thebes Posted June 10, 2004 Share Posted June 10, 2004 I keep reading about monoblocks and seeing pictures of them in 2 Channel but have little concept of what they actually are and what they do. I presume they are two dedicated amps that send seperate signals one to each speaker. If so, how does each of them get the signal to to each speaker at the exact same time. Is some sort of preamp needed? How can they stay in phase with the slight variences two seperate mechanical devices must produce? Why do people like them over an integrated amp? See what I mean. Total newbie in this area and need some basic instruction not for a purchase but just to educate myself. Quote Link to comment Share on other sites More sharing options...
dbflash Posted June 10, 2004 Share Posted June 10, 2004 You are correct in your basic understanding. It works kinda like this. A receiver has both a preamp (selects what you listen to and volume control) and amps which send power to your speakers and usually a tuner to listen to the radio. This is all contained in the same unit. An integrated amp has two amps, one for your right speaker and one amp for your left speaker in the same unit. You would need a separate preamp for the above functions to work. The integrated amp is attached to your preamp using interconnect cables (IC). Monoblocks are separate amps. One for each speaker. They are attached to your preamp again using IC. On the back of your preamp you have RCA connectors. To keep this simple you will have a set of inputs for your CD player. You also will have a set of output RCAs. One end of your interconnect goes to the output of your preamp and the other end goes to the input of your monoblock. If your CD player has a volume control you could come straight out of your CD player again into the monoblock input. Hope this helps. Danny Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted June 10, 2004 Share Posted June 10, 2004 Thebes, seperate monoblocs also can provide some advantages. They are essentially immune to crosstalk, as there is no shared wiring or physical spacing. Each channel will have a dedicated power transformer, so a musical peak in one channel will not be robbing power from the other channel by depleting the shared power transformer of good power. A stereo amplifier, like the Dynaco ST70, will have one power transformer and two output transformers. The monoblocs will each have one power and one output transformer. Rather than the stereo patch cords going from the preamp main outputs to the amp stereo inputs, you will have seperate single patch cords going from the preamp main outs to the single monobloc amp input on each amp. Plus if you are ever involved in a tube amp tossing contest, it is much easier working with monoblocks than a stereo amp Quote Link to comment Share on other sites More sharing options...
thebes Posted June 10, 2004 Author Share Posted June 10, 2004 Ok thanks I get it so far. You must have a pre, not direct cd to monos. However, I still see a lot of room for mischief in signal transference. For example, my Scott 299 has bias controls to I presume provide allowances for the varience in the different tubes and output transformers. With two physically seperate amps how do you keep them in phase? And what's all this tuff about set/push/pull/triode are these just different ways of doing the same thing? I know it sounds a little dorky but every time I see a picture of these things I reminded of some sort of simplified Rube Goldberg machine invented by Jules Verne. You know, sort of Victorian looking. Still scrathing my head. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 11, 2004 Share Posted June 11, 2004 Yes, generally one would have a preamp in addition to the source. Depending on the nature of the beast, some power amps can be driven directly from the CD, using the CD remote for volume control. Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted June 11, 2004 Share Posted June 11, 2004 "Yes, generally one would have a preamp in addition to the source. Depending on the nature of the beast, some power amps can be driven directly from the CD, using the CD remote for volume control." In addition, if the amplifiers have gain controls, one can use those for volume. I did this in my initial 2 channel rig - just CD, amp, and speakers, since my amps had gain controls. It's a nice way to ease into a good 2 channel rig, if the amplifiers you choose happen to have these controls, since you can do without a pre until you decide what you want/can afford the pre, etc. Quote Link to comment Share on other sites More sharing options...
