Audio Buffer

Dear All,

I'm thinking of matching the ARC Ref 3 preamp with Mac MC501's. However, there may be impedance mismatch issues or will there? ARC Ref 3 impedance can go upto 1430 ohms while Mac input is at 18k-20k ohms?

Hence, I also plan to put in an audio buffer in between the pre and power e.g. Burson Audio Buffer AB160XLR

Has anyone experienced/ used audio buffer between pre and amp?

The ARC specs are 600 ohms output impedance and suggest a minimum of 20k ohms input impedance.

The Stereophile test results indicate a very low imput impedance on the Macs lower than you state above:

I have tried the Musical Fidelity X-10D with X-PSU between amp and preamp and it is not a pretty thing in a high res system.

Then again, the cost of the Burson is fairly negligible in the system context, so you can mess around and sell it if you don't like it.
I don't see any info on the Burson page about this particular application (they always show it between a source and preamp) or whether the buffer can handle the higher voltages of a preamp.

I actually have the older 100 model which I bought for a different purpose. I may try hooking it up between a BAT 3iX and a Bryston 3B-SST and see what happens. This is an impedance mismatch disaster otherwise.
I inserted the Burson AB160 RCA into my system (between the pre and amp) about a month ago, and I'm very pleasantly impressed (actually stunned) by its performance. My system is very transparent, highly articulate, and reproduces the musical emotion of the performance extraordinarily well. Over many years of experimenting with different components, I settled on the Placette Passive Preamp as the pre that provided my ears the most transparent and life-like articulate sound. The Placette worked well in my system. I had none of the negative characteristics (lack of dynamics, dull hi end) commonly ascribed to passives. However, I had my SACD player upgraded by VSE and its output voltage was reduced significantly, lowering the system's overall dynamics. I lived with this for several years while trying to compensate in other areas, eg, focusing on room characteristics, reducing AC mains distortion and noise, system vibration, etc. Although these adjustments improved the system's ability to reproduce music, I felt that its dynamics were still somewhat lacking. Since the Burson Buffer is inexpensive and had been reviewed most favorably, I thought I would try it---I had been considering it for some time, but thought it would lower the system's transparency, a characteristic that I highly value. Another factor that motivated me to try the Buffer is similar to yours: the Placette has an output impedance of 300 ohms and the input impedance of my amps (Odyssey Extreme Mono SE) 10K, not an ideal match. This, I thought, may also be interferring with system dynamics.

In spite of my reservations about transparency and adding distortion from another component, I tried it and it works beautifully. Surprisingly, I have loss NONE of the previous transparency, at least, I cannot detect any---hard to believe, despite the insertion of an active component and another set of 3' interconnects and all of varibles these two things inject into the system, but for some reason I do not hear any degradation of the musical information. It's a mystery to me. Dynamics in spades. Note: the buffer boosts the signal by 6db; when testing, be sure to compensate for this.

In short, I have no plans to remove the Burson from my system. I am quite pleased with its performance (remember: I've only had it in my system for about a month, but so far it has been great).
Thanks Rlxl
Does it mean the 6db boost will produce a louder voulmn only?
A louder volume and greater dynamics. At first, I wasn't sure about the extent of increase in dynamic range; but when I carefully controlled for the loudness increase that the buffer provides, the increase in dynamics became apparent---at least, in my system with my ears. YMMV, but I think lowering the output impedance of the pre resulted in increased dynamics.

If you decide to audition the Burson, be sure to post your results. I think this is a overlooked gem in maximizing one's system.
How did you control the loudness increase? Did you mean reduce the volumn? I feel any preamp needs to be clocked up to a certain point for them to sing best?
Yes, I reduced the volume at the pre to compensate for the 6db boost when testing. However, given that the output of my SACD player has been reduced and my pre is passive, the 6db boost merely gets me back to the output level before the mods to my player. It you're worried that the 6db boost would be too loud for your system and settings on your pre, contact Burson directly. While shopping for the buffer, a Burson rep told me that the 6db boost is adjustable to zero gain (or unity gain). Since I didn't have the buffer at the time, I didn't ask for specifics on how make the adjustment, and after I got the unit, I didn't feel the need to adjust the output, so I never followed up on the adjustment. The rep was very responsive to my inquiries and assured me that they would assist whenever needed. I hear you on the volume control adjustment on the pre. I would try the Burson in my system to see how it performs and then make any adjustments. And you might drop Burson a line for answer your questions