hotaudio40 's amps
Mar 4, 2009 at 3:44 AM Post #421 of 771
Quote:

Originally Posted by hotaudio40 /img/forum/go_quote.gif
Yes, I do that all the time, but I find going to a 3.5mm to RCA splitter first and then to some nice RCA cables works better.

Like those Y type adaptors.
One solid piece.
3.5mm in, two RCAs out.

Like this:
3.5mm Stereo Headphone Jack to 2 RCA Splitter Adapter - eBay (item 140289725537 end time Mar-17-09 06:20:13 PDT)

Then to some nice RCA cables.




Ok cool beans, I'm going to try one out I think. Gotta see where the money is though (damn being broke).
 
Mar 4, 2009 at 9:29 PM Post #423 of 771
Quote:

Originally Posted by rx7mark /img/forum/go_quote.gif
I got mine here: iPower PRO Rechargeable 9V Lithium Polymer Battery 520mAh


Wow, that is one serious battery. It makes me wonder about two things:

Does the Raging Moose sound any better with that extra current on tap? My 280s last long enough that I'm never out of batteries, and with the additional cost of a charger and 2 batteries...

That makes me want a desktop version of the Moose. That's an additional $70 on top of the amp itself. At that point it might be more economical to have a wallwart option, at least.
 
Mar 4, 2009 at 10:16 PM Post #424 of 771
Hmmm... Yes, a wallwart version would be cheaper.
And as you said, same here, my 280 mAh batteries work very well.

But look at that battery....

Technically the amp WOULD sound better with more current as it sounds very good with the 280mAh NiMH batteries.

It would have a more solid bottom end and of course more powerful sound with the 550mAh battery.

But it would be cheaper to add the internal regulator and include the wallwart adapter.

That design is in the books for sure...
 
Mar 5, 2009 at 3:07 AM Post #425 of 771
Quote:

Originally Posted by hotaudio40 /img/forum/go_quote.gif
Hmmm... Yes, a wallwart version would be cheaper.

But it would be cheaper to add the internal regulator and include the wallwart adapter.

That design is in the books for sure...



...and will that design sit on a desk and have little feet? Will it be a amp/DAC combo with multiple inputs and RCA outs? Just wondering...
 
Mar 5, 2009 at 3:37 AM Post #426 of 771
Quote:

Originally Posted by lowlevelowl /img/forum/go_quote.gif
That setup should work great. You will need a 1/8" mini jack to RCA cable. To connect the DAC to the AMP. I just ordered one from Blue Jeans Cable for under $30. Haven't received yet, so I can't comment on quality, but others here seem pleased with it.


I have one of the blue jeans cables mini to rca's and I have been very pleased with it. Build quality is good and sound quality is even better.
 
Mar 5, 2009 at 4:23 AM Post #427 of 771
Quote:

Originally Posted by ddoingwell /img/forum/go_quote.gif
...and will that design sit on a desk and have little feet? Will it be a amp/DAC combo with multiple inputs and RCA outs? Just wondering...


lol, I have so many "little feet" around, I used to buy feet for the amplifiers I used to make a long time ago, so I have tonnes of "little black rubber feet"
smily_headphones1.gif


Even some clear ones now.

And tonnes of everything else needed to make such a unit...

I was thinking one set of RCA inputs to feed the preamp stage.
One set of preamp outputs, for output of course.

A built in USB DAC of course.

A switch to switch between the DAC or the RCA inputs to feed through the preamp stage.

A headphone jack or two of course
smily_headphones1.gif


Maybe a switch for "DIRECT OUT" of the DAC to the output RCAs.

And maybe one of those fancy digital volume controls with "UP" and "DOWN" volume buttons, but I think the first model will just use the standard analogue volume control.

It will run off a standard wallwart AC power adaptor, as I've made several preamps / headphone amps with them already... back in the day... lol...

And I would love to incorporate a LM3886 power amplifier , but of course it would be fed from a separate power supply not included in the unit.

I prefer to run the LM3886 off of batteries anyways... So there would be an input for the +/- 12 Volts or so to run the power amp.

That is my dream machine so far and it will come in a metal case of course for the heat-sink for the power amp stage.

But the first model WON"T have the power amp stage, just the DAC and preamp.

Maybe two sets of input RCAs and a switch to control them....

All of that is doable and I've done it before as well... just have never sold any units like that.

I used to sell AC powered headphones amps, like I said, way back in the day... lol

And I even sold Power amplifier kits, but those were not too profitable...

Power supplies are very pricey... Never mind shipping those heavy units...

There are even a bunch of "CLASS D" power amp chip out now that run near 95% efficiency...

Unbelievably they will drive speakers up to almost 3 watts into 8 or 4 ohms off of a 5 Volt power bus.

Some even go as high as 25 Watts using 12 Volts and the chips don't even require heat sinks and are the size of dimes...

I kid you not...

I've played with a few of those chips and it blew me away that they didn't even get warm....

They didn't sound too good either, lol, but I am new at the "CLASS D" game...

That fact is that they DID work though!

I could throw one of those in as a beginner amp for "easy listening" at low levels...

Lots of ideas....
 
Mar 8, 2009 at 3:12 AM Post #428 of 771
Just got my Mark VII, which takes almost the whole week all the way to my rural town. Immediately, I tried it out with my FLAC files in my PC and HD555 and compare it with same FLAC files on Sanasa Clip.

