Power amp recommendations for 1000 and under


Hello all

I have budgeted $1000 dollars for a power amp (new or used) and wanted to know from people what they would buy in my position.

Thanks
krazeeyka3ab
Krazeeyk: I "passed judgment" on your end goals by looking at the equipment that you mentioned as being on your list of things to check out. If you look at them individually, you might better understand why i said what i did.

Rega Planet: This player is typically known for being on the warm and smooth side, some even call it "dark". While any / all of those comments MIGHT apply, it would depend on what you were comparing the Planet to and your particular likes and dislikes. Having said that, i don't think that anyone that has ever heard a Planet would consider it to be bright and / or etched sounding.

Adcom gfp-750 pre-amp: Can be used in either passive or active mode. Most line sections when run in passive mode are typically on the warm and smooth side. That is, unless you run into impedance loading problems. Given that the Adcom can be switched into active mode with a transistor gain stage, it is actually a "dual personality" unit. When going active, this piece is more agressive sounding with added treble brilliance and a more pronounced or "forward" upper midrange. This gives you the opportunity to somewhat alter tonal balance without having tone controls. Just make sure that you compensate for the differences in gain when flipping from passive to active : )

Vandy's: In general, Vandy's are considered to be "warm and smooth" sounding rather than bright and etched sounding. Many people think of Vandy's as "sugar coating" the sound i.e. they are not overly revealing and tend to hide flaws due to what some would consider a lack of high frequency output. Personally, i think that Vandy's ARE on the warm and smooth side. BUT, i also think that they are fully capable of showing the difference in components / system changes IF properly set-up. They are a little more room placement sensitive than some other speakers and can tend to sound "tubby" or somewhat "bloated" if one is not careful. I would not situate Vandy's anywhere near a room boundary ( rear wall, corner, etc... ) if you wanted to maintain a relatively even tonal balance.

So, as you can see, the majority of gear that you listed is known for being "smooth" sounding rather than "etched" or "extremely revealing". As such, one could end up with a system that was a bit "too warm" if you weren't careful i.e. lacking in brilliance and / or "open-ness". The Adcom active / passive unit would allow a bit of tonal flexibility in this respect while keeping the system simple without the need for "gadgets" ( tone controls, equalizers, etc... ). As such, the selection of amp & cables used in such a system could be a bit of a make it or break it point.

With that in mind, i don't know what you've been reading, but i don't think that you've done a bad job at all of selecting gear, especially if you have just walked into this "hobby".

As to being able to understand many of the terms that you have / will read about here, try this link. It is a shortcut to J. Gordon Holt's Audio terminology. Just bare in mind that some people can use the same term and still have a different understanding of that term or be trying to make a slightly different point.

Unsound: I have owned the Forte' 1A, 3, 4, 6 and 6A. The 1 and 3 sound somewhat similar and the 4 and 6 sound somewhat similar. The 1 and 4 are "Class A" and the 3 and 6 are AB versions. All of these amps run quite warm and should be powered up 24 hrs a day if looking for optimum sonics.

One could consider the 4 as being a newer version of the 1 and the same can be said for the 6 being the "replacement" for the 3. In my opinion, the 1 & 3 are slightly leaner sounding than either the 4 or 6. I also think that the 1 & 3 have a little bit more "air" but can be somewhat lacking in "punch" due to the lack of bass "weight". The 4 & 6 both sound fuller but are not quite as "airy" or "sweet" sounding. Personally, i think that the 3 is the "sweetest & airiest" of the bunch. All of them will drive low impedance, low sensitivity loads but may not do so with the most authority. I base this comment on the fact that i have used all of these amps on speakers that are 82 - 83 db's "efficient" ( HA, is that a contradiction of terms or what ?!?! ) and measure 2 - 3 ohms over most of their range. I have used other amps rated for similar or greater power output and not been able to achieve the same sound pressure levels with as much ease or clarity.

As you probably know, the Forte's started out as the "budget" product line of Nelson Pass' Threshold. As such, the first thing to go in any "budget" power amp is the power supply. A smaller transformer with less filter capacitance is the typical result of "cost cutting". Hence my comments about being able to drive low impedance loads, but not in the same fashion as some of the other products that came out of the same manufacturer.

