Those Lepai Tripath amps are supposed to be excellent, considering the price.  I'm intending to get a couple to use as mp3 player docks around the house, eventually.

Nice write-up!

I don't claim to know much about the sonic advantages of balanced over SE, but I find it curious that you could hear a difference between balanced and SE cables connecting the dac to amp, with only SE headphones.  Did you try any blind A/B-ing on this?

Quote:

Originally Posted by acidbasement 

Nice write-up!

 

I don't claim to know much about the sonic advantages of balanced over SE, but I find it curious that you could hear a difference between balanced and SE cables connecting the dac to amp, with only SE headphones.  Did you try any blind A/B-ing on this?

I would need someone to help me during the blind test so no I didn't but I'd be game to give that a shot to see if it was all in my head. It would make for an interesting meet and a few yucks. Heck I'd even ask someone to film it for my YouTube channel. The next step is to get a balanced cable for my customs or future other customs.

Quote:

Originally Posted by Armaegis 

 

It's not a DIY; they're a (presumably) Chinese brand that someone's selling here. You can actually find it for marginally cheaper online. Still, $25-30 for a power amp is pretty cheap. I don't think that thing has a headphone output though, unless you wire up some resistors or something appropriately. 

 

We did have a local guy making dacs and amps though, he goes by hotaudio. I have one of his usb-dacs in fact (very nice sounding for the price). I've invited him out to meets and stuff before, but he's never attended. Kinda odd, considering we'd be his best target audience. 

I have one of those Lephai amps. Its actually not terrible a little hissy and underpowered but detailed none the less.  I would probably recommend buying one of the 2020A boards of thievesbay for about 10 bucks and doing some modding. Pull the high pass filter caps use a decent power supply and away you go. This is an internally bridged amp so connecting the grounds on the two channels is a very very bad idea (if you have recabled phones it is a fairly good amp for hard to drive beasts).

There used to be a heap o' threads on modding these on DIYAudio that had some good advice on squeezing every last molecule out of them.

Quote:

Originally Posted by DigitalFreak 

Check it out guys, my article went live this morning. I hope everyone enjoys the read, I personally quite enjoyed writing it. As you guys can tell I'm quite happy with my CLAS rig.

 

Upping The Ante: The CLAS-db/ALO Rx MK3-B Mobile Rig

Going balanced lies madness I tell you! Thankfully I don't have any "proper" balanced gear, just speaker rigs hooked up to a 4-pin XLR.

Quote:

Originally Posted by Hutnicks 

I have one of those Lephai amps. Its actually not terrible a little hissy and underpowered but detailed none the less.  I would probably recommend buying one of the 2020A boards of thievesbay for about 10 bucks and doing some modding. Pull the high pass filter caps use a decent power supply and away you go. This is an internally bridged amp so connecting the grounds on the two channels is a very very bad idea (if you have recabled phones it is a fairly good amp for hard to drive beasts).

There used to be a heap o' threads on modding these on DIYAudio that had some good advice on squeezing every last molecule out of them.

I've always been a little unclear on bridged amps. I know one of the channels is inverted, and functionally on a circuit diagram I know how it all works. But in implementation it gets fuzzy for me...

- if playing in regular stereo mode, one of the channels is still going to be inverted correct?

- if using it in bridged mode, am I supposed to feed a mono signal to the inputs?

- I know I can't connect the "grounds" of the two channels since they technically aren't grounds, but in bridged mode the two unused one are sort of the "grounds" right? even if they aren't technically tied to true ground, but they should be close... I think I could theoretically tie them together with a pair of resistors?  Ugh this is messy in writing

Assuming:

A = L+

B = L-

C = R+

D = R-

and saying in bridged mode we connect the speaker to A&D, so let's say that D is the inverted one

that leaves B&C which in non-bridged mode are the grounds of their respective speakers right? So maybe not truly tied to the real ground, but they should be close-ish? Could I tie a resistor off each of those to make a common output ground? Though I know it'll bork my output impedance. I'm pretty sure I saw something similar to this from Jan Meier at some point.

Quote:

Originally Posted by Armaegis 

 

Going balanced lies madness I tell you! Thankfully I don't have any "proper" balanced gear, just speaker rigs hooked up to a 4-pin XLR.

 

 

 

 

 

I've always been a little unclear on bridged amps. I know one of the channels is inverted, and functionally on a circuit diagram I know how it all works. But in implementation it gets fuzzy for me...

- if playing in regular stereo mode, one of the channels is still going to be inverted correct?

- if using it in bridged mode, am I supposed to feed a mono signal to the inputs?

- I know I can't connect the "grounds" of the two channels since they technically aren't grounds, but in bridged mode the two unused one are sort of the "grounds" right? even if they aren't technically tied to true ground, but they should be close... I think I could theoretically tie them together with a pair of resistors?  Ugh this is messy in writing

 

Assuming:

A = L+

B = L-

C = R+

D = R-

and saying in bridged mode we connect the speaker to A&D, so let's say that D is the inverted one

that leaves B&C which in non-bridged mode are the grounds of their respective speakers right? So maybe not truly tied to the real ground, but they should be close-ish? Could I tie a resistor off each of those to make a common output ground? Though I know it'll bork my output impedance. I'm pretty sure I saw something similar to this from Jan Meier at some point.

It wasn't all that unclear to me until I hit this post

I think the problem lies in different types of bridging. I'm sure I'll get this wrong in print so I would urge a search over at DIY Audio, they have pictures and everything:)

Bridging to mono requires one channel input to each amp so yes it is mono. Which is how it all came about in the first place when there was no stereo equipment and folks had a lot of mono in stock and at home.

Where this can get really nasty is when a chip like the ta2020 is internally bridged. Some chips are common ground some are not. This one is not.

In your a b c d  note that should be right (Athough Im not totally sure we havent hit some perverse Haffler effect here). There was a post on the Digikey or mouser  site where one guy responded to using the 2020 as a headphone amp by using a 1kohm resistor (I think????) he claimed that solved the grounding issue. I am not convinced and have not tried that myself. The possibility of cooking the amp and whatever is attached is too high for my liking.

On another note the 2022 can be bridged and therefore makes a better candidate for pushing headphones. I am still pondering using one for the Fostex and YH3's.

Here is a link showing the basics.

http://www.41hz.com/forums/content.php?288-Bridging-the-TA2022