[haymaker18]

Quote:

Originally Posted by brainsalad /img/forum/go_quote.gif PPkiller - or anybody - When I go to Newark and search on ad743 I get 6 different selections. How do I know which one is the right one? Same thing with the LMH6655. What are the differences?

When I checked on Newark, they were all 16-pin versions. I wanted the 8 pin DIP version (I think it's laid out exactly like the AD797...a single channel opamp--so you need two for L/R--but someone correct me if I'm wrong). I got them from a user on head-fi but he doesn't have any more for sale. You could always go to Analog Devices website for more information: Analog Devices AD743 - Ultralow Noise BiFET Op Amp

I think, as a last resort, you could even buy them direct from the manufacturer.

 

[brainsalad]

Haymaker, I followed your link to Analog Devices, they show a JN and JNZ. What does the "Z" delineation indicate?

I found both versions on Quest.com, but it's interesting when you order it, the Z version brings up different manufacturers but the non Z version is from Analog Devices.

I have found this type of delineation differences, not necessarily the Z, on virtually every OP amp I have looked up.

As you can tell, a newbie but eager to learn.

 

[haymaker18]

I think I would go with the JN instead of the JNZ but I really don't know the difference. For the AD797s, there are both AN and ANZ versions of the DIP setup...I got the AN and it works great. I think it's more common and readily available.

I'm sure someone else will know more about the specific differences, but you'll be fine with the JN.

 

[haymaker18]

Also, with the AD743 or the AD797, don't forget you'll need a single to dual browndog adapter. Hiflight can steer you towards the right adapter, as it can be confusing on their website (at least for me). Since both are single channel opamps, you have to use two of them (one for each of the L/R channels) and put them onto the adapter to fit into the 8-pin socket on your iBasso.

Hiflight sent me an already soldered single-to-dual browndog adapter and a set of bypassed buffers for my opamp rolling--very helpful since I had no clue what I was doing. It was only a few bucks and infinitely helpful. Now, I'm starting to get the hang of it on my own!

Also, another thing I didn't know: if you are rolling the buffers and soldering your own, when you get a browndog soic-to-dip adapter, it won't quite fit in the tight confines of the space around the buffer. You can grind off some of the edge of the adapter, but to be comfortable, you should get a DIP socket from Radioshack. They are like $.59 for a two-pack. They're just an 8-pin black socket that you slide the adapter into--like an extension. They should help you clear the battery and any other things that get in the way.

Also, for my soldering, I found .022 diameter Silver solder (62/36/2%) that I like very much for the soldering. A #6 soldering tip worked well in the narrow confines of the opamp soldering. Also, I found a big container of flux there at Radioshack for cleaning the board before soldering

 

[brainsalad]

What??? I have to get a soldering iron?? I was going to use my propane torch I use to solder copper tubing and a solder bar.

I just ordered the Weller WM120 Weller Soldering Irons,

I will get some of the .022 solder and flux. Thanks for the tip.

 

[jamato8]

Just remember to solder hot and fast. You do not want to leave the tip in place but a few seconds so a hot tip will get the job done fast and heat up the rest of the component less, which is what you want. I use a 25 watt with a very fine tip and for wire connections I use a larger tip. The 25 watt will work on smd's and on larger surfaces. It is all in the light touch. I also use a magnifying lens to check solder points as it is easy to have a touch of solder link to another trace or pin with these small smd's.

Great fun once you get going.

 

[haymaker18]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif Just remember to solder hot and fast. You do not want to leave the tip in place but a few seconds so a hot tip will get the job done fast and heat up the rest of the component less, which is what you want. I use a 25 watt with a very fine tip and for wire connections I use a larger tip. The 25 watt will work on smd's and on larger surfaces. It is all in the light touch. I also use a magnifying lens to check solder points as it is easy to have a touch of solder link to another trace or pin with these small smd's. Great fun once you get going.

Yes, it's certainly easy to make a mistake! I haven't done this much...is it possible to have one faulty solder out of the 8 and still get sound out through it? Is there any way to KNOW you did it totally correctly? I'm hoping it's the kind of thing that it either works or it doesn't. My solders look good so far, but I like to panic about these things...

 

[jamato8]

Just have fun. I use a magnifying glass to look at each leg to make sure that the solder has melted correctly. If there is no connection then that is called a cold solder. In a few cases a chip would still work "if" that pin was not actually used as in some single opamps but normally the chip would not work. Just check the solder joint closely and make sure you have pin one of the opamp where it should be on the adapter board. Pin one will have a small mark like a detent in the plastic, or the corner of the opamp where pin one is will be slightly squared. You can always go to the manufactures spec sheet and see how they mark pin one but most of the time, with a magnifier in some cases, you can see where 1 is and match it up. Everyone will get the hang of it with some experimentation. Just make sure that you don't jump the traces with solder or you could short something an there goes your amp. Just take your time, look at what was done and enjoy.

I also will use a meter to check continuity at times.

 

[wolfen68]

I've been trying to keep up with this group's efforts with the D1, but this thread has gotten quite daunting (even with the helpful first page updates)

If I buy a D1 today, am I understanding correctly that it would be a new/improved version with updated opamps/buffers? The website isn't real clear on this.

If so, how does the 'new' D1 do as compared to other portable amps...or maybe most important to me, how does the D1's DAC do as compared to other small DAC's (such as the MicroDAC)?

 

[jamato8]

Well with HiFlight's last post he infers that the D1 amps sound very good. I will add that the dac section does a fine job. It isn't be best but in its price range, and I think in a range of hundreds more, it does very well. For all of the abilities of the D1, I still think it is a great buy and will be for some time. The current D1 has a very good charging chip, has the new opamps that sound better and appears to have few problems and produces good music.

HiFlight has a good dac to compare for further comments.

 

[musicmaker]

I agree. Overall I think the D1 represents incredible value for money. The D1's DAC is its strong suit. The amp is decent IMO but the dac is great especially given the price. The battery life is very good considering everything the D1 does. So you get a great product, for a great price backed by a company that takes customer service very seriously.

I've also purchased a HR microdac as I've been wanting to compare for while. Should be arriving shortly.

I know HiFlight has the HR ultradac, had done way more D1 opamp rolling that I have and can comment on how the D1 stacks up.


Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif Well with HiFlight's last post he infers that the D1 amps sound very good. I will add that the dac section does a fine job. It isn't be best but in its price range, and I think in a range of hundreds more, it does very well. For all of the abilities of the D1, I still think it is a great buy and will be for some time. The current D1 has a very good charging chip, has the new opamps that sound better and appears to have few problems and produces good music. HiFlight has a good dac to compare for further comments.

 

[souperman]

Now I can't wait for the D2

.

 

[jamato8]

It should be good. Everything learned from the D1 and the ongoing R&D that never stops. The small size should make for a nice package.

 

[kiwirugby]

If my memory serves me well, and John, Ron and others correct me if I am wrong, the D2 will only have a USB optical in, where as the D1 has USB and toslink in. Nothing wrong with that. It all depends on your sources.

Ron (HiFlight) helped me with the following opamp rolling.

L&R: AD746
Buffer: LME49720
DAC: LT6234

I am sure Ron has experimented more since he did this before the holidays.

I am now using the following: Sony D-EJ2000-->Sysconcept toslink-->D1-->P2-->AKG501 or ESW9 for classical and some jazz.

Sounds fantastic to me!

 

[jamato8]

Yes, the D2 will have USB only. The D1 with all of its multiple options is the only unit on the market like this that is portable and packable.