As to why some reviewers and "audio laypersons" might have had less than stellar or very different results with these amps, the reason is quite simple. The amps are "chameleons" and change sonic characteristics as the load changes. As load impedance, inductance, capacitance, etc... is varied, so will the tonal balance of the amp. Don't ask me why this is so, but it has been documented in more than a few earlier Threshold designs. As such, one could change speaker cables and not only hear a difference due to the cables, they would also hear the amp change due to the variance in the total load that the amp sees. If this sounds "confusing", i guess it could be. An amp that sounds "lean and slightly bright" could come across as "bloated and dull" in another system due to the various loads presented to the amp.

Some will say that this is "crazy" as it throws a major variable into the equation, but i've not had a problem with it ever. Then again, i have a lot of different equipment, cabling and speakers at my disposal to try and make things work. The other side of that is that i have not run into a situation where i was NOT pleased with the outcome so long as "some" attention was paid to how things were set-up. I have used a Forte' 3 as a "loaner" amp to some of my friends a few times and they have all REALLY liked it. All of the comments have been something to the effect of "VERY sweet sounding, delicate and airy but lacking bottom end". As such, i agree whole-heartedly. Given the amount of apparent "warmth" that Krazeeyk had built into the system he was looking to build, i thought that a slightly lean yet very open and delicate sounding amp would work very well.

With all of the above in mind, one can REALLY hear a big difference with speaker cables when using one of these amps. However, one can't put all the sonic "differences" on the cables alone and would have to realize that the amp was also partially responsible for what one was hearing / recognizing as "different". So long as one can find a suitable "total load" ( speakers and cables ) that these amps "like", they are capable of very good sonics for pennies on the dollar. With some simple upgrades as mentioned above ( increased power supply reserve, upgraded rectifiers, etc... ), one can have a VERY nice sounding amp that competes with current designs costing hundreds if not thousands of dollars more. Sean
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PS... The 4 and 6 make use of IGBT output devices that are no longer in production. One can find a source for these should something ever go wrong with the amp though.

PPS... Another friend of mine lives out of State ( Ohio ). He ran across a good deal on a Forte' 6, so he picked it up for me to keep as a spare. He ended up hooking the amp up and running it on his big Acoustat's. As you know, Acoustat's are not easy loads to drive. He ended up liking the amp so much that he kept it, which was fine with me. In fact, i was glad that he did so as i had been trying to push him in that direction for quite some time. For sake of comparison, he had been running and still owns two different NYAL Moscode 600's ( one modified, one stock ), a modified Hafler DH-500, a custom built amp made by John Hillig of Musical Concepts, a Robertson 6010 ( which i ended up with ), etc...
Sean, thank you very much for your thorough post. I'm surprised that Threshold products in particular would be so sensitive to thier given load(?). I now have more rather than less to ponder as I didn't realize these products were so system dependent. Am I correct in my assumption that they are a bit more dependant than most others? BTW, while I agree with you that the Rega Planet is on the dark side, I seem to hear (it has been a while) a small band of bightness with this player that can be some what irritating. This is not meant to be a knock on this superb value player.
Sean, any thoughts on the Coda amps? There seems to be a Threshold connection here aw well.
Unsound: I am not familiar with Coda products other than knowing that some former Threshold employees now work there. I have wanted to check out some of their power amps, just never had the opportunity to.

As to some of the Threshold products being "somewhat unstable" or changing sound with different loads, Moncrieff mentions this in some of his reviews but states that he basically likes the sonics of them when well matched. He is one of the few reviewers that actually checks for "load imperturbability" ( boy, is that a mouthful !!! ). John Atkinson has also mentioned this to some extent, even going so far as to say that some amps change tonal balance as the volume is altered ( Rotel ). I think that many amps / preamps are somewhat sensitive in this area and that is why cable selection is so system dependent. Sean
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I bought a Legacy 4/3/2 (manufactured by Coda) for under $1k. I use it in 2 channel mode which operates in class A mode up to about 25 wpc then gracefully transitions to class A/B up to 450 wpc into 4 ohms. It sounds as good as anything I've ever heard. The class A mode provides low distortion and wonderful detail at low volume while the 450 watts frees the sound from the speakers. Nothing seems to come directly from my speakers (Infinity Prelude MTS) unless the source was recorded that way. I've experimented with the 4 channel mode which provides 225 wpc into 4 ohms and you can definitely tell the difference, even at moderate levels. Power is good.