Input on new integrated amp purchase

rhythm

Hello,

I am looking at buying a new integrated amp, and it will be driving a pair of SDA 2B's. I want to make sure I get something with enough wattage, but I seem to remember it's also important to have something that can deliver high current for driving these speakers. I don't typically see specs on current when looking at amps online, so I'm seeking some guidance on how I can make sure I get something that will be up to the task.

Thank you,
Greg

F1nut

Hi Greg,

If the manufacturer specs do not include a peak to peak amperes rating you can look at the 8 ohm and 4 ohm ratings. If an amp doubles or comes close to doubling from 8 to 4 ohms it is a high current amp.

So, if rated at 100wpc @ 8 ohms and 200wpc at 4 ohms it is a high current amp.

Another aspect you need to consider is SDA speakers require a common ground amp unless you use the AI-1 or Dreadnought isolation transformer. Generally speaking, a dual mono integrated amp will not be common ground. If in doubt you can check with the manufacturer.

rhythm

Thank you! A couple of amps I've looked at are indeed dual mono, so I'll definitely double-check on these before considering a purchase.

Regarding power at different impedance values, several of these almost seem to be in a 'gray area', as the figure doesn't double but does move up significantly. Some examples are:

Atoll IN80: 80W @8 ohms, 120W @4 ohms
Primare I15: 60W @8 ohms, 100W @4 ohms
Marantz Model 50: 70W @8 ohms, 100W @4 ohms
Musical Fidelity M3si: 85W @8 ohms, 150W @4 ohms
Naim NAIT 5si: 60W @8 ohms, 95W @4 ohms

There are some others, but similar numbers.


Thanks again,
Greg

marvda1

Here's a Denon that doubles down.
https://www.crutchfield.com/S-HvqmVT7WkUP/p_033PMA1600/Denon-PMA-1600NE.html?XVINQ=BP0&XVVER=15JY&awcr=76622407358036&awdv=c&awkw=denon integrated amp&awmt=e&awnw=o&awat=&awug=&msclkid=6d04387ebaac178fe0655dcc65d0f5fa

Don't know the difference between these two amps.
https://www.bhphotovideo.com/c/product/1708005-REG/denon_pma_1700nesp_pma_1700ne_stereo_integrated_network.html?ap=y&smp=y&msclkid=780525ce6f1b1a21da17407c8e323716

F1nut

rhythm wrote: »

Thank you! A couple of amps I've looked at are indeed dual mono, so I'll definitely double-check on these before considering a purchase.

Regarding power at different impedance values, several of these almost seem to be in a 'gray area', as the figure doesn't double but does move up significantly. Some examples are:

Atoll IN80: 80W @8 ohms, 120W @4 ohms
Primare I15: 60W @8 ohms, 100W @4 ohms
Marantz Model 50: 70W @8 ohms, 100W @4 ohms
Musical Fidelity M3si: 85W @8 ohms, 150W @4 ohms
Naim NAIT 5si: 60W @8 ohms, 95W @4 ohms

There are some others, but similar numbers.


Thanks again,
Greg

Open box Marantz Model 30 for a shade more than the NIB 50. 100wpc @ 8ohm, 200wpc @ 4ohm. Yeah baby, high current.

https://www.safeandsoundhq.com/products/marantz-model-30-integrated-amplifier-open-box

Emlyn

I think the Denon 1700 is just the newer version of the 1600.

They're both fine products but the user manual cites power output into 4 ohms only at 1 kHz instead of full range like the Crutchfield listing says. Realistically it's probably 110-120 watts full range. Stable and not bad at all though. It would need to have a heftier power supply with big heat sinks to truly double down but then that's not necessary for it to do what it's intended to do.

Those SDA 2Bs can use a lot of power input to them and just sound better and better.

smglbrth

Interesting that the Model 30 specs state that both 100/200 watt ratings are at 1kHz. Not knocking it of course, just find it interesting.

