They answer the phone. You often get Frank when you phone.I have sent him email twice about it and he has never answered.
They answer the phone. You often get Frank when you phone.I have sent him email twice about it and he has never answered.
Another variable that cannot be forgotten in this type of blind test are the headphones being used as well as the exact output volume/power level.
Yes, for sure, the headphones matter less if he is doing a DAC comparison. What I had in mind was a comparison between two different amplifiers, say one discrete and one op-amp based.For a level matched comparison of DAC's the only concern is having a good enough headphone (and he has those) and an amplifier with low distortion (which he also has).
When comparing amps with different gain (or when switching between gains) one has to carefully 'match' the levels. After that I don't think one can reliable tell amps apart. Subjective reviewers are highly unlikely to do this within 0.1dB and that's where the 'reports' come from. Incorrectly performed tests.
It may be worth noting I haven't seen @GoldenOne post anything here about the 'upcoming test' and would be interested to know if he would show the entire process and outcome on his YT channel.
For a level matched comparison of DAC's the only concern is having a good enough headphone (and he has those) and an amplifier with low distortion (which he also has).
When comparing amps with different gain (or when switching between gains) one has to carefully 'match' the levels. After that I don't think one can reliable tell amps apart. Subjective reviewers are highly unlikely to do this within 0.1dB and that's where the 'reports' come from. Incorrectly performed tests.
It may be worth noting I haven't seen @GoldenOne post anything here about the 'upcoming test' and would be interested to know if he would show the entire process and outcome on his YT channel.
May I suggest two things to consider, please?
- 1) Both channels should be measured properly with a True-RMS voltmeter or an oscilloscope and posted in the dedicated thread/test/review; playback signal should be mono, not stereo (or channel inputs should be reversed and output voltages should be remeasured for perfect accuracy between the two channels).
- 2) A/B or A/B/X tests should also be conducted in mono, not just in stereo.
Thank you!
I wrote him a couple months ago about that unit and also never heard back. Seems kind of retired?.I have sent him email twice about it and he has never answered.
We have refined the design of our ABX component comparator and also made it much more affordable.
It now is direct coupled in to out (no capacitors in the signal path, no active solid state components, just carefully designed pop free relays and instant quiet switching with silicon volume controls for exact level matching.
It allows direct comparisons of two preamplifiers, two power amps, and three set of speaker systems either separately or at the same time. It even allows comparisons of interconnect cables.
Here are the details:
The price is $999
ABX Switch, rev 2, by Audio by Van Alstine 01-26-14
The ABX Switch allows seamless switching of up to two sources, two amps, and three sets of speakers.
Controlled by universal remote, usually from the listening position, the ABX switch has the capability of:
• Precise volume level matching, within 0.1 db, of any selected system.
• Infrared universal remote control.
• Blind test mode (2 of them) can force evaluation strictly by how it sounds.
• Works with or without a subwoofer.
• Programmable power up state and adjustable display brightness.
• Persistent volume settings power up the same as they were when last powered down.
• Multiple systems can be set up permanently and switched in/out instantly with remote control.
• Low noise
• Built in “Y” splitter can be used to drive two units with one source
• Allows selection of up to two speakers at the same time
• Mute entire system with a single button
• Gold plated RCA connectors for line level signal connections
• Gold plated 5-way dual banana connectors for speaker level signal connections
• DC coupled (no capacitors in the signal path).
If you are interested, contact me and I can e-mail you the full operation manual including photos inside and out.
Interesting things you can do with our ABX comparator:
If you want to make a quickie and easy blind test of two power amplifiers, for example. Attach them both to the ABX box, use the ABX box level adjustments to match signal levels from each, then simply hit the botton that turns off all the indicator lamps on the ABX box. Switch back and forth rapidly between the two amps under test a few times on the same program material and you will soon loose track of which amp is which. Then do more careful listening and when you are certain of which amp you are listening to, turn the indicator lamps back on and see if you are right. Repeat process several times. Can you really pick out what you are hearing? Once you loose the ability to hear with your eyes, all bets are off.
Of course you can do the more formal built in test procedure for the most accurate and foolproof results too.
Do you want to see if your favorite wonderful good sounding capacitor is really really better. For this you will need two identical samples of the component you are playing capacitor swaps with. Put all the good sounding parts in one sample, keep the other one stock, and run the ABX test between them. How wonderful are your capacitors now?
You can even put interconnect cables to the acid test by using two identical preamplfiers.
There are many ear opening things the ABX box can help you understand.
If you are a speaker manufacturer or audio electronics manufacturer you definitely need our ABX box. You probably will find it is your most important test too.
Frank
E-mail me at [email protected] with your e-mail address and I can send you a .pdf file of the user manual complete with photos and hookup diagrams.
It's all in the coat hangers mate... coat hangers.Otherwise where is the “science”?
Sorry, I was in the process of editing my post and messed up your reply. I’ll repost it.
No worries, I thought you'd chosen to remove the post so I thought I should remove the quote from mine... now it's all in a right state.Sorry, I was in the process of editing my post and messed up your reply.
If it is a gamble then it must be some of the best odd's ever.gamble $1K
Hence how I'm all prepared as before.I do enjoy a bit of theatre
Yeah, I need to dig out the popcorn maker.No worries, I thought you'd chosen to remove the post so I thought I should remove the quote from mine... now it's all in a right state.
If it is a gamble then it must be some of the best odd's ever.
Hence how I'm all prepared as before.
JSmith