Spot on Domenico. Though, I prefer tall, young, peasant-style, healthy, ellegant gazelles.
Yet, there is enough room for creativity and different design decisions:
One obvious viable candidate is garrbage's Black Board. I would like very much to purchase it when/if it will be available for group order. It seems to be still of the original concept with very well incorporated variations/improovements. I trust garbage's proficiency.
And by the way, we should encourage here diversity, creativity and initiative. From my experience I can say that sometimes seemingly a "stupid question" may contribute much more than a well founded ellaborate theoretical discussion.
@Paroxod4
I wish you all a pleasant Sunday afternoon.
Last edited:
Spot on Domenico. Though, I prefer tall, young, peasant-style, healthy, ellegant gazelles.
Yet, there is enough room for creativity and different design decisions:
One obvious viable candidate is garrbage's Black Board. I would like very much to purchase it when/if it will be available for group order. It seems to be still of the original concept with very well incorporated variations/improovements. I trust garbage's proficiency.
And by the way, we should encourage here diversity, creativity and initiative. From my experience I can say that sometimes seemingly a "stupid question" may contribute much more than a well founded ellaborate theoretical discussion.
@Paroxod4
I wish you all a pleasant Sunday afternoon.
you are right.
However, a DIY,
for example,
can opt for trimmer always in cermet instead of terrible coal or exaggerate with metal blade trimmer.
You can also think of constant current generators with regulator chips or current generating diodes with very interesting results on the noise figure.
2 examples among many , but 2 objective, non-subjective examples
Finally looked at the Dartzeel factory tour. One screen capture shows an amp partial schematic, seems to me that this thread NHB-458 schematic was quite correct. If the NHB-108 is a scaled down version of the 458, with two pairs of output, it shouldn’t be too difficult to make a test pub for it... Compare both pictures
Attachments
Let me comment on that
1 - Some of chinese boards are exact clone of the original so pcb is not an nonsense, but most of finished clones are, do to sub-par components.
2 - some pcb's are direct copies, so no difference. Finished clones in particular luck management boards. IFAIK chenese enthusiasts did not made copy of management board at all.
3 - original definitely exists I had experience of listening it at Toronto Audio Fest last year. Or you are asking something else?
RE. Black boards
I work in finance in IT, work situation still very intense do to the very rush project also I moved a month ago. So, after I log off I don't have any juice left in me to reach for the soldering iron or finish unpacking. Hopes are it get easier with it release mid June.
I had plans to the modded board (Caddock for 39R) and some other small changes, but luck of time spoils it so far.
Last edited:
The pcb on the left is from another amp altogether, perhaps from a LHC208 and the photo on the right is from a CTH8550
The Hungarian circuit is of course inspired from the video, but we cannot say much more about its credibility.
The distortion spectrum roughly matches the Stereophile test results, but not 100%.
Indeed, that resistor is very audible. I recently removed the entire CCS and put a depletion mosfet in its place. Initially a DN2540 and subsequently a IXTU01N100D. The DN2540 confirmed my previous impressions for lack of musicality but the IXTU01N100D is a clear improvement upon the 108 original CCS. Will let it go playing for a week before committing to making new boards.
Offset at the moment is less stable perhaps because the current setting resistors are low power and heat up.
A copy of the main board of the 1: 1 amplifier was made by the Chinese from the original amplifier - this is a fact of the guys (we are watching the Chinese forum), but they didn’t go further as the dartzel’s output control and protection scheme is tricky, and they went the easy way, but we’re with you we are not looking for easy ways. Basically, I think this amplifier has a powerful power supply, to which I paid attention and put Sprag, for my acoustics it is quite good, a 30 cm woofer walks. The garrbage board is an upgrade and possibly improvements, but version 2 seems completely different to me.
No offense, about these without comment, commercial projects. LHC-208 : the best of digital audio reproduction | darTZeel Audio SA CTH-8550 : a true revolution on integrated amplifiers | darTZeel Audio SA I wrote to a person on SER-8550, he said he wasted his money.
when I ask if the original exists (question that does not answer) I mean that the original SEEMS is absolutely identical to the Chinese clone or Chinese copy or whatever you want.
I add :
purchased the clone and powered by a 300 VA transformer and 2 BC of 22,000 micro per channel, I was unable to distinguish it from the original, and with the original I mean the final from € 38,000
yes, it looks complicated enough.
But for what reason?
The 108 scheme is full of cap, input and signal ground, so the control of the offset SHOULD be good and also the control of DC coming from upstream.
Overload protection?
Delivery limitation?
It does not seem.
Rather, I think a crate protection is missing, but I think so.
In any case, the 108 and everything in the final amp appears quite original and not immediately understandable, to put it politically correct
The original 108, which the clone circuit is based upon was 18k, the 38k one is the series 2, following an entirely different circuit, but is still sounds indistinguishable from the clone to you?
The original 108, which the clone circuit is based upon was 18k, the 38k one is the series 2, following an entirely different circuit, but is still sounds indistinguishable from the clone to you?
I post my impressions.
the clone, as I say, I consider it little distinguishable if not indistinguishable from the original despite having, the clone, a smaller power than the original.
I repeat, I am sure that the 108 scheme, as I know it, has no need for 132,000 micro and 1,000 VA per channel as power supply, at least from my tests and even just looking at the scheme, but I say it with utmost respect for the work of others of course
I always refer to the pattern I know, maybe what you call 18k or model 1, the one with only one pair of endings
to spanne the scheme of the 458 seems much more interesting and less critical.
Okay the open ring etc, but I have to make the speakers sound, don't invent who knows what and then find out that the new or presumed such invention (the principle is not the diamond?) Has big limits both in terms of stability and listening performance
Last edited:
the Dartzeel that I know, original, final power amplifier, model 108, 1 pair of power amplifiers, in Italy, share, list price, € 38,000.
Here is the list, that the list is crazy, I agree
Possible Ver2? Still missing a few caps, like the 6800uF/6.3V (possibly for the CCS 5.5V supply (simple Resistor+zener?), and the smaller 100uF (possibly bypass of the Supercap, as shown on the NF-458 schematic), but matched more or less the pcb image. Also input cap (large red wima possibly 10uF, like the NF-458 again...
Attachments
Last edited:
Funny enough, that's what i am doing atm too.
No idea where that 5.5v came from into Shany's circuit. If you want isolation from the CCS side, the logical way is to use a better CCS, not frivolous voltage regulation. The 6800 is very likely bypassing the zener.
I am nearly resolved to using a depletion mosfet for the CCS. It sounds better in my system but it may be because the 5W 39R wire resistor is missing.
No idea where that 5.5v came from into Shany's circuit. If you want isolation from the CCS side, the logical way is to use a better CCS, not frivolous voltage regulation. The 6800 is very likely bypassing the zener.
I am nearly resolved to using a depletion mosfet for the CCS. It sounds better in my system but it may be because the 5W 39R wire resistor is missing.