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Audio Discussions
Topic: Starting from scratch - new amps new system

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Posted by Dominic on 01-31-2007
I'm about to do what amounts to building a new system.
What i'd like to do is build/acquire a set of amps that can be hotrodded if-you-will in the vein of the melquiades re: channel tuning.
my goals from a technical/mech perspective are the following:
a not insubstantive amount of power, a solid power supply, loww humm, short signal path, long parts life, lots of adjustability ofr sound, minimal cost.
my goals from a musical perspective are:
discrimination in bass colours-and midrange too, deep depth of field (nowt to do w/soundstage), open but focused midrange, even distibution of dynamics - same amount of micro~, metzo~, and macro~ and have that hold true at all frequencies, overall harmonious sound.

My basic thought was that i'd get some cheap point to point amps with an elegant chassis that has tubes with many equivalents and some extra space for adjustment. something like the Antique Sound Lab wave 8 but el34 based for example. But i don't know. I really don't.
long term plan is to have three L-R-control (or six in the case of ob psu) amp boxes that are for all intents and purposes unified containing all correction circuitry, and integrate the speakers and source. Eventually with my own chassis design.
The question is, what rust bucket should i be looking for to hot rod. I have no idea how much money i'll be putting into this in the long run but the initial cost must be under 1k.


two notes:
- is there such thing as an off the shelf three box integrated?
- you might want to consider adding the abiliity to make drafts of posts
 Roman. dunno if the forum code will allow that though.


/have to sign off and get some sleep

Posted by Romy the Cat on 01-31-2007

Dominick I do not know what you asking and what you want to do but there is one area in your post that I would like to comment upon: the channel tuning in context of DSET.

The channel tuning is amazingly powerful tool, however it useful if all 3 conditions take place:

1) If it used properly.
2) If the installation has ability to use the channel tuning benefits.
3) If a person who responsible for the system sound has well-defined objectives

Generally a channel tuning could be viewed as THE ONLY proper equalizer available within entire playback. The secondary benefit is ability to tune the attach/decay dynamics and harmonic within a harrow bandwidth with respect to acoustics of the given room.  I would like to note that all those manipulation is imposable to make PROPERLY outside of DSET configuration.

The caT

Posted by Dominic on 01-31-2007
What i'm asking is for candidates that lend themselves to what i want to do.
Which is to find or build a pair of 'monoblocks' that can be successfuly modified into a potentially multi-channel tuneable amp.

Can you clarify what you mean by 'properly' regarding dset? That would be helpful i think.

Posted by Gregm on 02-01-2007
What I'm speculating is that you might opt for cheap -- non SET -- amplification for now, and get acquainted with the application of tuning channels... experimenting how this can operate within your environment. I.e. put emphasis on the concept and use the "gain" as a tool (and disregard the actual sonics but pay attention to the versatility this "topology" would offer). For example, the amplification modules from http://www.hypex.nl/ are quite affordable and acceptable (as far as this goes).

Of course, the electronic circuits are completely different using tubes... but, in the way of introduction it's, at least, cheap.

Posted by Romy the Cat on 02-01-2007

Gregm,

perhaps it is might be my incompetence in SS  but I do not see a whole a lot of ability to “tune channels” with SS. Sure it is passable to plays with crossover and volumes but it is possible to do at speaker level as well.  With SET however it is possible differently loading the output stages and by combination the drivers, loading and crossover it is doable to shape any imaginable sound. I do not think that it is possible with SS to change harmonic signature of the amp without masking changes in circuit, and presumed impact to something else. With SET it is easy - juts rearrange some sections in OPT transformer and you are in a business.

The caT

Posted by Dominic on 02-02-2007
I know there are millions of ways to implement a digital amp, but i have no idea how easy it is to switch from one implementation to another. Or whether they sound any different.

I got to thinking. Maybe a Bottlehead kit of some variety would satisfy the basic requirements of above?
Which might be most promising perhaps?

There are a couple heathkit models out there in the wild that go pretty cheap at least
might be useful for parts? I keep trying to do an amp for me
but i keep ending up not doing it.

