback current souce amp into high efficiency speakers but I can't seem to find any more detailed info. Is this something that needs to be looked into further???:rolleyes: |
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| thomaseliot |
| quote: | Originally posted by Nelson Pass
I think there is general agreement that the Balanced Line
Stage in the Zen series is better, even for single-ended
applications, so I suggest that.
:cool: |
Somebody has any hint on proper implementation of this balanced line stage with ZV9? |
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| Vix |
Hi,
As I was worrying about a preamp to be mated with ZV9, I have tried something....Just yesterday I have finished a 6922 tube buffer (cathode follower biased with Jfet CCS. It sounds marvelous!
The gain is lower, but I'm not worrying about it now. It is quite loud. If I am not mistaken, ZV9 should have around 12 dB of gain.
Nelson, I think I have read somewhere that F3 has a somewhat higher gain than ZV9 (15 db?) and a different percentage of AC current gain?
By the way, is it too early to expect an F3 service manual?
Steen, did you try ZV9 as a current amp, or you put that idea aside? (I know that you're busy building an F4):devilr:
Regards,
Vix :) |
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| Nelson Pass |
F3 has a 12.5 dB gain as currently shipped. The current
source gain is trimmed to achieve exactly that figure.
:cool: |
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| Vix |
| quote: | Originally posted by AUDIOTECH1
I see you always talk about Zen amplifiers, your not the only one so do a lot of my friends could you explain why are they so good? |
I don't bother myself with the questions of why do Zen amps sound good-they simply do. (Especially Zv9) Build one and you'll hear.
I have one question: Did anyone do distortion measurements of F2 and ZV9 without feedback (and without Aleph CCS)?
F2 is a good transconductance amp, however "feedbackless Zv9" should make for even a better one. (both on paper and listening)
Thanks,
Vix |
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| Vix |
Hi
In the F4 thread Nelson answered that he uses an F3 as a stock amp, not as a current amp, as I thought. I decided to jump to this thread. It seems more appropriate. I didn't want to go far OT on F4 thread.
Nelson, thank you very much for a reply. I was expecting the opposite answer though. Can't say I am not surprised. Didn't you like F3 as a current amp? Was it showing signs of instability, or was it just a matter of taste?
On one hand, one could say that "F1 and F2 are current amps, if you like them, build 'em." F3 is a a voltage amp with low distortion. On the other hand, F3 as a current amp shouldn't have any more distortion than an F1 or F2, plus it will have that Jfet sound.
What will happen if there is a minimal (3 db) of feedback? (vs no feedback at all) I guess that it should behave as a voltage amp with highish output impedance. I am considering this as an alternative to the "no feedback" solution.
Thanks,
Vix
p.s. Happy Easter! |
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| Nelson Pass |
| quote: | Originally posted by Vix
I have one question: Did anyone do distortion measurements of F2 and ZV9 without feedback (and without Aleph CCS)?
|
| quote: | Originally posted by Vix
Didn't you like F3 as a current amp? Was it showing signs of instability, or was it just a matter of taste?
What will happen if there is a minimal (3 db) of feedback? (vs no feedback at all) I guess that it should behave as a voltage amp with highish output impedance |
So many questions this morning. Of course the F2 has no
feedback already, so the documentation on it answers one
question. Different versions of what became the F3 are shown
in ZV8 and then ZV9, including versions with no feedback and
minimal feedback, and there are distortion curves giving some
examples of those.
In my business I have learned to concentrate on one story at
a time, otherwise people get confused and the point is lost.
The F1 and F2 were current sources, one balanced, the other
single-ended. The F3 is a power JFET. You make make very many
permutations of combinations these techniques, but I leave that
to you for the most part. At present I want to spend more time
on core ideas.
:cool: |
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| Vix |
| quote: | Originally posted by Nelson Pass
You may make very many permutations of combinations these techniques, but I leave that to you for the most part. At present I want to spend more time on core ideas.
:cool: |
Thanks! Chapter F3 finished, time for an exercise! (cutting the feedback resistors) :) :cool: |
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| Vix |
Hi!
I just cut the feedback resistors on my ZEN V9, (and disconnected the Aleph CS). I connected load resistors across the output.
Interesting thing happens: As I try various values of output resistors, sound quality changes. I don't know how to describe it. While trying different values, there seem to be some which "just sound right". At the moment, it is loaded with 7.5 Ohm (2x15 ohms in parallel). It seems to work best for me. I guess it is a matter of adjusting the output impedance, hence damping, bringing it to a "correct" amount.
Speakers are Visaton B200.
