Amp for SDA 2A
Hansen2112
Posts: 13
I need to decide between these two amps for my SDA 2a's. Adcom GFA 555 and a Marantz Mm7025.
The Adcom is an old favorite but has no speaker protection and probably at least 20 years old. I know these sound good but I'm worried about the age and lack of speaker protection.
The Marantz is fairly new at 140 watts per Channel. Has some good reviews but don't know too much about it.
Both are approximately the same price, which one would you guys pick and why?
The Adcom is an old favorite but has no speaker protection and probably at least 20 years old. I know these sound good but I'm worried about the age and lack of speaker protection.
The Marantz is fairly new at 140 watts per Channel. Has some good reviews but don't know too much about it.
Both are approximately the same price, which one would you guys pick and why?
Comments
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I don't think either one is a good match for the 2A's, I drove my 2A's with an adcom gfa555 for a number of years it had grainy sounding high frequency and it overheated quite a few times. The 2A's are a tuff load for amps, that aren't rated down to 2ohms. The parasound A21 would match better and has a more stout power supply than either of the amps you mentioned. Plus if the adcom hasn't been recapped and properly serviced it will blow up, I know from experience.
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Thanks for your response. Looked at that amp and little out of my price range unfortunately.
Another amp I've got a line on is a Crown XLS 1500. From what I understand this is a pro amp but also used for home audio and can drive pretty tough loads. Anyone have any experience with Crown? -
There's two things you do not want to skimp on. Your amp, preamp, source, cables and whiskey. No one likes cheap whiskey.Gustard X26 Pro DAC
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There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
Save up and keeping looking.Political Correctness'.........defined
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Ran my old pair with a B&K Reference 200.2. The amp did a pretty good job but they are getting a little long on the tooth nowadays, unless they've been serviced.Remember, when you're running from something, you're running to something...-me
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IN GOOD CONDITION, Adcom hands-down. Problem is, it'll have to be rebuilt to be in good condition. The caps are ancient. Nice basic design, just needs some new parts 'n' lovin' to be good-as-new.Hansen2112 wrote: »I need to decide between these two amps for my SDA 2a's. Adcom GFA 555 and a Marantz Mm7025.
The Adcom is an old favorite but has no speaker protection and probably at least 20 years old. I know these sound good but I'm worried about the age and lack of speaker protection.
Or invest more, and get better-than-new with various aftermarket sources for circuit boards, etc.
Attempted to look at the specs on the Marantz web site.Hansen2112 wrote: »The Marantz is fairly new at 140 watts per Channel. Has some good reviews but don't know too much about it.
https://www.marantz.com/en-us/product/av-separates/mm7025
They don't list a proper FTC rating. No speaker load mentioned (probably 8-ohm, with no recommendation for any lower load such as 6- or 4-ohm; and you're gonna need something that can handle 4-ohm nominal loads without crapping the bed.
They do brag up that it's got 30,000uF of power capacitance. That's about a third of the Adcom, I think. Weak.
8Hz--100kHz +/- 3db. Not great.
Made in China.
I wouldn't touch it with a ten foot pole. Cheap, yet WAY overpriced.
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It's made in Vietnam now.
Rated at 2x 140 Watts (8 ohm) / 2x 170 Watts (6 ohm) 0.03% THD.
What the hell is wrong with that spec? The Adcom is rated at 20Hz-20kHz, with 0.09% THD8Hz--100kHz +/- 3dbThey do brag up that it's got 30,000uF of power capacitance. That's about a third of the Adcom, I think. Weak.
The Adcom has 60,000uF. Of course, it's a more powerful amp, so it needs more capacitance.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I was going off of the photo on the manufacturer's website. Viet Nam is potentially worse. China has an established manufacturing base while Viet Nam is still building theirs. I'm not a fan of either one.It's made in Vietnam now.
I totally missed the 6-ohm rating. Is it on the Marantz web page I listed? Still not good enough for 4-ohm nominal speakers.Rated at 2x 140 Watts (8 ohm) / 2x 170 Watts (6 ohm) 0.03% THD.
I'd expect to see about half that deviation in top-flight equipment. 8 or 10Hz--100kHz at ~1.5 db. Not a big deal, but clearly not in line with better solid-state gear.
What the hell is wrong with that spec? The Adcom is rated at 20Hz-20kHz, with 0.09% THD8Hz--100kHz +/- 3db
I don't know why you're comparing power deviation/power bandwidth, to THD in the "audible" frequency range.
I didn't realize the Adcom had only 60K uF, for it's 23 dBw output. The Marantz outputs 21.46 dBw, has 30K uF. It shows in the lack of low-impedance drive capability--although there could be output-device and/or heatsink issues too.They do brag up that it's got 30,000uF of power capacitance. That's about a third of the Adcom, I think. Weak.
The Adcom has 60,000uF. Of course, it's a more powerful amp, so it needs more capacitance.
And that's from an amplifier advertised as having a "high-capacity power supply".
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Are you on drugs!?!Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
I have that Marantz and it's not a bad amplifier. Sure there is bigger and better, as there always is. Granted, it's went up in price in the last couple of years from when I bought mine. However, as I said, for what it is and for intended purposes, it's pretty nice and sounds good. I wouldn't recommend it for the 2A's just because of the 4 ohm load of the 2A's (had those too, not at the same time with the Marantz). I know that the 2A's, when pushed, will suck power like no tomorrow.
However, as I said, it's not a "bad" amplifier...Remember, when you're running from something, you're running to something...-me -
Find a ps audio 200cx, there about $600/$750
200 wpc 8 ohm and stable to 1.5 ohm load -
@Hansen2112 ...this amp will give you all you need and then some more
Great seller to boot
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