After a few vocal oriented music (Amanda's Dreaming), I did not find much difference. My ears have been deteriorated by portable MP3 player and PX100 for too long, I guess. The worst thing was that I heard quite a bit noise when I turned the volume control knob. (No noise at all when it is not turned) What? I though this only happens after many years of use. But this suppose to be a brand new device!!

So I did some digging at head-fi forum and found quite a few people complaining about noisy volume control pot. The most interesting thread is the one discussing HeadRoom's Airhead. (sorry, I lost track on that link.) It seems that there is a tradeoff between whether some close DC component gets filtered out or not. Without additional filtering, the sound quality is better but noise from volume control may be heard.

I contacted Dave and mentioned my concern. He immediately replied me with this mail:

I was wandering when somebody was going to ask that guestion...

The pot is NEW and a very good one.

What you are hearing is the contact movement of the brush on the potentiometer.

Now normally you would NOT hear this noise because most commercial amps don't go below 20 Hertz.

I make my amplifiers go sub-sonic, well below 20 Hertz, almost to DC or Zero Hertz.

That's why you hear the potentiometer noise.

You would hear it with ANY potentiometer if the device you were using went down that low, but they don't.... probably because of that exact reason, you can hear the pot move...

But I like to give a fuller spectrum of sound.

In fact I give the FULLEST POSSIBLE spectrum of sound possible.

You can't get that level of fidelity and sonic detail UNLESS you go lower then 20 HERTZ.

So what you've got is an exceptional amplifier, capable of hearing even the sound of the potentiometer moving....

Think about that for a while....

You should for sure hear more detail in the bottom end, wait till it burns in a while...

Dave.


I have say that I felt much better after receiving such confirmation. Still I wonder if doing some spraying of contact cleaner would help (or no use in this case?)

After less than 12 hours of burn-in and trying some more demanding music (Antarctica soundtrack and Enya's Watermark), my ear starts to hear the difference better. My first impression is that the sound stage is much wider comparing to Clip's. Also, the body of sound is fuller and smoother. With louder volume, Clip's sound quickly becomes tiring but I can keep enjoy Mark VII's sound. (I usually set volume between 11~12 o'clock.) Clip also sounds like being shaped by certain EQ setting (actually none used) and Mark VII sounds very open and fills all the spaces.

Then Enya's Watermark really shows that Mark VII give tighter mid bass. And I start to feel a little bit low bass which was absect in Clip's sound. The impact or the amount of bass was not increased much, but the quality and extension are definitely improved.

Overall, I am quite pleased with Mark VII. Since I don't have other nice setup to compare at this moment so this report is kind of limited. I'll try to see the improvement on the vocal, which is also my favorite. Also, a used DT 880 is coming and hopefully that will allow me to appreciate Mark VII more.
 
Mar 8, 2009 at 7:40 PM Post #429 of 771
You know how you never miss something until it's not there? Well, I'm sitting on my porch (it's nice out, finally) and reading. I decided to be lazy and just grab my 2200s--no USB1, no amp.

And my ears are bleeding. Well, not it's not quite that bad, and these phones can actually sound halfway decent without an amp...but that USB1 is a godsend. I'm getting all kinds of distortion--not even internal noise (though that's there--mostly in the every single part of the range of human hearing.

I don't mean to harp on just how bad the D630 headphone out is...but it's the first time I'm using it for music since I did some A/B testing when I got the USB1. And I can say that with a solid 2 months of use that I couldn't imagine going back. The differences are night and day.

Well, back to my book.
 
Mar 8, 2009 at 8:28 PM Post #430 of 771
I hate to be the guy who double posts, but oh well.

It got too windy outside, so I went inside and thought, "I should get that dac straight I was thinking about." I know, that's a perfectly reasonable train of thought. So now there's one on the way--I'm interested to see if my ears will be able to tell the differences between the USB1 and the dac straight.

Either way, having a second dac should be nice. The dac straight for the EF1/home setup, the USB1 to travel with my laptop.
 
Mar 9, 2009 at 3:23 PM Post #432 of 771
I bought the DAC DESTROYER yesterday, and it was shipped just in couple of hours later. Amazing service, thank you hotaudio40.
I'm really looking forward to listen how it sounds, for now i have to listen music throught crappy onboard soundcard.
 
Mar 9, 2009 at 4:43 PM Post #433 of 771
I'm having a little problem with my HOTUSB1.

It makes a really irritating buzzing noise via my little dot I+ when i use it as a DAC for my PC. Using my AD900s right out of the DAC is fine and the little dot I+ works perfectly out of the line out on my Creative Zen, hell it even sounds good via onboard out.

Could it be the HOTUSB1 is incompatible with tubes or does the issue lie elsewhere?
 
Mar 9, 2009 at 5:02 PM Post #434 of 771
The USB1 works fine with my EF1--so it's not a tube hybrid issue. In fact, the USB1 -> EF1 is dead silent with the W1000s (the most sensitive cans I have to test with, they hum slightly out of the Raging Moose).

Are you using the same patch to connect the LD I+ to the USB1 as you are the LD I+ to Zen? If they're different it could be a cable issue.

Do you have any other amps to test with the USB1? Maybe there is a problem with it that you need an amp to hear--while that's not likely, it's possible.
 

Users who are viewing this thread

Back
Top