Happy listening,
Vix |
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| Zen Mod |
| quote: | Originally posted by Vix
Hi!
I just cut the feedback resistors on my ZEN V9, (and disconnected the Aleph CS). I connected load resistors across the output.
Interesting thing happens: As I try various values of output resistors, sound quality changes. I don't know how to describe it. While trying different values, there seem to be some which "just sound right". At the moment, it is loaded with 7.5 Ohm (2x15 ohms in parallel). It seems to work best for me. I guess it is a matter of adjusting the output impedance, hence damping, bringing it to a "correct" amount.
Speakers are Visaton B200.
Happy listening,
Vix |
oh,boy.........I just can't resist with off topic..... :devilr:
what you else tried lately,besides B200 ? |
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| Nelson Pass |
| quote: | Originally posted by Vix
I just cut the feedback resistors on my ZEN V9, (and disconnected the Aleph CS). I connected load resistors across the output.
Interesting thing happens: As I try various values of output resistors, sound quality changes. I don't know how to describe it. While trying different values, there seem to be some which "just sound right". At the moment, it is loaded with 7.5 Ohm (2x15 ohms in parallel). It seems to work best for me. I guess it is a matter of adjusting the output impedance, hence damping, bringing it to a "correct" amount. |
That's the spirit. :cheers: |
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| Magura |
| quote: | Originally posted by Vix
Hi!
I just cut the feedback resistors on my ZEN V9, (and disconnected the Aleph CS). I connected load resistors across the output.
Interesting thing happens: As I try various values of output resistors, sound quality changes. I don't know how to describe it. While trying different values, there seem to be some which "just sound right". At the moment, it is loaded with 7.5 Ohm (2x15 ohms in parallel). It seems to work best for me. I guess it is a matter of adjusting the output impedance, hence damping, bringing it to a "correct" amount.
Speakers are Visaton B200.
Happy listening,
Vix |
I have pretty much the same standing at my livingroom floor, but developed a little further and based on a ZV1 that got a cascoded JFET and very little local negative feedback, no global negative feedback. I for some reason don't like the aleph current source, so I have used the current source from the ZV1 and used the cascode and the cascode modulation is close to what is seen in ZV9. I have upped the bias to 4A and the rail voltage is upped to 44V.....anturally it only survives due to some pretty massive heatsinking. Oh and I have substituted IRFP240 for IRFP044.
I use the amp for powering my Abbey clones.
Magura :) |
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| Zen Mod |
| quote: | Originally posted by Magura
..................anturally it only survives due to some pretty massive heatsinking. ..................................
Magura :) |
heavy heatsinking ........when you build..........?
nah................
:clown: |
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| Magura |
| quote: | Originally posted by Zen Mod
heavy heatsinking ........when you build..........?
nah................
:clown: |
Well, in this case it's heavy heatsinking....even in my book! I tell you it's a pair of serious heatsinks. The same amount of heatsinking per channel as Steenoe is using per channel for his AX-100 monoblocks :bigeyes:
....and they run HOT!
Magura :) |
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| Zen Mod |
| quote: | Originally posted by Magura
Well, in this case it's heavy heatsinking....even in my book! I tell you it's a pair of serious heatsinks. The same amount of heatsinking per channel as Steenoe is using per channel for his AX-100 monoblocks :bigeyes:
....and they run HOT!
Magura :) |
and-just for record..........can you tell me estimated cost of that heatsinking stereo pack?
:devilr:
(I know that I'll not be sole impressed) |
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| Vix |
| quote: | Originally posted by Zen Mod
oh,boy.........I just can't resist with off topic..... :devilr:
what you else tried lately,besides B200 ? |
Not much. A few years ago I started playing with fullrange speakers, and fell in love with them. I tried various car speakers (pioneer, philips, blaupunkt, and some no-names). Then I had decided to go with something "more serious" and got a chance to buy a pair of Fostex 206. Built an ML TL (M.J. K' project 5). Last december I got a chance to buy Visaton B200, and couldn't resist. Took Fostex out, mounted Visatons and filled the port with foam, so it would act more like sealed box. Despised Visatons at first, they were screaming at me.
At the same time I was having fun with pass amps. Built F2 lite and ZV9. Bride of Zen could no longer satisfy the new Zen variation, so it got retired. A Sovtek 6922 cathode follower took its place.
So, where I am now: I got a transconductance ZV9, Cathode follower as a pre, and Visatons as main speakers. They still scream, although not that much. ( I applied passive EQ network). Geoff H at fullrange forum http://www.diyaudio.com/forums/show...&threadid=99662
did us a favor and designed a PLL circuit to equalize B200's response. Now that I have modified ZV9 into a current amp, I have connected 100 Kohm resistors at the input. If a am not mistaken, this should be its input impedance, that would enable the use of Geoff's PLL circuit, between a pre and ZV9. Didn't have the time to try it today, most probably it will have to wait till the next weekend.
