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Merlin owners, AC or battery for BAM?

I recently purchased Merlin VSM-MM's with the Super Bam, simply wonderful speakers! However, I am experiencing a rather unexpected result in preferred modes of Super Bam operation. I find myself much preferring the full AC mode to full Battery mode (PC unplugged). In battery mode the sound is simply too dark, warm, resonant and lacking in dynamics, the sound is simply blah! In AC mode the sound is much punchier and involving; greater dynamics, more presence and tighter bass. There is also absolutely no loss in refinement, the noise floor seems to be just as low, no issues with grit or grain.
I am simply stunned by these results having heard so many good things about the battery BAM vs. the AC BAM. I can only surmise that all the work I've done with my AC is responsible. This includes dedicated, seperate AC lines for both digital and analog, dedicated grounds and power conditioners; BPT 3.5 Sig. for analog (I plug Super BAM into this) Shunyata Hydra 4 for digital, VH Audio AirSines, Shunyata Cobra and Python VX and Purist Audio Dominus power cords. I'm thinking that my AC noise floor is competitive with Battery mode, and the negative things I'm hearing with the Battery mode are symptomatic of this mode of power.
I recall reading a number of reviews over the years in which battery powered equipment has been criticized for some of the symptoms I'm experiencing, could this criticism be legitimate in this instance? I have also personally experienced some of these same symptoms with a N.E.W. DCA 66 amp I own which further reinforces my thoughts on this.
I'm just wondering if any other Merlin owners have experienced these symptoms, or whether it could be some lack of synergy in my system that is causing this?
I also experimented with different power cords on the Super Bam and this further changed things, ie. I'm thinking a real nice PC here will further improve things, any thoughts?
Equipment:
Perp. Tech. P1A, P3A, Monolithic PS, Modwright Signature mods, Revelation Audio cables, P3A chassis out of case (case adds capacitance)
Audio Logic 24mxl
Proceed CDD
Joule Electra LA 100 Mk. III
Art Audio Carissa Signature
IC's-Cardas Golden Ref., Purist Audio Venustas and Dominus, Ridge Street Poiema
Speaker-Synergistic Resolution Ref FX X2 biwired
Also full room treatments-Echobusters, Doublebusters, RPG Pro Foam and Skylines, DIY 16" tube traps
sns

Showing 2 responses by dgarretson

dgarretson
2,594 posts
 
Did you buy them new or used? If used, how many hours of play time do you have in battery-only mode before the BBAM loses power? Your problem may be weak batteries.
dgarretson
2,594 posts
 
Sns,

The VSM-MX's I bought used were about 2 years old & came with the standard BBAM (pre-SuperBAM). The batteries were giving out after about 4-6 hrs of use in battery-only mode (vs. advertised 12 hrs.) After taking the BBAM apart, I determined that two of the four NiMH batteries could not take a full charge. But even so, the battery-only mode still sounded better than AC-only mode or AC/DC hybrid mode.

I decided to upgrade the BBAM myself to much higher performance with low-impedance SLA batteries, more & better filtering capacitors, and most importantly, removing & bypassing the 3-pin DC regulation stages. The improvement for the system was on the order of 40-50% in smoothness of treble & midrange, resolution, transparency, dynamics, bass extension and control. I have spoken with Bobby about the SuperBAM. He believes it achieves similar improvements with upgrades to NiMH batteries, filtering cap, 3-pin regulators, and AC converter. He told me that the AC-only mode of the SuperBAM sounds better than the battery-only mode of the standard BAM, but that the battery-only mode of the new BBAM is better yet.

Dave
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