Amplifier on a budget
Grabber70Mach
Posts: 64
As the title states I'm looking for an amplifier on a budget. This would be used to power a set of SDA CRS+ speakers that I recently purchased. Room size is approximately 14x15, but could possibly be moved to another room later that's 14x28. Here's a list of what I'm currently looking at, the upper priced ones are a stretch at this point but hoping that I could get a lower price. Keep in mind that I'll have to get a pre-amp if it isn't included already. This will be my first setup of this type.
1. Carver M-500t Power Amplifier - 250 WPC, Tube Sound 450.00
2. Adcom gfa-545ii 250.00
3. Adcom GTP-502 Pre-Amp and Tuner paired with Adcom GFA-5400. 300.00
4. Denon POA-8200 THX Dual Power Amplifier 240 Watt Stereo 2 Channel
270.00
5. ADCOM
GFA-5400 power amplifier
GFP-555 series II preamplifier
Adcom Speaker Selector
$299
6. Parasound 275 Two Channel Amplifier
250.00
7. Carver TFM-24 vintage audio amplifier
200.00
8. Adcom GTP-400 & GFA-545 II Combo - $400
9. Adcom gfa-535 II
150.00
10. Adcom GFA-555 Power Amplifier
450.00
What stands out? What is a hard pass?
1. Carver M-500t Power Amplifier - 250 WPC, Tube Sound 450.00
2. Adcom gfa-545ii 250.00
3. Adcom GTP-502 Pre-Amp and Tuner paired with Adcom GFA-5400. 300.00
4. Denon POA-8200 THX Dual Power Amplifier 240 Watt Stereo 2 Channel
270.00
5. ADCOM
GFA-5400 power amplifier
GFP-555 series II preamplifier
Adcom Speaker Selector
$299
6. Parasound 275 Two Channel Amplifier
250.00
7. Carver TFM-24 vintage audio amplifier
200.00
8. Adcom GTP-400 & GFA-545 II Combo - $400
9. Adcom gfa-535 II
150.00
10. Adcom GFA-555 Power Amplifier
450.00
What stands out? What is a hard pass?
Comments
-
I would also open up your search to Integrated Amps if you haven't been looking at those. If you don't already have a preamp, an integrated might be an easier solution. Separate Pre-amps have their benefits, but some of the well designed integrated amps can provide a very satisfying solution for less money and less potential headaches. NAD, Musical Fidelity, Cambridge, and even Yamaha make some good integrated amps.
For NAD, the C365BEE or C370 might be worth looking for. For Musical Fidelity, it might be hard to find something under $500, but you might get lucky. Just beware that any amp that is 20+ years old might need some refreshing. Amps that sound good usually run hot and heat over time wears out some of the components. Most of those Adcom amps you mentioned are closer to 30+ years old.
Post edited by billbillw on -
I would also recommend an integrated amplifier on that budget.
Enjoy! -
1. Carver M-500t Power Amplifier - 250 WPC, Tube Sound 450.00. IIRC Most if not all of these inverted the signal, IF so they ARE NOT SDA compatible.
With your SDA's you need to keep to a COMMON GROUND amp, some of these here are not
GFA-5400 power amplifier do not believe it is common ground.
Most if not all of these are old enough that you're taking a big gamble that it won't soil the sheets. When some of them DO soil the sheets they can and will take other gear with them, like speakers.
-
OK so it sounds like all the above are duds.
Looking in my area I found this:
NAD C356BEE Stereo Amplifier
300.00
Or
A bit closer yo me
Cambridge Audio A-300 Integrated Stereo Amplifier 40 watts / channel
100.00 -
The C356BEE might be OK, but that is significantly less power output than the 365BEE or C370 that I mentioned. If you keep the volume knob under control and listen below 85dB, it would probably be more than enough. They do have a reputation for needing some of the zener diodes replaced. Those tiny parts run hot and NAD probably undersized them from the factory. It would be a fairly easy update/replace/improve those if you can do even the slightest bit of soldering and know how to take stuff apart/put back together without breaking things.
The Cambridge is under-powered for a pair of SDA.
-
Also, don't rule out a brand new combo of something like a Wiim pro (as a streamer and preamplifier) and a cheap mono block pair of amplifiers. This cold be a temporary system while you save for an upgrade.
Stick around and keep an eye out on this forum as well. Many deals been had here over the years!
Enjoy
-
Conradicles wrote: »Also, don't rule out a brand new combo of something like a Wiim pro (as a streamer and preamplifier) and a cheap mono block pair of amplifiers. This cold be a temporary system while you save for an upgrade.
Stick around and keep an eye out on this forum as well. Many deals been had here over the years!
Enjoy
I thought that you couldn't use mono blocks because they wouldn't be a common ground amplifier? -
You are correct, can't use monoblock amplifiers.
-
You are correct, can't use monoblock amplifiers.Conradicles wrote: »Also, don't rule out a brand new combo of something like a Wiim pro (as a streamer and preamplifier) and a cheap mono block pair of amplifiers. This cold be a temporary system while you save for an upgrade.
Stick around and keep an eye out on this forum as well. Many deals been had here over the years!
Enjoy
Also, most Class D designs, even if not a mono-block, are not common ground. I was originally going to recommend the WiiM Amp Pro/Ultra, but then remembered the Class D limitations. That is essentially why I recently sold my W4S amplifier.
-
I would say none of the above and instead look for a Pioneer Elite SC** home theater receiver. Run in stereo it will power the CRS with no issues and you wouldn't have to get audio separates or an underpowered integrated amp until you could afford to do things right.