JohnA Posted June 11, 2004 Share Posted June 11, 2004 Monoblocs are easy. They are just single channel stand-alone power amps, as opposed to 2, 3, 5 or 7 channel power amps. All power amps require some sort of preamp for switching and volume control. Generally, the seperate power supply and high quality components in a monobloc mean it will sound better than other configurations. This especially applies in demanding situations for the power supply. Quote Link to comment Share on other sites More sharing options...
space_cowboy Posted June 12, 2004 Share Posted June 12, 2004 I have the Wave 8 monoblocs, each feeding a LaScala. Another ASL preamp drives the whole lot. Enjoy... Quote Link to comment Share on other sites More sharing options...
NOSValves Posted June 13, 2004 Share Posted June 13, 2004 People move on from the integrated and stereo power amp setups when they decide to dive after that last 10% of the available sound quality. When there going from Stereo power amps to mono blocks I would say there going after the last 5%. The problem with the last 10% is it cost thousands more then what they had. They have to decide if its worth it to them. To this day when I get done rebuilding a great integrated amp and fire it up I look up at my $4000 worth of separates and wonder how I ever let myself get sucked into this but somehow there is just no turning back Trust me they are not 8 times better by any stretch of the imagination. The true value in audio still lies in used integrated amps even though the cost have risen by a huge amount. Craig Quote Link to comment Share on other sites More sharing options...
garymd Posted June 13, 2004 Share Posted June 13, 2004 ---------------- On 6/10/2004 5:47:10 PM dbflash wrote: An integrated amp has two amps, one for your right speaker and one amp for your left speaker in the same unit. You would need a separate preamp for the above functions to work. The integrated amp is attached to your preamp using interconnect cables (IC). ---------------- Danny, I think you meant Stereo Amp instead of Integrated Amp. An integrated amp includes the preamp. It's an amp/preamp combo, ie., integrated. Your basic integrated amp includes 2 amps and 1 preamp in the same unit. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted June 13, 2004 Share Posted June 13, 2004 And to throw more fuel into the fire...most (but not all) stereo 2-channel amps can also be converted into a single mono power amp by way of a switch or by a "Y" connector to one of the amp's RCA connectors and a single interconnect used for the preamp's output. Of course you'd need two identicle stereo amps bridged into two single mono amps to power each loudspeaker...see one of my brother's system last year using two stereo McIntosh MC250 power amps bridged into two seperate mono amps, each driving their own loudspeaker. Quote Link to comment Share on other sites More sharing options...
thebes Posted June 14, 2004 Author Share Posted June 14, 2004 Ok. I think I've got everything so far. But with two seperate amps how do you adjust for what must be slight differences between the outputs fromt the amps. I mean the two monos cann'y be exactly the same physically and/or the output tubes may wear at different rates. Is this accounted for by simply tweaking the pre? I mean I wondering how they are kept in phase, I guess would be the right term. Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted June 14, 2004 Share Posted June 14, 2004 Thebes, normally the left and right channels will have some shared and some different information. If the musical info sent to each channel was the same, then you would be looking at a mono recording. If you take into account time differences during the transfer through the patch cords, you could have a millisecond difference in travel time from your CD player or TT to each speaker. There are zeolats that swear EVERY cord and speaker wire length must be identical to ensure identical resistance and uniform time transfer. Some are the same people who raise their speaker wires off the floor, something I only do when I'm vacuuming. I've noticed the stereo sounds like SXXX when I did this, proving that tech tweak to be totally false! Quote Link to comment Share on other sites More sharing options...
pablum Posted June 14, 2004 Share Posted June 14, 2004 Monoblocks have no inherent advantage? Not in my experience. Dont always believe everything in here even if stated with cool authority. I will agree that stereo amplifiers can sound very good but I have also preferred monoblocks with certain designs. It's not the "fashion" statement either just like tubes on top. They are distinct reasons for this including individual power supplies and filtration dedicated to each amplifier/channel. Do some more reading outside this forum. You CAN have everything in one box but more often than not it ends up sharing one power transformer. But having monoblocks does not guarantee a great amp but claiming it's nothing but a fashion statement is not on the mark either, in my opinion. Quote Link to comment Share on other sites More sharing options...
