• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

What Amplifier?

M

mbeigh

Active Member
Iam powering a pair of Infinity RS IIIa speakers with a Hafler DH-200 amp and a Hafler 101 preamp. I can't help but think that I could get more out of them with more watts. My sources are pretty good, NAD 542C CDP and a Rega P2 tt.

I was thinking about an Adcom GF-555 but don't have any idea which preamp to use. My budget is around $500 for both units. Am also open to other brands or units. Just looking for a good, affordable 150-200 w set up.

Any suggestions or ideas would be welcomed.

Thanks,

M Beigh
 
Register to hide this ad
That is my intention. Didn't know if the Hafler pre had a good reputation. I do know there are some mods for Haflers.

M Beigh
 
the hafler pre-amps are well regarded- both the 101 and 110, with modded 101s much enjoyed.

That's a good amp as well- consider the larger 500. Also the larger Adcom sounds like a nice choice. And later one of infinity's bigwigs ( I can't believe I'm not recalling his name) went to work for ps audio. I like most of their stuff too.

Recently spoke with a few folk about two other amps- the Accuphase and the Audio Research gear. Pricier, but can be found at times for a good price. This stuff is extremely well built.

Lots of other good amps out there from smaller botique companies too- I'm fond of B&K's bigger offerings, as well as PSE, and one more brand I won't mention yet as I'm on the hunt for one...
 
All good advice about powering Infinities. Yes, bigger amps with LOTS of headroom and ability to handle 1~2 Ohm dips will make them sing. The amps mentioned are all good choices.

Also, some members are using large Yamaha amps to good effect. A few are using Bose 1800 amps (IIRC) to good effect. Both may be available for moderate cost? And of course there are a few Sunfire/Carver amps doing Infinity work.
 
The GFA-555 is an excellent match with RS-IIIa's. I used a 555 Mk II on my IIIb's for many years with fine results. As others suggest, no reason not try the Adcom in place of the Hafler amp first while keeping the rest of your system the same. The 101 is a well-respected pre- and may well match up very well with the Adcom amp. You can always swap out pre-amps later as funds, time, and desire allow.
 
I am picking up a GFA-555 tonight. Am anxious to hear how it compares to the Hafler. I am going to use my Hafler preamp.

M Beigh
 
Hmmm, if your not getting the SPL's you want, you might want to consider more sensitive speakers. The volume difference between a 200W and 500W amp just aint there. I experienced a similar situation with B&W 801's series 1. We threw 500W of Kyocera amp at them and could hear the clipping at not too large of a sound pressure level. What's worse is, we could hear the speakers become softer when we turned up the level, demonstrating thermal compression ocurring in the voice coil. At lower volume settings, the speakers sounded great: ....smooth, flat, etc. They just couldn't play loud if their lifes depended on it. To make the most of your speakers sensitivity, make sure your listening area is not overly absorbent. I like Haflers, or MOSFET amps, for low impedance loads. They might be a little more lossy output (higher output impedance when the devices get hot), but that might save you a repair bill when driving 1/2 ohm loads.
 
Some other considerations - and I had the same Hafler setup as you back in the 90s:

- What size is your room and how loud do you like to run? This pretty much determines your wattage requirements. I suspect the Infinities are pretty inefficient, so that adds some to that part of the equasion.

- Since you didn't describe exacly what you're most dissatisfied with, then you might want to consider a couple of things on the Haflers:
- Update the preamp first. I did this with my setup and discovered that the ARC LS3 I purchased - used of course - was a really weak link. I did some of the Musical Concepts simpler mods such as replacement transistors and power supply updates but they didn't do as well as a complete replacement of the unit.
- Update the Hafler power amp: I am a fan of the Musical Concepts replacement driver boards for the Hafler gear. These _do_ make a big difference and are not that hard to install, although I'd consider it a good intermediate level DIY project. The problem here is that the money invested will likely not be returned for swapping out the Hafler.

- The B&K, IMHO, is a sideways move.

Bottom Line:

- I'd look to improve either the pre or the power amp.
- Go with the preamp first.
- Go with the power amp next unless.....
- Your room/playing levels dictate that you deal with this first due to the speakers you're using.

Cheers,

David
 
The Infinitys are singing!!!! The GFA-555 is aworld of improvement on the Hafler. Much better soundstage, smoother , more headroom. I've got Tingstad and Rumbel in my listening room live and in person. Great sound from their Pastorale cd.
 
You must log in or register to reply here.
Back
Top Bottom