Posted by Gregm on 02-02-2007

The hypex are ready-made on boards that take no playing around without major complications. Sorry & thanks.
(Btw, "tuning" is doable with ss -- but there's pain involved; by comparison, the versatility of tube is much higher)


Posted by Paul S on 02-02-2007
One of the most frustrating things in hi-fi, IMO, is using the wrong speakers for your room and/or the wrong speaker/amp pairing.  It is impossible to get anything right or to even get started if you don't get this right (enough).  For example, I have read posts from people who are "quite happy" with the "full range response" they get from 45 SETs driving big, heavy FR speakers in large-ish rooms, yet I remember how poorly this has worked in every example I ever heard.  My point is that you will get the most out of your project if you think through at least the actual, real world power requirements of your chosen speakers/room and then try to project whether you can still suffer the losses you will incur by dividing your output for "channels".  It has been my experience that just doing the math on an amp's rated power versus speaker efficiency is not enough, and this is as true of HE horns as it is with less efficient speakers.  In  any case, it certainly does not hurt to have some power "in the bank", plus some extra for "channels".

Actually, I assume that what I have said so far is not really news to you, but you do seem to be drifting toward a weak amp "just to get started".  I don't know about the Melquiades, but most SETs you could easily find and buy cheap have very little in the way of actual motive force.  In fact, even most of the big expensive "powerful" SETs you see out there probably would not be good candidates for dividing, since very few SETs approach full range under the best of conditions, and you would not really get the Melquiades' band-specific OPT benefits from just any old amp.

FWIW, I was going stir crazy just trying to find a pretty-much-full-range comercial amp to hook up conventionally to my 3-ways, 40 Hz - 20+ kHz.  Don't let anyone kid you, good FR amps don't grow on trees.  Despite initial appearances and/or imagined hassle/expense the Melquiades might actually be the fastest, easiest and cheapest route for you to take, at least by the time it's all said and done, if you insist on the arduous "dedicated" route.

Best regards,
Paul S

Posted by Dominic on 02-03-2007
The speakers i've got are JBL studio monitors using a 2420 (118dbwm 16O) on top and a 2231 (93dbwm, 8O) on the bottom, which already accomodate bi amping, though like i mentioned a midrange driver would probably be a good idea and so a six way amp would be nice. I'd also like to try bi-amping my jensen Coax drivers.

i suppose even though i've explained my reasons i haven't divulged my plan.
Now i realise it's a tall order.
I wouldn't mind 1.5kper 2-channels but it appears that i'd have to build 4 regular Melq. to get 4 channels. which would be around 6k us, which kinda sucks as a short term outlay for me, which isn't a big deal usually i'm very very patient, but i'm amplifier-less as of now; what i've got has kicked it and i need something to get me in on the ground floor, and i'm hoping this is the right building. This is exacerbated  by having some other big costs at the moment: dropping a trip to europe in favour of building an amplifier seems a funny trade-off.
I'm pretty sure my ultimate sonic goals are far removed from what i can afford as a completed product that answers those goals (off the shelf or not) so what i was getting at was something 'good-enough' with (or can be modified such that it has) at least four 'ways' that i can 'flavour' according to my transducer situation and eventually 'upgrade to full speed and dynamic ability' bit by bit as funds allow. Maybe cheap stereo 6c33c, using half a 6c per channel and then eventually upgrade to melq level? Something to tide me over for the meantime at least. I do have some parts for a gainclone project, but that doesn't seem to offer any useful place to go soundwise, and as we seem to have established, probably won't be all that great a channel tuning device.

I'm asking these questions because i don't have a Dimitri or Geoff to pester to help turn my dream sound into an actual machine. The closest i've got couldn't tell me the first thing about what makes an amp perform, only what procedure to follow when assembling.

Posted by Paul S on 02-03-2007
Big 93 dB woofers with a "split" no-feedback SET?

Perhaps if you re-think the LF drivers you might indeed start with a vanilla version/pair of the Melquiades, just to get a sense of what you're dealing with.  If you are able to get or get a sense of their best and it meets your requirements, then keep going.

