REVIEW AND COMPARISON OF 21 HOME HEADPHONE AMPS add Yarland P-100
Mar 22, 2007 at 12:53 PM Post #33 of 85
Quote:

Originally Posted by Capt369 /img/forum/go_quote.gif
Yarland P-100. Beautiful looks and beautiful sound imo. I`d like your opinion on how it stacks up against the Doge, etc.


Maybe the OP and I could work out a temporary trade of his Doge and my Yarland
lambda.gif
 
Mar 22, 2007 at 2:13 PM Post #34 of 85
Quote:

Originally Posted by tbonner1 /img/forum/go_quote.gif
I am looking for more ideas on what amps to add for the next review(s).

Please let me know what you would like to see.


Meier Audio . . . . Head-Five, Aria, Opera
 
Mar 22, 2007 at 10:47 PM Post #36 of 85
I think it is unfair to put DIY amps (M^3, PPA, Pimeta) in the same list as the commercial ones. There is too much variation in their components to precisely pinpoint their sonic qualities. Changing the opamp in the Pimeta from the default OPA2132 to a OPA2107 can make a significant change in sound quality. Perhaps a separate list can be made or at least the components in the amps can be labelled clearer (ie. in the ranking's name itself).

Also, I think it is important not to forget about the Darkvoice 337. Despite the 337 and 332 sharing the same topology, the tube rolling choices for the 337 are much greater and varied than the 332, especially in the power tubes (6AS7 vs. 6C19).
 
Mar 23, 2007 at 12:53 AM Post #37 of 85
SKYLAB-I think the Yarland is a contender and thanks for your offer. However, for now I want to keep the Doge around for reference so I may just buy one.
 
Mar 23, 2007 at 9:34 AM Post #39 of 85
Quote:

Originally Posted by Knockturne /img/forum/go_quote.gif
I'm really interested in a comparison between the Doge and Heed.


i think it will be very difficult to compare a tube amp and a solid state. the sonics would be too different...
 
Mar 23, 2007 at 1:18 PM Post #42 of 85
Quote:

Originally Posted by cotdt /img/forum/go_quote.gif
i think it will be very difficult to compare a tube amp and a solid state. the sonics would be too different...


Well, not necessarily a comparison but I'd like to see where he'd rank the Heed. They're both in the same price range and I'd like to know which is better (they may be different states but one still has to be better).
 
Mar 23, 2007 at 4:45 PM Post #44 of 85
Mazuki quote-I think it is unfair to put DIY amps (M^3, PPA, Pimeta) in the same list as the commercial ones.

You are right regarding all the different configurations and permutations of DIY amps such as the M3, the PPA V1 and V2 and even the Pimeta. Your question is a good one that begs to be answered. When performing these tests how does one ensure a fair comparison?

I worked at a computer test lab in Los Angeles (right down the road from UCLA on Olympic Blvd.) and ran over 3000 projects. This question came up constantly when we did benchmark testing between competitive PC’s. We got into incredible battles over what was a “fair” configuration. If PC brand 1 beat brand 2 in a published test you can be sure I would have PC brand 2’s legal team call me to complain and demand a retraction because it was not an “apples to apples” fair and equal test. For example: PC brand 2 (the loser) had their top hardware “Evangelists” (aka gurus) argue that the hard drive had a faster seek time on PC brand 1 and that contributed to their margin of victory on intensive disk input/output tests. They were right.

We also did benchmark testing for AMD. If all motherboards were universal and (forward and backward) compatible with both Intel and AMD chips life would be easy and you could just benchmark the Intel, than change to the AMD. But life is rarely this easy (although it is in the case of changing compatible opamps even if you need a brown dog adapter).

The problem of similar headphone amp configurations is not only in the DIY domain. Look at the available configurations for one of the Singlepower amps:

Jensen Paper Oil Coupling
Capacitor Upgrade

Audio Note Silver Foil Oil Coupling Capacitor

Solen Plate Voltage Input Capacitor

High Frequency Bypass Capacitors

Black Gate Power Capacitors

Black Gate Cathode Capacitors

Neutrik Locking Headphone Jack

Goldpoint Stepped Atten.
(24 Steps)

Some might argue that if you had an M3 with a stepped attenuater beat another amp with a standard ALPS volume control that the reason might be due (in part) to the advantage of the stepped attenuater.

I am open to ideas on how to make the comparisons better. We can provide stringent functional specification requirements for each amp tested.

EXAMPLE

1-Each amp must have the power supply on the same chassis as the amplifier circuit.

This would eliminate the less expensive wall wart power supplies of many amps. But this requirement would also mean we would not be able to test the ASL MG HEAD MKIII, which only comes with a separate power supply.

Conversely, if we specify:

2-Each amp will have the power supply offered with the base priced amplifier.

Would it be fair to test the Musical Fidelity X-Can V3 with the basic power supply against the Samuels Raptor? The same argument can be made for the Gilmore Lite. In this scenario we are penalizing the company that offers the option of a less expensive power supply and rewarding the one with no option.

What I tried to do is provide pertinent configuration information for the tested DIY amp samples, which is what I did with the M3 comparison. I did specify the opamp as 8610 and the power supply by Elpac. I know this amp can sound better with better parts because I have heard them and I greatly respect AMB and Morsel. But this was the configuration tested and (for now) all I can do is provide that information and let the readers decide.

If I had the time, I would rate the amps in a table with quantitative numbers for each permutation. In order to be fair you would have to do this for every amp and almost every key part and it becomes a bit unwieldy for the average user:

EXAMPLE

M3
OPAMP 637 8
CAPACITORS BLACK GATES 9
POWER SUPPLY STEPS 9
HEADPHONE JACK NEUTRIK 8

TOTAL 34


M3
OPAMP 8610 7
CAPACITORS PANASONIC FM 7
POWER SUPPLY ELPAC 6
HEADPHONE JACK CARDAS 7

TOTAL 27

I would than have to rank them as separate amps:

EXAMPLE

1-Bada PH12
2-DOGE 6210



7-M3 STEPS WITH 637



14-M3 ELPAC WITH 8610



However, this only scratches the surface. What about tube configurations? Do you test with an AC power filter? What headphones do you use as your default? High impedance headphones will produce better sound with some amps. If we choose low impedance headphones as our single reference standard it will make many highly rated amps voiced for high impedance headphones sound less than optimal.

The list goes into the stratosphere and requires lots of work. My hat tips to Skylab for his effort.

For now, what I can do is list the specific test configuration. If I test another configurations (such as an M3 with 637s, STEPS, stepped attenuater etc.) I will rank it as a separate amp.
 
Mar 23, 2007 at 5:24 PM Post #45 of 85
tbonner1 - your reasoning on DIY amps being tested in one specific configuration is valid, but it still jumps out that the Elpac is a less than perfect power supply to say the least and pretty much sucks against a STEPS and the Panasonic FM's although good, are nothing to Elna Silmic / Cerafine / Black Gates.

A few of main specs would be very useful in describing the DIY designed amps and how they rate in their reasonable quality. Perhaps just the main few like Opamps, Power caps, and PSU would suffice (of course input/output caps and tubes if applicable).

This is mainly because you can build a $150 PPAv2 which will sound no better than a ok-spec'd Pimeta and you can build a $300 PPAv2 which will seriously kick ass.
 
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