By the way, Fostex-es are still in a box. I don't see a point in connecting them now. They are waiting for a BIB. Way Off Topic: I moved some furniture these days. Now I have enough space for either an OB, or a BIB. The problem is that I want both...
:devilr:
| quote: | Originally posted by Nelson Pass
That's the spirit. :cheers: |
Thanks!
:cheers: :) |
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| Vix |
| quote: | Originally posted by Magura
I have upped the bias to 4A and the rail voltage is upped to 44V.....anturally it only survives due to some pretty massive heatsinking. Oh and I have substituted IRFP240 for IRFP044.
I use the amp for powering my Abbey clones.
Magura :) |
44 V times 4A.. :hot: :hot: :hot:
I'd be afraid to run it that high. Nevertheless, if you manage to cool it, it should be well worth...
:cool: |
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| Magura |
| quote: | Originally posted by Zen Mod
and-just for record..........can you tell me estimated cost of that heatsinking stereo pack?
:devilr:
(I know that I'll not be sole impressed) |
I get them for cheap, so it's not that bad. Some 250 EUR or so.
Magura :) |
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| Zen Mod |
| quote: | Originally posted by Magura
I get them for cheap, so it's not that bad. Some 250 EUR or so.
Magura :) |
why I was in impression that you made them ?
anyway-they look good as that you made them........ :D
btw-where's steen this days......it's sorta quiet without him........
seems that he mention vacation........ |
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| Magura |
| quote: | Originally posted by Zen Mod
why I was in impression that you made them ?
anyway-they look good as that you made them........ :D
btw-where's steen this days......it's sorta quiet without him........
seems that he mention vacation........ |
The last I heard from him was something about a vacation someplace warm...let's hope it rains where he went ;)
The heatsinks Steenoe has are not made by me, those are just from the supply of heatsinks I bought to get the DIY stuff going here in Denmark a few years ago....the ones you can see in my gallery are made by me. The ones in the gallery are based on the design of the ones Steenoe has. I figured it would be a lot of trouble to do the math for designing a heatsink myself.
http://www.briangt.com/gallery/Heatsinks/PICT0099
Magura :) |
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| Zen Mod |
| quote: | Originally posted by Magura
The last I heard from him was something about a vacation someplace warm...let's hope it rains where he went ;)
The heatsinks Steenoe has are not made by me, those are just from the supply of heatsinks I bought to get the DIY stuff going here in Denmark a few years ago....the ones you can see in my gallery are made by me. The ones in the gallery are based on the design of the ones Steenoe has. I figured it would be a lot of trouble to do the math for designing a heatsink myself.
http://www.briangt.com/gallery/Heatsinks/PICT0099
Magura :) |
so -I was right,even if I can't remember that I read somewhere that they are made in your shop ...... I asked not meaning on money primary involved,but cost of your work ........as a illustration of passion involved
hat off to metal guru ;) |
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| Magura |
| quote: | Originally posted by Zen Mod
so -I was right,even if I can't remember that I read somewhere that they are made in your shop ...... I asked not meaning on money primary involved,but cost of your work ........as a illustration of passion involved
hat off to metal guru ;) |
Well, the cost of my work is a very flexible matter....As I have access to pretty much any type of equipment for free, what I'm counting then is time spent. As I recall those heatsinks has like 20 CNC machine hours on them each (at least, probably more) and like 50 or 60 hours to do the design and the finish. There are 12 in total.
Magura :) |
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| Vix |
I'm almost convinced....I'll do OB's first, then, if I really miss the bass, I may do BIBs...
Thanks for the links.
p.s. SFR200 doesn't look bad
:) |
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| Vix |
Oh, somehow I missed that thread. Interesting info there. Will read it tonight, and shake my head once again :devilr:
I hope we haven't gone far OT...but...These speaker projects are intended to be used with ZV9 ;) |
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| Zen Mod |
| quote: | Originally posted by Vix
Oh, somehow I missed that thread. Interesting info there. Will read it tonight, and shake my head once again :devilr:
I hope we haven't gone far OT...but...These speaker projects are intended to be used with ZV9 ;) |
don't shake y'r head......go and buy Beta15 ,make your version of NOBOX and enjoy........
btw-my middle name is OT :devilr: |
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| Magura |
| quote: | Originally posted by Vix
44 V times 4A.. :hot: :hot: :hot:
I'd be afraid to run it that high. Nevertheless, if you manage to cool it, it should be well worth...