Best regards,
Paul S

Posted by Romy the Cat on 02-03-2007

 Dominic wrote:
i haven't divulged my plan…

No, you did not do before and you are not doing it still. I think the problem with that you are expressing is that you have no desire to EXPLAIN FOR YOURSELF what you do.  Forgot about the amplifiers, speakers and the rest of the audio crap. So, far you kind off are shoveling the names and definition but it does not look that those definitions have a lot of realization for you at this point. I do not mean to be rude but I also would like to be honest and I do not feel that so far you’re looking for anything relevant. Save you money and save your time and pursuit for a time being different projects outside the audio domain. Better audio comes from our better understanding of the nature of our own requests in audio, not from abstractedly “better” amplifiers or abstractedly “better” speakers….

Confucius one said that it is the hardest thing of all is to find a black Cat in a dark room, especially if there is no Cat… I dod not think we humans have changed a lot since he said it 2500 yeas ago...

Rgs,
Romy the Cat
(No pun intended)

Posted by Dominic on 02-03-2007
The thing is i need something to use now that what i have isn't functioning. I'm not really asking at the best time, as i hadn't been thinking about the right questions for a while, and this is sort of an act of desperation to get my playback just back up on its feet.

Posted by Dominic on 02-05-2007
 Romy the Cat wrote:

No, you did not do before and you are not doing it still. I think the problem with that you are expressing is that you have no desire to EXPLAIN FOR YOURSELF what you do.  Forgot about the amplifiers, speakers and the rest of the audio crap. So, far you kind off are shoveling the names and definition but it does not look that those definitions have a lot of realization for you at this point. I do not mean to be rude but I also would like to be honest and I do not feel that so far you’re looking for anything relevant. Save you money and save your time and pursuit for a time being different projects outside the audio domain.


To more fully address this from my perspective.
I don't feel i'm in a real position at this point to be going directly after the more abstract goals in playback. I have some more experimenting to do to more fully understand some relationships. I am however, fairly certain of the way i want to go as far as overall system topology. That of a well designed horn system (which still seems like a moving target) with dedicated badwidth amps per channel that share a voice and accomodateWhat i want in terms of this topic is a flexible though simplified tool that will allow me to experiment with multi amping and hopefully channel tuning. I don't intend for my current speaker setup to be anything like the eventual solution ( outside of any upstream influence the speakers' textural substrate for the tonal perspective is all wrong, like printing a photo on the wrong kind of paper, despite using the right colour process, or something) I'm not sure why you don't get this point, but i won't worry too much abut it: i just want a tool that can grow with me, it doesn't have to be tremendously anything to start with as long as it serves as base that can be adjusted. I bought those above speakers as a tool. I've never had really solid LF capability nor strongly dynamic upper mid to work with, it's been a useful adventure. Which is not a bad cop, since vintage jbl stuff has a 1:1 resale value.
Within this context, i was thinking that one option (i was getting at this before) would be to build something simplified that works around the key parts of the melq so that i could at some point try the melq sound by modifying a bit. Another option would be to use something like the bottlehead for HF and a gainclone for LF, I stated this thread with the aim of finding other options and the usefull-ish suggestion i got was to go with a thouroughly but abstrusely documented single channel. While totally useful in its own way, especially from the all important sonic perspective, it falls down on a couple points: it's one channel, two, i basically need my hand held to build an amp; hence the bottlehead idea since the instructions are apparently very easy to follow and well documented. If it weren't for the fact that i'm loathe to rehabilitate my marantz gear i'd just as soon collect the parts for a 4-way melq setup over the next couple years and just listen to good music in the meantime. To reiterate; what i want to do right now is re-amp post haste without having to spend again in order to biamp or try 'dedicating', hopefully with something that hits some of those points in the first post, which was not an exhaustive list as i was writing that at well after 4 in the morning, blech. Perhaps there's no-one who can really find a solution for me, but it was worth a shot i figured. It's just so hard to find appropriate solutions to -in the context of the 'real world'- abstract opaque concerns. Hell it's hard enough just finding a compression driver in a 'hifi' speaker to listen to.
 There's still a bit more on this subject i'd like to hash out but my mindset at this hour isn't bearing further fruit on the topic.

