Preamp
gain and hiss
May
14, 2020
Marc,
I
read your review on the CAT SL1 Ultimate Mk 2 preamp the other day. Well, I just purchased
one of these preamps; however, I haven't received it yet. My amplifier is a BEL 1001 Mark
5 with 26dB of gain, I think. And my speakers are 98dB-sensitive Horning Eufodites. With
this combination, what is your opinion regarding overall gain? Will I get a lot of audible
hiss from my system?
Andre
Traylor
Thanks for reading that review, which I wrote 13 (!) years ago. Since then,
Convergent Audio Technology has added gain switching in its preamps, so noise from using
them with amps that have high voltage gain is pretty much a thing of the past --
literally.
In
your situation, with an older CAT preamp, I would say that your BEL amp by itself won't
cause bothersome noise with a speaker of normal sensitivity -- about 90-92dB. However,
your speakers, at 98dB, are very sensitive, so whether background noise will be an issue
depends on your tolerance for it. I suspect there will be some background hiss, although
it shouldn't be noticeable when music is playing. And, of course, you own an audio system
because you will play music with it. -Marc Mickelson
"Audio-grade cable"
May
8, 2020
Dennis,
I
read with interest your piece on Roy Gregory's new music space. As you
pointed out, it sounds like a dream room for most of us.
What
really got my attention was part of the very last sentence: "I finally ended
years-long procrastination and switched out the Romex from my dedicated line for some
audio-grade cable."
I
would be interested to know exactly what kind of audio-grade cable you used. Twelve years
ago, I installed a dedicated line for my system and Caelin Gabriel (of Shunyata Research)
recommended that I use 10-gauge Romex and to avoid shielded or stranded cable of any kind.
This has worked out well, but I'm planning a new listening room with a better power system
to support larger power amps, so I know there must be something better than Romex.
Thanks
for the interesting article.
Bill
Ballard
The
subject is fascinating if a bit of a metaphoric rabbit hole. I couldn’t follow
Roy’s example as he used a product not available in the US, and perhaps not even
legal under local codes here. I’m not sure what Caelin Gabriel's objection to
stranded cable was. Everyone else I have ever discussed this with recommends stranded wire
for in-wall applications, and no one recommends Romex except as a last resort. I reached
out to Stirling Trayle, and he agreed that a stranded configuration has several advantages
over solid core, and he recommends 10-2 or 8-2 steel-armored cable, depending on the
length of the run. At the time I was looking for a product, my options were pretty
limited. I only needed a short run so wasn’t about to go to an electrical supply
house (where I would have to buy in bulk) or one of the handful of consultants who set up
studio electrical systems (too pricey for my needs). I recall there being three choices at
the time: JPS Labs, Audience and Cardas. None offers steel-armored cable. JPS Labs and
Audience were stranded and Cardas solid core, and all 10 gauge. The Audience in-wall cable
does not appear to be available any longer. I opted for JPS Labs cable. It is a finely
stranded 2 x 10AWG copper alloy (plus ground) in a twisted design to reject noise. At $30
per foot, it is reasonable by audiophile standards. It was a big step up from Romex. -Dennis
Davis
Add
me
May
1, 2020
Marc,
Please
add me to the e-mail list. Many thanks.
Ron
Brinsdon
You've
been added to the list. To join TAB's e-mail list and find out about new articles
first, send e-mail to rl@theaudiobeat.com.
-Marc Mickelson
