I would concur with the above as i have found 2 mono amps to be better sounding than a single chassis dual mono etc ...
I'm sure you could repair your ML for far less than 2000 ...
😀 ....................................................
I would have to disagree about the mono aspect . I would wager a mono bloc version would be better sounding ...
Unless the design is inductor loaded or the like, x-talk is very limited, and counting out x-talk, I would be hard pressed to come up with a reason to agree with you.
As stated above, weight is the only reason for a regular power amp to be mono-blocks.
I have personally set the weight limit to 70-80 kg. Above that, it's getting too much trouble to move the amp around.
Magura 🙂
I think it's pretty remarkable that a big company like
Harmon would not repair the 23.5.
In any case, if your budget is constrained you are stuck
with either the used market or building your own. Since
this is DIYAudio, I recommend the latter.
😎
Harmon would not repair the 23.5.
In any case, if your budget is constrained you are stuck
with either the used market or building your own. Since
this is DIYAudio, I recommend the latter.
😎
I agree, Shame on Mark Levinson for not being able to repair their own amplifiers, they have two private contractors in the United States who they refer you for repair, both these repair guys charge a fortune knowing that you are stuck. I returned the amp to the buyer on ebay and got my money back. I will not buy a Levinson product till they get their act together, Harman Kardon ruined a good company. I am going to try and get a X-150.5 since this is more in my budget. from what I read it looks very promising.
NP: "I think it's pretty remarkable that a big company like Harmon would not repair the 23.5."
Trance: "Shame on Mark Levinson for not being able to repair their own amplifiers" -
the reason is easy the uneconomical for oneself and perhaps follow:
It is very hard, to disass'y certain Mark Lenvinson power amp devices for service and maintenance (through nessecary to solder out all power devices even for little works at the PCB). I have repair some "No 23" some years ago and I hate this work.
Additional to the normal repair work I had to cut out a section of a overheated board aera (ref current resistors for idle current of VAS) and must perform larger resistor components from this area (to avoid hot spot one more) and must additional perform free wiring of this devices.
Some capacitors arround this aera must be also replace through 125 degree versions.
For the customer who was actually an insult by Mark Levinson, at such prices, such weaknesses and deficiencies not to remooooove already while developing.
But we must not forget one thing: There are two groups of buyers: one, which is about the real (i. e. perfect sonic transmission), and one which is about their own status symbol (similar often like car's).
In the latter case - money save isn't important, and this user's don't like therefore any repairs; they prefer more to buy new products but more expensive devices as before (look at the successor collection from ML).
Latter group are the audience of Mark Levinson - I would say.
and therefore they don't see this unsatisfy. They say "nothing lasts forever".
Last edited:
I had ML stuff in the early 90's before Harmon , there CS was beyond approach .... sad to hear they have become such ...
Magura ,
I would say you have never done the Monobloc thing , give it a try , or even better move the power supply away from the flat amp ...
Magura ,
I would say you have never done the Monobloc thing , give it a try , or even better move the power supply away from the flat amp ...
Last edited:
OK, so i guess he is saying there is no difference between "his" stereo amps and his mono blocs , besides weight ? .... 😕
My listening experiences have been the opposite, especially when the transformer is moved away from the flat-amp board and inputs ...
Magura would love to see your approach !
we are talking rubbish here ;
there are too much possible variables and important things involved , so saying that monoblocks are ALWAYS better than any other concept is same as saying that blue chicks are ALWAYS better than dark chicks ;
without considering class of operation , amount of capacitance , size of xformer(s) , wiring quality blahblah , that's just teeth sharpening ........ so we can't make universal conclusion .
in any case - give me Papa's amp over ML ones , every day .
take that this way - Nelson doesn't need all that drek ( tightly packed monstrousity with preputium class of components) to make good amp .
what you pay is what you get .
in case that you need Nelson's monoblock - buy two smaller stereo ones and bridge them .
then you'll see those "fancier" monoblocks running to woods , trying to hide .
so - everything is in 3 things :
1.good & knowledgeable engineering
2.honesty
3.good pair of ears attached to reasonably sane head
first two are conditio sine qua non for manufacturer , last one for buyer
there are too much possible variables and important things involved , so saying that monoblocks are ALWAYS better than any other concept is same as saying that blue chicks are ALWAYS better than dark chicks ;
without considering class of operation , amount of capacitance , size of xformer(s) , wiring quality blahblah , that's just teeth sharpening ........ so we can't make universal conclusion .
in any case - give me Papa's amp over ML ones , every day .
take that this way - Nelson doesn't need all that drek ( tightly packed monstrousity with preputium class of components) to make good amp .
what you pay is what you get .
in case that you need Nelson's monoblock - buy two smaller stereo ones and bridge them .
then you'll see those "fancier" monoblocks running to woods , trying to hide .
so - everything is in 3 things :
1.good & knowledgeable engineering
2.honesty
3.good pair of ears attached to reasonably sane head
first two are conditio sine qua non for manufacturer , last one for buyer
Trance,
Check out this paper at passdiy http://www.passdiy.com/pdf/articles/powersupply.pdf
This should get you a much better idea of Nelson's ideas on power supplies.
