[jamesva3]

thank you so much! 

 I shall have your username carved in glorious perfection on the inside of my new sub $100 amp

 

[jamesva3]

Quote:

Don't remember I have said anything about gain control and clipping n the review. However, it will clip only if the input is too high. Normal iPod level of line-out (0.5Vpp) should be fine, but standard line-out (2Vpp) might be more of a problem. Though I really don't think that will be that much of a problem as max gain on PA2V2 isn't quite as high as you might think. It is a bit more complicated as gain on PA2V2 is set by the ratio between the variable resistor pot and the volume pot, and it will only go up that much before maxing out. I tried to set them in various configuration abd found out that in general, setting the varible pot in lowest position will give you much better control over the gain and useable area n volume pot. The claim on unlimited (or very high level of) of gain control, like many aspests of PA2V2 technicalitis, isn't really as good / accurate as it is. That's the reason why I recommend against it in the review.

From the review: "The 3^rd thing I noticed is the volume control, which if I am not mistaken, is more like a gain control. By setting the ratio between the two internal variable resistor switches and the volume pot, the overall gain can be controlled (and so as the output volume). The few problems are, 1) the two variable resistors are not always matched, even in their lowest position. I have to match them myself to balance the left and right channels using RMAA and Stepdance as reference. 2) Rising the variable resistor not only increase gain, but also decrease the usable area of the volume pot (causing pot to max out on gain even when it hasn’t reached its highest position). 3) Rising gain seems to worsen the performance of the chip"
 

I am not nit-picking, but i want to thoroughly understand amps before i buy one (me stupid), also i had the impression that increasing gain can cause destructive clipping if the device receiving the output has low ohm (like maybe 32 or 16?). Would portable amps offer any sound quality improvement if used in tandem w/ an xbox 360? i have noticed that my ath-a700s to be exceptionally underpowered in their soundstage performance which is what they are praised for. i also use a $2    m--m 3.5mm coupler and a $2 Rca--3.5mm male audio jack for audio, i think these might be the culprit (for bad sound quality) but i couldnt find any similar products that seem to be of higher build quality.​

 

[ClieOS]

As you have quoted, I have said nothing about clipping in the review. Increasing gain doesn't equal to automatic clipping. Sure, it happens when you set the gain too high for the amp to drive, but that's user error more than the fault of the amp. It is likely accident due to drunk driving but blames the car for poor handling. Also, it has nothing to do with the impedance of the headphone. You can over-drive a headphone, but not 'clipping' it. Clipping is an electronic concept only applies to amp, not headphone. More so, why do you want to over-drive a headphone when you have a volume knob to control the volume?

I don't have a Xbox and will not presume if an amp will make it sound better or not. I also never know that soundstage can be 'underpowered'. Soundstage don't need power, what it needs is good layer, transparency, resolution and imaging. An good amp can provide you will those qualities, but whether it will be an improvement relies on the whole setup, not just one individual components.

Don't buy into the cable myth. Sure, some good cable do sound better, but they are often the most minor of things to tweak for and many very expensive cable doesn't worth half the price they asked for, at least IMO. That's too much of a wishful thinking to believe that adding a $2000 cable in a $200 system will make it sound 10 times as good - not gonna happen.

 

[jamesva3]

alright thanks for the info

 

[Judge Buff]

Great thread, ClieOS!
 
I have a couple of requests/recommendations. fred_fred2004 has several amps <$100 with one being a Texas Instrument TPA "audiophile" version that I really like. The other is an 18V cMoy RA-1 (JRC4556) that I received today from an ebay auction. It is made by a vendor called ampedup77. This is a strong, "mint tin" amp, that is slightly warm & sweet (as an initial impression) and is a BIN bargain at ~$50.
 
If I had your expertise, I'd attempt to review them. As I don't have an iota of your knowledge, could you try to get them for review? Head-Fi users would definitely benefit from adding them to this comparison.

 

[ClieOS]

Great thread, ClieOS!

I have a couple of requests/recommendations. fred_fred2004 has several amps <$100 with one being a Texas Instrument TPA "audiophile" version that I really like. The other is an 18V cMoy RA-1 (JRC4556) that I received today from an ebay auction. It is made by a vendor called ampedup77. This is a strong, "mint tin" amp, that is slightly warm & sweet (as an initial impression) and is a BIN bargain at ~$50.

If I had your expertise, I'd attempt to review them. As I don't have an iota of your knowledge, could you try to get them for review? Head-Fi users would definitely benefit from adding them to this comparison.

I will add Howard (fred_fred2004) 3 channels portable amp (dual LM4562 + single LM6171) to the review soonish. It is a similar design to the cmoy2 I DIY'ed quite a long time ago and I believe it is Howard current top-of-the-line. Anyway, I'll see what I can do but my focus is on the sub$200 category right now, hoping to finish the review for them before the end of May. Would have finished the review by now but I am having a bad case of the flu for almost a week now and most of the time I feel like a zombie between the symptoms and the medicine.

 

[NoodleBoy91]

Great reviews. 
 
How about the fiio e17?

 

[ClieOS]

Great reviews. 

How about the fiio e17?

It will be in the sub$200 shootout.

 

[NoodleBoy91]

Quote:

It will be in the sub$200 shootout.

Oh cool 

 

[imackler]

Quote:

It will be in the sub$200 shootout.

 
Teasing us with your signature. That's cold, man.

 

[kenman345]

I just keep hoping a "[Portable Balanced Amp Shootout]" section in his sig. Can't seem to find much head to head battles between the different options.
Quote:

Teasing us with your signature. That's cold, man.

 

[ClieOS]

I just keep hoping a "[Portable Balanced Amp Shootout]" section in his sig. Can't seem to find much head to head battles between the different options.

Ain't there only 2~3 portable balanced amp in the market? I am not really that sure as I don't pay attention to them at all. They are mostly pointless for me as I can't / won't recable most of my IEM, especially since every balanced amp maker uses their own connector. That is the big reason why I go for StepDance in the first place - just as good as balanced amp, but without all the worries of recabling or future headphone upgrade. I don't see myself needing or wanting any portable balanced amp in the foreseeable future, so the chance of reviewing them is near zero.

 

[kenman345]

Your endorsement of the Stepdance is good enough now. And there are about 5 or 6 I believe on the market. with two different forms of connection, unless you count the secondary amp you can get for the hifiman 801 for balanced that uses a TRRS plug.
Quote:

Ain't there only 2~3 portable balanced amp in the market? I am not really that sure as I don't pay attention to them at all. They are mostly pointless for me as I can't / won't recable most of my IEM, especially since every balanced amp maker uses their own connector. That is the big reason why I go for StepDance in the first place - just as good as balanced amp, but without all the worries of recabling or future headphone upgrade. I don't see myself needing or wanting any portable balanced amp in the foreseeable future, so the chance of reviewing them is near zero.

 

[imackler]

So which amps are you adding to the sub-$200 shootout?

 

[ClieOS]

So which amps are you adding to the sub-$200 shootout?

Lear FSM-01, iBasso T3 and T5, JDS Labs C421 (AD8620 and OPA2227) and O2, Leckerton Audio UHA-4, FiiO E17, plus a reappearance of HeadRoom Total BiHead and digiZoid ZO2.3. The las t two have of course somewhat been reviewed in this shootout, but they will be re-listed solely because of their popularity in the forum.