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Adcom GFA 5300 output

asilker

asilker

Super Member
Just bought a gfa 5300 but haven't been able to plug it in and get it going.

Anyway, regarding Adcom, I hear all over the place comments like "no slouch", "rated conservatively", "these have beef!", etc. Generally well respected brand known for having a few ponies under the hood.

Yesterday I read an interesting review on the 5300. Keep in mind, official literature for this amp claim 80wpc @ 8ohms mosfet design.
d6d298e3f3d21b59df120e698b743afa.jpg

This fella claims his buddy tested the amp at a whopping 120wpc @ 8ohms. That's quite a bit past 80wpc!

Has anyone else noticed this in Adcom power amps? Could this discovery be for real?
 
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So? You think our ears are any better than yours? So why not give us your impression and intended speakers etc. :D when hooked up.
 
Binkman said:
So? You think our ears are any better than yours? So why not give us your impression and intended speakers etc. :D when hooked up.
Click to expand...


Thanks for the encouragement! I have to pick the amp up from my cousin in a couple weeks, so I still don't have it yet. I'll definitely update when I can hear it tho. My speakers are Infinity Reference Five's with graphite mid and bass and the circular emit tweeter.

I'm just wondering if anyone has tested this amp and gotten similar readings, technically speaking
 
The Adcom ratings factor in the %THD which is a major component of the calculation. It may bench test far above the rated power but the distortion is above their accepted limits at that point. All that being said I am very fond of the Adcom two channel line and I've been using their amps in my main system for many years without a glitch. I've got a GFA-535 II as well as a 555-PRO and a GFA-2, they are fine amps indeed IMO.
 
Oh duh. I always forget that these things are all in relation to each other.

I heard a 545 ii and that's what got me interested in the brand. To my ears much better control and sharpness than my NAD's
 
There's a magazine review of the GFA-535 mkI that points this out,in the review they talk about how that the small Adcom actually puts out closer to 100wpc than it did the rated 60wpc (IIRC it was like 80wpc),but as was mentioned here the way they (Adcom) rates their amps makes them appear to be rated "conservatively" be it intentional or not.

The reviewer pondered if that was possibly due to the fact that the GFA-545 was rated @ 100wpc and they (Adcom) did'nt want the smaller "upstart" GFA-535 amp encroaching on the bigger GFA-545 amp's potential buyers,but by various accounts the GFA-545 is said to be under-rated as well.

Also consider that the 200wpc @ 8 ohms GFA-555 jumps up to 325wpc @ 4 ohms,and when you bridge the 200wpc GFA-555 the power jumps up to something like 600wpc @ 8 ohms,and it's commonly held that most GFA-555's check in above their 200wpc spec as well.

I believe that is often refered to as the amp's headroom and/or overhead,ie: available dynamic wpc above/beyond the "rated" wpc specs,but dont quote me on this one.

What I do know is that I like the Adcom stuff for the most part,when buying used gear it suits my budget that's for sure,currently I have GFA- 535/545/555 (all mkI) and a GFA-5200 mosfet.

They dont always get "mad props" on these audio forums though.

Kinda like the Rodney Dangerfield of amps "huh,,,I dont get no respect..." LOL.

FWIW

Bret P.
 
Bret, coming through fast with that article. Thanks

I know it's been asked before, but any comments between the bipolar and mosfet designs?
 
It's a subtle difference,complicated by the fact that they are being used in very different systems and very different rooms.

The GFA-535 is being used in my BR with a Adcom GTP-450 preamp/tuner and using a Rotel RE-1010 EQ in the processor loop and played thru some Sony SS-B3000/SS-B1000 speakers,and do note that those Sony speakers are "budget" choices that can definitely stand to be uprgraded some.
(They need some internal damping and real crossovers to begin with)

Dont get me wrong,it sounds good,way better than it should,but the Sony's were a compromise made due to the room,the speakers needed to be wall mounted so size & weight were key factors,as was cost,these got good overall reviews so I took a chance on them,and I'm glad I did,but no doubt they are'nt TOTL by any measure,and placement was a complete compromise due to lack of space.

Now the GFA-5200,that amp is out in the LR system (the LR is at least 3x bigger than the BR),and (for now) it uses a Kenwood Basic C1 preamp and a Sansui SE-80 EQ run thru the tape loop played via some JBL LX-44 speakers,and that one sounds really sweet,soundstage is very impressive for the $$$$ spent,only problem is I have'nt really been able to "open 'er up" just yet as there are always others out there,and the only time I really listen to it is late @ night when everyone else is asleep,soooo you get the picture.

Low volume listening has been awesome though,one nice feature on that Kenwood C1 preamp is the adjustable loudness,it adds just the right amount of "weight" @ low volumes w/o being hamfisted like an on/off loundness button often is.

And the JBL LX-44 are in another league compared to the Sony SS-B.

But I do feel the bipolar 535 seems to win in the bass department,it does'nt need any help @ any volume,the bass is THERE no problemo,on the other-hand the mosfet 5200 seems to be just a bit "leaner" in the bass department,but not in a bad way though,just different.

And the mids/highs,that's all colored by the difference in speakers,no way do the budget Sony SS-B's have the goods to compete with the JBL LX-44 and their awesome 026ti tweeters,so it's near impossible for me to compare the mids/highs of the two Adcom amps with such a major difference as that.

But like I said,soundstage & imaging on the 5200 ~ JBL combo is super.

So as they say,your mileage may vary.

I'll probably eventually fill out the Adcom mosfet line-up (maybe add a 5300 & 5400 for sure) so it's not like I dont care for the mosfet Adcoms,but maybe what I need to do is set-up a "head2head" shoot-out between the bipolar 535 and mosfet 5200 and see where I really end up on that deal.

Bret P.
 
Yeah I'd be interested to see them through similar speakers. I also wonder how much loudness circuits and eq use accentuates tendencies in the amps.

Thanks for the input!
 
asilker said:
Just bought a gfa 5300 but haven't been able to plug it in and get it going.

Anyway, regarding Adcom, I hear all over the place comments like "no slouch", "rated conservatively", "these have beef!", etc. Generally well respected brand known for having a few ponies under the hood.

Yesterday I read an interesting review on the 5300. Keep in mind, official literature for this amp claim 80wpc @ 8ohms mosfet design.
d6d298e3f3d21b59df120e698b743afa.jpg

This fella claims his buddy tested the amp at a whopping 120wpc @ 8ohms. That's quite a bit past 80wpc!

Has anyone else noticed this in Adcom power amps? Could this discovery be for real?
Click to expand...
Can you tell me how it worked out for you? I am thinking of buying one
 
Surprise, that post you quoted is from roughly 5 years ago, the poster may not even post here anymore. I've owned a 5300, they are based on mosfet output devices, so somewhat to the warm side of the spectrum. I liked the amp but since it didn't have speaker relays it would thump the speakers when turned on.

I believe some were made in USA but most were made in China. Some had a detachable power cord, but again most were "hard wired". You'll want to look elsewhere if you want a 12 volt trigger for turn on. If you're still interested, also look for the 5400 at 125 wpc. Adcom is still putting out amps, these days they are made in Taiwan.
 
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