Posted by Gregm on 02-06-2007
If it weren't for the fact that i'm loathe to rehabilitate my marantz gear i'd just as soon collect the parts for a 4-way melq setup over the next couple years and just listen to good music in the meantime. To reiterate; what i want to do right now is re-amp post haste
Buy a vintage -- amp, or "good" receiver (i.e. one that has an acceptable tuner section in it) for now?

Posted by Dominic on 02-06-2007
845 integrated

Aside from not being sure of the desription, it could have something going for it in context?
No interior pics but he's got another one that's 845 monoblocks for a bit more money, looks really nicely done inside.

Posted by Dominic on 05-02-2007
i had browser issues again so some of the eloquence of my intended post will likely be lost.

anyhoo.

Maybe it's just me, but i'm almost never content with replacing what i've got with something equivalent. This would be as regards Greg's last post above.

I'm liking lately the idea of getting a chinese 845 based SET off ebay. Point to point(less fiddly modification), there's a choke coupled one available now, umm, 10 or so watts for under a thousand dollars, you know that sort of thing. What i'm still trying to figure out is whether or not there is a better way to do the same thing.

I wonder if i might be happy with how it (can)sound(s)?

Posted by Gregm on 05-02-2007
 Dominic wrote:
I'm liking lately the idea of getting a chinese 845 based SET off ebay. Point to point(less fiddly modification), there's a choke coupled one available now, umm, 10 or so watts for under a thousand dollars, you know that sort of thing. What i'm still trying to figure out is whether or not there is a better way to do the same thing.
I wonder if i might be happy with how it (can)sound(s)?
Dominic, as you yourself note, it's very much an answerless questionSmile
I understand you want to get active right now rather than spend time refining your thoughts, etc. You know, like in the Olympics, "participation is more important than winning".

But, IMO, what you need to decide right now is on a spkr-amp application. Otherwise it's a journey without an end -- end being both the "objective" and the "completion".
For example, Romy has horns & boxes and distributed amplification in a well-defined, specific, and reproducible application.
In yr case, is it the JBL that's going to play and if so, with how many  channels/side, and how...?
Or is it passe-par-tout amplification you wish to start with, and look for a speaker later (but how can you do that if you don't know some, at least, of the final characteristics of the speaker?). You understand my drift.

If you still wish to embark on a journey and see where it leads you, buying a ready product and playing with it is indeed an option (and the one you mention gives you 6channels for $3k). The other alternative is to assemble s/thing by y/self from scratch... but in both cases, you'll need to have some indication of the end of the journey!
 
And remember: proceeding like this, success will be fortuitous rather than by design, no?
Cheers

Posted by Dominic on 05-04-2007
ya i got your drift. if i can trust my initial reaction(in terms of how to articulate my idea) then my objective is a sound/performance i have in my head. I don't really expect completion but i do expect the periods of "good enough" to get longer as i get closer. For the mean time the idea is to have a basis.
I want the amp to serve as an interim solution, a tool hear new things, to find out what i want down the line, and how to get certain things out of a circuit. The speakers are likewise, i bought them as a learning experience. What i'd like is to experiment.
Once i've gotten what i can out of the speakers i can embark on that voyage having further expanded my experience while having got a better idea of how an amp fits into that.

i'd like to take the buddhist route through this whole thing but i'm not sure what that is yet.

it would be the jbl stuff for the mean time, the configuration therof is likely to change though.

Posted by Dominic on 05-04-2007
to be clear:
i do have some expectation that 'my final solution' will consist of dedicated amplification per driver in a substantially horn loaded arrangement. I have some expectation that amplification will be single ended and quite likely have a battery contingent as one day i expect to live off the grid. but a lot of that is flying kites.
What i do know for sure is that i'll always want to play vinyl. which is of course neither here nor there.

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