Doug
Check out this paper at passdiy http://www.passdiy.com/pdf/articles/powersupply.pdf
This should get you a much better idea of Nelson's ideas on power supplies.
Doug
To have the transformer moved away from the amp board and inputs, is a design issue, not mono VS. stereo.
As Choky pointed out, there are many other variables, but for a class A amp, with reasonably constant current draw, the difference in real life, is a point of diminishing returns. I have actually made one amp in both mono-block and stereo version (SE class A), and it made no difference, besides when I had to move it.
You can see some of my stuff at Class-a-labs.com
The rest I'm hiding for non-Serbians 😉
Magura 🙂
Last edited:
Magura , i have to admit , dat is the first Clingon amplifier i have ever seen................... 😀
kan lyden guderne være med dig....
kan lyden guderne være med dig....
Last edited:
Did we get any good answer from Mr. Pass about mono block vs. stereo?
One thing I like about Nelson is that he encourages people to use their brains whenever possible. I'm guessing he'd probably rather not answer that question since it's probably too easy to answer yourself if you put your mind to it...
It's not some big, mysterious design voodoo. All other things being equal, does a dual mono/monobloc sound better? Yes... but the power supplies would make the amp far too heavy and, more importantly, the pricetag would make your wallet far too light. The Pass Labs amps are commercial products and have to be price/performance competitive with other manufacturers.
The vast majority of costs for building Class A amplifiers are the enclosures and the power supplies. The actual amplifier circuits are, comparitively speaking, downright cheap. If he were to start going dual mono/monobloc on his production designs they'd have to be in a totally different price range - one that most people simply can't afford.
He's doing the audio community two HUGE favors. He's offering world-class production units in a price range that makes them obtainable by people of fairly modest means. On top of that, he freely shares many of his designs including support FREE of charge here on diyaudio so that we can build things we otherwise couldn't afford from a production unit - such as monobloc amps.
Pass does do dual mono on production models, just not the amplifier in question here. This amplifier dissipates roughly 350W at idle. The style in which he builds amps dictates that this design can easily be put into one chassis, and everything is kept nice and cool...relatively speaking. His philosophy for class A operation means that the PS is at least 3X over-rated, the PS will never run out of juice (20 amps). Couple all that with world class engineering in circuit design, and cross-talk between channels is probably close to immeasurable. I've built both styles, using the same exact circuit; dual mono supply, and then sharing the same supply, and could simply not hear a difference. If you have proper supply and circuit engineering, going dual mono is ONLY necessary due to weight and size. If you have a crap design, wimpy power supply etc...then going dual mono would be the way. Its a placebo effect...."my amp is dual mono dude, its has to perform better, certainly better than your one box stereo version"....rubbish. If the design warranted dual mono layout, then I'm sure Nelson would have gone that way. Maybe he could chime in.....
Last edited:
Pass Labs make XA60.5, XA100.5, XA160.5, and XA200.5.
He also makes X260.5, X600.5, and X1000.5
These are all mono blocks.
Pass Labs: Products:
If I had the money, and was single, I would buy myself some XA60.5 mono blocks.
He also makes X260.5, X600.5, and X1000.5
These are all mono blocks.
Pass Labs: Products:
If I had the money, and was single, I would buy myself some XA60.5 mono blocks.
Last edited:
Hello Magura,
Nice work! I'm considering using chokes in my F5 build but is a little put off on the prices for the chokes. I think the Hammond chokes go for about $30 each. Diy chokes could be an option. Mind sharing the recipe for your chokes? What are the dimension of your chokes, wire gauge, etc...?
Thanks,
David
nope ;
that is amp of one Serbian DiYA member ;
he's not skilled in DIY , so I participated in project ;
he purchased and paid for all parts (I told him what and where) - box from HiFi200 , xformers , caps from GB , PSU pcbs from GB , additional front plate from local box guru ( AKA Leonardo on our forum) , where logo is result of collective fun ;
inside work is mine , along with Babelfish pcbs and related small parts
Attachments
- Status
- Not open for further replies.