Parrot Posted June 14, 2004 Share Posted June 14, 2004 Pablum, what are your thoughts on the EICO HF-81, the Rega Planet, Moondogs, Wrights, and Cornwalls? Quote Link to comment Share on other sites More sharing options...
edster00 Posted June 14, 2004 Share Posted June 14, 2004 None of them are monoblocks? EDIT: except the Moondogs and Wrights of course...my bad. Quote Link to comment Share on other sites More sharing options...
Parrot Posted June 14, 2004 Share Posted June 14, 2004 Shhhh. Edster, I'm trying to trick Pablum into admitting who he is. Don't give the ruse away. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted June 14, 2004 Share Posted June 14, 2004 "That fashion should not be confused with good circuit design which doesn't care about stuff like that. Some mono blocks are really good amps, so are some stereo blocs." mdeneen Slam dunk! I agree 1000% (but % means per 100, right? who cares, I agree 1000% anyway...) Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted June 14, 2004 Share Posted June 14, 2004 ---------------- On 6/14/2004 6:50:23 PM mdeneen wrote: BTW, there is no "inherant" advantage in mono blocks over a stereo amp. Anything and everything you can do with two mono amps can be done with one stereo amp. The fact that designers don't always CHOOSE to do these things in a stereo amp, doesn't change the fact that it's just two circuits. They can sit atop one hunk of metal, or two just as easily. (Believe me, there are some "crappy" mono blocks too.) Mono blocks vs. stereo amps are a bit like skirt hems. Fashion, more than anything else. We are currently basking in a very retro-audio period - exposed tubes, point-to-point wiring, mono blocks, wooden knobs, octal bases, and so on. That fashion should not be confused with good circuit design which doesn't care about stuff like that. Some mono blocks are really good amps, so are some stereo blocs. mdeneen ---------------- Aren't you trying to paint a superb Tom Kincaide like "no nonsense" painting with a 3 inches brush here? Ok for point-to-point being more a fashion than any sort of advantage, Ok for C37 treated wood knobs carved from carefully selected american birch (cut with a silver axe on a full moon night) for being totally idiotic, But: Maybe exposed tubes are more a matter of prefered aesthetics (and maybe better natural cooling without having to use a cooling fan somewhere along the road) Maybe octal base are a question of what the designer though was the better tubes for his idea. I don't think Craig used KT88s because they are octal based. If an idiophile is stupid enough to disregard an amp design because it use a 9 pin driver tube, well it's his loss. Maybe there is an advantage for having two distinct PSU in the case of monoblocks over a shared PSU in the case of a typical stereo amp. Notice that I'll exclude on purpose a stereo amp with a dual PSU or split rail PSU as those are extremely rare (and really heavy in the case of a dual PSU stereo amp). I somewhat understand the point you are trying to make but I think you should use a finer brush. I totally agree that there are poor monoblocks, poor stereo, poor SET, poor PP, poor phono, etc. But I wouldn't go as far as saying there is no inherant advantage to monoblocks (again assuming you are not using dual PSU in a stereo amp). Quote Link to comment Share on other sites More sharing options...
Lurch Posted June 14, 2004 Share Posted June 14, 2004 ---------------- On 6/14/2004 4:38:18 PM thebes wrote: But with two seperate amps how do you adjust for what must be slight differences between the outputs fromt the amps. I mean the two monos cann'y be exactly the same physically and/or the output tubes may wear at different rates. Is this accounted for by simply tweaking the pre? I mean I wondering how they are kept in phase, I guess would be the right term. ---------------- Actually, just about every stereo amp worth mentioning will have separate boards for each channels' output stage. So, they too will suffer from channel imbalances just as much as a monoblock. Phase shouldn't be an issue as the signal passes thru an essentially identical circuit in each amp. If I had a choice between two amps, of similar design, I'd take the monos every time. Jeff Quote Link to comment Share on other sites More sharing options...
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