Plenty to look at on Ebay in your price range. -
A possibility?
Yamaha R-S202 -
A bit of a refresher on SDA amplifier compatibility might help. There is a bit of confusion between mono block amplifiers and two channel amplifiers that are bridged to a single channel amplifier. When a stereo amplifier is bridged the output transistors are configured so it is, in effect, balancing the two channels to power a single speaker. When the amplifier is in the bridged mode connecting it to an SDA speaker would short it out. This means using a bridged amplifier with SDA speakers is not a good idea. However, a single channel amplifier that has its negative speaker terminal connected to the amplifier's ground is perfectly acceptable. This means that two mono block amplifiers can be used with SDA speakers providing they have their negative speaker terminals tied to ground as any potential amplifier should. The usual testing to see if the negative speaker terminals are connected to ground can be done. The same as a stereo amplifier: with the SDA cable not connected and the speaker playing see if there is any AC voltage between the negative speaker terminal and any grounding point on the amplifier, such as the RCA shield. If not then nothing will be shorted by using the SDA cable.
The SDA speaker works best if there is a solid ground connection between the two channels. In a stereo amplifier this is provided by the internal grounding between the two channels. With two mono block amplifiers the two negative ground terminals could be connected with a length of speaker wire to insure a solid ground. So, bridged amplifiers are not compatible with a common ground speaker but mono block amplifiers should not be eliminated but rather go through the same checking process as any two channel amplifier. -
Where are you located? I’ve got a Harman Kardon 7300 that I’d let go very cheap. It was their flagship model and is a beast of an amp. Shipping probably not an option because it’s big and heavy. I assume it’d work with your speakers, but I’ll let others with more knowledge chime in.Things work out best for those who make the best of the way things work out.-John Wooden
-
Where are you located? I’ve got a Harman Kardon 7300 that I’d let go very cheap. It was their flagship model and is a beast of an amp. Shipping probably not an option because it’s big and heavy. I assume it’d work with your speakers, but I’ll let others with more knowledge chime in.
I live in Southern MD. -
Shipping would likely be more than the amp* would cost.
*To clarify, the 7300 was the TOTL AVR. It’s not a power amp, but has beefy amp section for an AVR.Things work out best for those who make the best of the way things work out.-John Wooden -
You are correct, can't use monoblock amplifiers.
Can the CRS use an isolation transformer for monoblocks? -
CRS+, yes. CRS blade/Blade, no.
-
Just saw this pop up local to me. NAD C422 and C372 for 200.00. Also still considering a refurbished Yamaha R-S202 2ch. Natural Sound 200W Bluetooth Stereo Receiver from ebay.
-
Those NAD you mentioned look like an amp and a tuner. You would still need a preamp? The amp would have plenty of power, but depending how much it has been used, it might need work. If low hours, that's a good deal for an amp like that.
That Yamaha is entry level and probably not great. It has spring clip speaker terminals, which screams low build quality.
-
When I enquired about the NAD he said it wasn't a common ground amplifier.
https://www.facebook.com/share/1E2g1bMaR8/ -
Oh. That's a C372, not C272. I misread. That's good. It's an integrated amp. I had one years ago. The seller is wrong. Those NAD are common ground. I'm using one from the same lineage, but newer, with my SDA-2B. I'd grab it for that price, but test it if you can to make sure it doesn't have issues. If it has low hours, it should be a nice amp for the CRS.
-
Oh. That's a C372, not C272. I misread. That's good. It's an integrated amp. I had one years ago. The seller is wrong. Those NAD are common ground. I'm using one from the same lineage, but newer, with my 2B. I'd grab it for that price, but test if you can. If it has low hours, it should be a nice amp for the CRS.
Is there any way to tell the hours on it? -
Not really, but if you take the cover off and see a bunch of discolored spots on the board (from heat) and everything is caked with dust and pet hair...that could be a sign of heavy use. It's really just a matter of luck. Some owners leave their gear on for 15+ hours a day, every day for years. Some only turn them on a few times a month.Grabber70Mach wrote: »Oh. That's a C372, not C272. I misread. That's good. It's an integrated amp. I had one years ago. The seller is wrong. Those NAD are common ground. I'm using one from the same lineage, but newer, with my 2B. I'd grab it for that price, but test if you can. If it has low hours, it should be a nice amp for the CRS.
Is there any way to tell the hours on it?
-
Short of taking off the cover, shine a flashlight through the vents to get a peek. If you have a multimeter, check the DC voltage across each channel's speaker terminals (pos to neg). It should be close to zero with the amp running with zero volume. Maybe up to 30 mV is ok, but anything more is a problem that could end up frying your speaker voicecoils.
-
Sounds good, I appreciate your time explaining it to me.
-
That HTS 2600 power filter included is a nice bonus. Looks like the seller kept his stuff clean. Maybe a gem
-
Short of taking off the cover, shine a flashlight through the vents to get a peek. If you have a multimeter, check the DC voltage across each channel's speaker terminals (pos to neg). It should be close to zero with the amp running with zero volume. Maybe up to 30 mV is ok, but anything more is a problem that could end up frying your speaker voicecoils.
Is this measurement done with the speaker load connected? -
No speakers connected, zero on the amplifier volume. It is a no load test. Just powered on for a few minutes at least.
-
@billbillw Thanks. Was hoping to check it out today but so far the seller hasn't gotten back to me.
-
No speakers connected, zero on the amplifier volume. It is a no load test. Just powered on for a few minutes at least.
I don't think you need to power the amp on to check for common ground.