:cool: |
It sure is well worth it...I just don't expect the mosfets to have a particulary long life in this application. Surprisingly those FET's are soon to have one year birthday :) runnig an average of like 4 to 5 hours a day. I sure didn't expect that. The JFET's are too pushed very hard, and they are soon to be half a year old in that amp.
Anyway, the sound is about as sweet as it gets in my opinion without resorting to differential pairs and inductors. For the Abbey's it beats any amp I have tested so far. That includes an AX-100, a mini aleph and a bunch of commercial gear.
Magura :) |
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| Zen Mod |
| quote: | Originally posted by Magura
It sure is well worth it...I just don't expect the mosfets to have a particulary long life in this application. Surprisingly those FET's are soon to have one year birthday :) runnig an average of like 4 to 5 hours a day. I sure didn't expect that. The JFET's are too pushed very hard, and they are soon to be half a year old in that amp.
Anyway, the sound is about as sweet as it gets in my opinion without resorting to differential pairs and inductors. For the Abbey's it beats any amp I have tested so far. That includes an AX-100, a mini aleph and a bunch of commercial gear.
Magura :) |
isn't possible to double number of jfets and m'sfets ? |
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| Magura |
I guess it is, but with a capacitance penalty....and it's also not as much fun ;)
Magura :) |
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| Vix |
:scratch:
I was scratching my head and wondering whether I correctly assumed the feedbackless ZV9 input impedance. I removed feedback and connected 100 K resistors across the inputs. I guessed that the input impedance will then equal 100 K.
(I needed 100K input impedance because of the PLL filter I applied).
Or Not...:scratch: :headbash:
Maybe I'm wrong...
Please someone :bulb: me... |
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| Zen Mod |
| quote: | Originally posted by Vix
....................
Maybe I'm wrong...
Please someone :bulb: me... |
OK-there is a :bulb:
you are not wrong..........
:clown: |
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| vdi_nenna |
You guys think this heat sink is big enough for a Zen 9? Looks a little small.
I want to stack 2 for one channel and put the CCS on one and Jfet and Fet on the other.
What do you think?
Thanks,
Vince |
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| vdi_nenna |
Dimensions:
10 3/4" long - 4 5/8" Wide and 1 5/8" Tall Flat Bottom - 18 Fins at 1 3/8" Tall
And another pic. |
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| GRollins |
Side by side will give you better heat transfer.
Grey |
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| vdi_nenna |
Umm. True that.
I was considering stacking because I have these 5"+ caps that I'd like to use. However, with 20"+ on depth, I could lay the caps flat too. Should be room for caps and transfos too.
That brings up another question: what's the voltage of the PS caps? I have about 20- 10k uf 35v caps...Nope. Needs 63v. I'll have to add them to the shopping list.
Thanks,
:D
V~ |
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| przemek_sad |
| I want to buy LU1014D transistors 2 or 4 pcs. Can anybody sell it to me? |
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| coffin |
My ZV9 at last.......
When a suitable chassis came up, the ZV9 amp was fired up!
LU1014D power JFET, which will be solder at the Copper plate
ZV9 PCB by PD & DA
Most resistors are BC's, with MUSE KZ caps and Blackgate F
I have to wire the JFET due to fragile pins of LU1014D
RIFA PEH169 22000uF/63V for power and coupling
Measuring voltages
Listening test
Still trying on different bypass cap
Thank you PAPA! |
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| Nelson Pass |
| You're welcome. I like seeing ZV9's get built. |
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| Peter Daniel |
As to the coupling caps, I tried it initially with Jensens 10,000/63 electrolytics and it sounded fine; I later added 0.1uF teflon caps in parallel and the sound improved in high frequencies although lost a bit in naturalness.
The big step forward however, was using separate coupling caps for tweeter and midrange drivers (in my case I use aditional amp for subs so midrange is limited to 100Hz or so). I used Siemens MKV 6.3uF for the ribbons and BG N 330/100 for midrange coupling (the only caps between amp and the drivers) and that creates the sound that is in a completely different league ;) |
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| coffin |
Nelson:
Thanks! You sharing is always a gift to DIY community!
Daniel:
Thanks for your PCB!
So there's only one ZV9 MKV+BG equipped and an additional subwoofer amp?
Or Two ZV9 equipped separately with MKV and BG?(and an additional subwoofer amp)
I'll try different bypass step by step.
cheers
Coffin:smash: |
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| Nelson Pass |
| Try the silk RFS Elna's. |
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