Passive Volume Controll for BADA?

[Jimmy3993]

Does anyone use a passive vol control for the berkeley audio dac?

I have a psychological problem with digital volume control. Too many bedtime stories about bits being thown away...

 

[Audio_ELF]

Try Music First's Passive Preamp

 

www.mfaudio.co.uk

 

[zerung]

I have had no experience with the Alpha DAC.

 

I use my DIY passive amp with Stevens & Billington TX-102. The sound is as good as my other preamp. I find the sound of the volume control on Amarra (digital) as good also. But this is a demo one, hence has its listening limitations.

 

There has been some comments from various industry luminaries on the digital volume control- in a positive way. One was Weiss on this CA forum and elsewhere. Please see:

http://www.computeraudiophile.com/content/Weiss-DAC2-Volume-control-how-good-it

 

[The Computer Audiophile]

In fact one of the topics at the Computer Audiophile Symposium was digital volume control. I knew many readers were skeptical about it and also wanted to know more, as did I.

 

When digital volume control is done "right" it's a fabulous thing. Also, don't forget analog volume controls have their own host of problems.

 

[Jimmy3993]

why would berkeley folk suggest that there is an optimum volume level?

in my setup w/o a pre, i am doing most of my listening between 20 and 30. am i getting all my bits?

 

[Synfreak]

Hi!

 

I´m using a (cheapish) TC LevelPilot between my source and the powered speakers.

This was thought out as an interims solution at the lowest price and acceptable look and quality, and had turn out to be quite satisfying for me (and my needs).

I`m planning to get a better solution as I will have changed my system to "computer playback" and a new DAC.

 

What is very important is:

- your source should have a high quality and low impedance output stage

- the source should have a switch/control to adjust the output volume according to the input sensitivity of your amp(s). (i.e. Like the new Weiss DAC2 has).

- the amp /or aktive speakers (as in my case) should - at least if the source doesn`t have one) sport a level switch or volume control.

 

The point is that you have to be able to set the highest needed volume with the analogue switches/controls (with a small margin left for extrem sports ;-) ), so that there is no need to use the digital volume control behind a "critical" setting. With modern high quality DACs and their low noise analogue electronics, these might be around up to -20 or -30 db.

 

Cheers

Harald

 

 

[BobH]

Hi,

 

I'm with Eloise on the Music First thing, it's one of the few pre-amps that I've heard that just gets out of the way. Expensive - but niiiiice!

 

As for needing a pre-amp in the first place - well, what does it sound like? If it sounds good, then it is good and you're done. If you can get you're hands on a decent pre, at some time in the future, you can always try it and see . As far as digital volumes go they have a different set of problems, as Chris said, but they are 'problems' just the same.

 

Bottom line? If you can't hear a 'problem' then there isn't one!

 

[Stretch]

Goldpoint make some nice, simple passive volume controls in the $300-$500 range using their own excellent stepped attenuators.

 

http://www.goldpt.com/

 

Or you can pick up an NHT pro unit for under $100 online. It works very well.

 

http://store.nhthifi.com/NHT-PVC-Pro?sc=12&category=1225

 

 

 

[Jimmy3993]

but I am pretty suggestable and I only had the berkeley for a few days.

However, I dont need switching and it would be nice to liberate $1700 or so from my pre if there was a more cost effective way to run the berkeley at it's "ideal" volume, rather than the low 20's which is where it was in my system with no pre.

From a self discipline standpoint, I had thought to wait till my pre sells to buy the berkeley. But I guess if I just went ahead and bought it while my pre was for sale then that would give me a much longer period to do real comparisons...

 

[The Computer Audiophile]

I'd pick it up now. You won't be sorry :~)

 

This opinion has nothing to do with Berkeley Audio Design being a paid advertiser here on CA. Rather, I use the Alpha as my reference and have been writing about it's wonderful performance since long before Berkeley was an advertiser. Just thought I'd mention that.

 

[Audio_ELF]

The problem is, using something like the Berkeley with a pre-amp thats of a lower level (even passive) is likely to be worse than using it with its digital volume. Yes you can buy the NHT for $100 ... but really! A $100 device between two multi-thousand dollar devices. I'm sure it sounds transparent with the kind of speakers and amplifier that costs a few hundred, but if you listen critically with a revealing system there will be distortion. A simple passive pre-amps is a potentiometer in a box - nothing wrong with that in the right context. However, a good passive pre-amp is not a cheep device. The Music First devices range from about £1600 upwards for example but competes (for transparency, etc) with active pre-amps costing a LOT more. (Sorry if this sounds like an advert by the way) the Music First pre-amp, instead of using resistors or potentiometers, uses a multi-tap transformer to attenuate the signal which reduces the distortion compared with using resistors.

 

Maybe your solution (if you end up running the Berkeley Alpha at a very low level) is to look at fixed, passive attenuators, then will be able to use the volume on the Berkeley at the higher end of the scale (i.e. around 80) where the bit reduction will be lessened.

 

Eloise

 

[emmodad]

there remains the pesky real-world problem of system integration when using additional sources requiring analog signal level management, such as phono preamp, reel-to-reel or SACD player [or even my (ancient but loved) Nak Dragon... anyone have a source for metal cassette tapes? ].