I've had the 2A versions of the SDA and I wouldn't use an integrated, unless it was huge (EX. Musical Fidelity M6si). As Emlyn stated, IMHO of course, more power/current is better with SDA's. A decent integrated won't necessarily sound bad, just not what the speakers are capable of.

mhardy6647

smglbrth wrote: »

Interesting that the Model 30 specs state that both 100/200 watt ratings are at 1kHz. Not knocking it of course, just find it interesting.

I've had the 2A versions of the SDA and I wouldn't use an integrated, unless it was huge (EX. Musical Fidelity M6si). As Emlyn stated, IMHO of course, more power/current is better with SDA's. A decent integrated won't necessarily sound bad, just not what the speakers are capable of.

FWIW, I think sometimes we read more (or, perhaps less) into specs like this than they really indicate.
For example, the performance at 200 watts into 4 ohms at, say, 20 Hz might not be dreadful, but the HD spec might be high or the output might be, say 3 dB less (i.e., 100 watts). To rate at 1 kHz doesn't mean the component is incapable of operation at the extremes of frequency, although it does imply that it won't meet the 1kHz spec at "all hifi frequencies" (i.e., the FTC-mandated 20 Hz to 20kHz of old).

rhythm

Thank you all for the replies. The open box Model 30 is definitely a consideration.

It is an interesting discussion, seeing that some of the power ratings are at one specific frequency. I never really noticed this before, and I'm not quite sure what to make of it. I've checked out some other integrated amps since first posting and I have seen this kind of thing a few more times.

Question: For a given amp, if the 4 ohm power rating increases by 50 - 75% over the 8 ohm power rating, rather than completely doubling, should I feel that may not be enough to be considered a high current amp, at least for what the 2B's should be getting?

FWIW, I am currently powering my 2B's with the power amp section of an older receiver, an NAD 7400PE. I'm running the front L/R pre-outs from my AVR into the power amp in jacks on the receiver (it has actual jumpers between the pre out and pwr amp in that you can remove).

The ratings on the 7400 seem good enough to be using it for powering the 2B's, but if you feel that I'm not getting what I should be out of the 2B's with this amp feel free to let me know. I could shop for a preamp only and continue using the 7400 amp, if it's truly enough for the 2B's. Or perhaps both a new preamp and power amp if necessary.

I was thinking that I would want to bypass both the preamp and power amp in the AVR for dedicated 2 channel listening, which is what drove me to start shopping for integrated amps in the first place (with the HT bypass option). But perhaps with a good AVR this wouldn't be necessary (lots of opinions both ways on that), and I could continue just using a separate amp for the Front L/R channels.


Greg

rhythm

Thank you all for your comments so far, and I appreciate the suggestions. I think this is an interesting discussion, as I never really noticed before that some of these WPC specs are at one particular frequency only. Not really quite sure what to make of it.

For some of these amps that show a 50 - 75% increase in power at 4 ohms over 8 ohms, is that enough to indicate a high enough current output to properly drive the 2B's, or should I only be looking at amps with a full doubling of power at 4 ohms (or at least something like a 90% increase)? The 2B's are 6 ohm nominal, as opposed to some of the other SDAs which I think may be 4 ohm nominal.

FWIW, I'm currently using the power amp section of an older NAD 7400PE receiver to drive the 2B's. If I'm reading properly, I think the specs on the 7400 indicate that it's fully up to the task for properly driving the 2B's, but if you disagree I'd welcome the feedback. I definitely want these to sound as good as they can.

My current setup involves using an AVR to power my center and two surrounds, with the AVR's preamp out going to the power amp of the 7400 for driving the Main Front L/R channels. The main reason I started looking at integrated amps (with the HT bypass feature) is that I thought it might be a good move to bypass the AVR's preamp as well when doing 2 channel music listening. Perhaps this isn't necessary with a good enough AVR though.

Thank you,
Greg

invalid

You are thinking correct, I've never had very good 2 channel sound with the preouts of an avr.