Wow. Used from $660 on Amazon.com. Black Friday in early October?

http://forzaaudioworks.com/en/product.php?id_product=73

Quote: There are 4 version of this unit on Amazon. Can buy any of them, or Gigabit version only needed?

Yes, important. And it's sad to hear about bad isolation. But TH900, according to information from  closed headphones comparison thread, actually is open-back: "Very close to LCD-XC sound wise, lighter and extremely comfortable, but almost no isolation". It's pity, that there is no T5p 2gen in...

Hi. Did anyone compare T5p 2gen and Fostex TH900? Are they play in one top league or one of them is in the higher class? What are the essential, fundamental differences between them? And what of them have better isolation from external noise? Eventually, I narrowed the choice down to T5p 2gen...

Oh, thanks! You tested and compared many different closed-back headphones with DP1 and in the end choose TH900? Or just bought TH900 and they've satisfied you at once?

Hi! Looking for closed-back headphones (about $1000 price maximum), that will be in full harmony and compatibility with DP1. So, what closed-back headphones will be the best for DP1? Denon 7100, Sony MDR7, Beyerdynamic T5p-2, Fostex 600/900?

Good idea to feed F1 from Teradak only (without any additional devices). Could you compare the differences in sound quality feeding F1 from USB and from Teradak?

What about using F1 and X1 as is (without any additional devices) and use standard USB cables versus Breeze U8? PC>F1>DAC vs PC>Breeze>DAC - if F1 will be better, so does it worth additional $67? PC>X1>DAC vs PC>Breeze>DAC - same price, so same sound quality or one of them will be better?

Hi. There are two identical connectors on the F-1 plate (red marked). What is their function? Any thoughts?

Here is a question in 501's inputs quality and in quality of feeding source. USB input, in comparison with coax input, has two advantages: DSD and possibility to use Teac HR Audio Player. But, if DSD and player are not important, I believe, that coax input with quality feeding source, ceteris...

Thanks! I will try to do that.   Anyway, what to upgrade - USB or coaxial?

37mil, thanks for very helpful and detailed description! But it's difficult for me to do all these updates at ones. It will be better to move step by step, from simple to complex. So, the first step will be to change audio output and headphone apm caps: I'm not sure about my preferences...

There are too many caps in the 501. Here is the photo of all of cap's groups, that I found and mark:   Could you specify the parameters of the capacitors (manufacturers, models), which you replaced the original capacitors in each of the groups?

I decided to improve sound quality of my 501. First of all, I want to upgrade transport quality, but no sure: usb or spdif. My music collection is redbook and vinyl rips. No DSD. So, what will be the best: upgrade usb transport (with Uptone USB Regen or Wyrd or iFi USB Power) or upgrade coaxial...

Could you share with the impressions of comparing The Breeze Audio and Gustard U12? Which of them gives better sound quality?

They say, that XMOS or Amanero plates are the best and provide the best sound quality. I'm not expert too. But I'm afraid, that it's not possible, 'cause Teac's USB plate has original jacks and connection.

Interesting, is it possible, some how, to replace original Teac USB plate with XMOS or Amanero plate?

Faithless, thanks for review! And great photo!  

How about compare Schiit Wyrd and iFi iUSB? Will be any differences for UD-501?

stuartmc, So, it has been a while since you compare X12 vs S16. Could you bring the final compare? Shortly. Pos and cons for each model.     May be anyone suddenly compare Teac UD-501 and X12 and/or S16?

Beyerdynamic DT880 Premium 600ohm + Gustard H10=Love or Hate)? Is anybody try it? Can H10 fully drive this headphones? And what about compatibility ( dark/light sound)?  

stuartmc, thanks for review! And what XLR cable do you use to connect s16 and h10? I believe, that my future setup will be s16+h10+dt880 (600ohm).

Yes! It's very interesting. I was in one step from purchase s16. But x12 brought some indecision.  

Are there any differences between balance and unbalance inputs? What is the better for the best sound quality?