 

hence, until such time as BADA might create a new product adding an aux. analog input or two, and associated source selector (ie, a solution conceptually similar to the Benchmark Media update of the DAC1 family from DAC1/DAC1usb (only digital inputs) to DAC1pre (which includes an analog input bypassing the D/A section))... one needs maybe not a preamp, but at minimum a source selector.

 

various audiophile product solutions exist (preamps, passive attenuators and source selectors, etc), however they often have audiophile price points...

 

a potentially cost-effective option is to consider use of switcher and monitor controller units from the pro audio / studio world. as one example, Coleman Audio makes well-regarded products, several options in the range of USD 600-1000 (passive or active, 4-8 input pairs, multiple outputs ie to drive ie an external headphone amp or subwoofer(s) as well as your main monitors/amps).

 

if you are aware of the cable / impedance issues inherent in using a(ny) passive attenuator, and need to keep cost even lower, one other possibility is the occasionally-derided Central Station from Presonus. the TRS input paths (2, balanced) are completely passive through the attenuator; all source switching is done with relays. IIRC the attenuator is a relay-controlled resistive network. considering that CS typical price is under USD 500 (just looked, amazon is USD 458); can often be found on sale from pro audio internet dealers; and that several of those dealers (Musician's Friend comes to mind) run seasonal sales... it's an interesting bargain. i and others have acquired several around USD 300 new. look at CS as a clean passive control of multiple balanced sources; plus "thrown in for free" are (all not SOTA, but certainly convenient as backup): metering, headphone amps (2), 24/192 DAC with SPDIF TOS and coax inputs, and an Aux RCA input which performs level shift from consumer to pro balanced..... depending on your needs and beliefs, potentially a useful little box. i recall some extensive notes, pics and info in several head-fi threads, search for titles containing "central station" authored by "ferbose"

 

of course, if you simply feel the need to spend more, there are excellent monitor controller products from Crane Song, Dangerous Music, Grace, SPL......

 

one other reason i personally believe in using an analog monitor controller, especially in front of active monitors (I use Meyer and K&H; passive boxes are AE and PMC, also not inexpensive to repair): considering those rare but inevitable moments when your computer playback source.....glitches......and doesn't recover......and is putting out pure noise..... it's really useful to have a physical volume control (or even a physical panic mute button) that you can grab for near-instantaneous mute, and not be pushing a set of buttons trying to toggle down to zero. certainly cheap insurance versus cost of replacing tweeters and/or power amps, recalibration etc.

 

[Stretch]

Eloise, why would there be any more distortion from a decent attenuator or potentiometer wired straight through (see below) than there would be from exactly the same unit hooked up to the gain stages of any active preamplifier?

 

http://www.goldpt.com/sa1x_in_500.jpg

 

[Audio_ELF]

Passive compared with active pre-amplifiers distortion will be similar as part of an active pre-amp IS an attenuation stage. However my point was that using a $5000 DAC with a $100 NHT attenuator was rather a mismatch considering you are likely to be using several thousand dollars of power amp and speakers with the DAC. I've no experience of the quality of the devices at goldpt.com but they do seam to look to be quality devices.

 

The most transparent "pre-amp" I've come across is the Music First passive pre-amp, but thats going to cost as much, or more, as the OP would get from selling his existing pre-amp and as (he appears) to want to sell the pre-amp partially to fund the DAC thats not going to make economic sense.

 

Eloise

 

[Jimmy3993]

I was hoping that I could sell my pre to take some of the sting out of the price tag on the berkeley. It had been billed by most everyone as best when run direct.

So when I got the audition unit, I plugged it in next to my current dac (benchmark dac1) and ran them both to my jeff rowland capri. From there i ran to some jeff rowland model 7 monos and audio physic scorpios.

Playing the same files to both the berkeley and the benchmark, it was clear to me VERY quickly that I preferred the berkeley. So I then took my pre amp out of the mix and was suprised to find that some of the magic and wonderful detail seemed to have went away as well. Really surprising given that most reports were that the berkeley was preferred w/o a pre in the signal chain.

That got me thinking. And all that I could come up with was the fact that I was running the berkeley between 20 and 30 on its volume when running direct and maybe it was meant to run "direct" but not at levels that low.

The way that I see it, I have a few coices - Hold on to my pre amp and tell my kids that they need to wait a few weeks before eating, explore adjusting the internal gain switches on my amps or try a less expensive passive attenuator.

 

[Jimmy3993]

if I get a good offer for my pre, i'll take it. If not, I will have more time to spend deciding which volume controll I prefer.

This should complete the core of my system. It is funney. I spent months looking for the "right" cdp because I didnt think that I could get good sound from a computer. Glad this site exists!

 

[Stretch]

One brand new option that looks like it might be a pretty good one. The First Watt B-1 buffer preamp, built by Nelson Pass on his own kitchen table and selling for 15% off MSRP on Audiogon right now.

 

http://www.enjoythemusic.com/magazine/equipment/0708/first_watt_b1_preamplifier.htm