[rnd]

Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif I would not be at all concerned with the gain of the D1. I have found the factory gain setting to be perfectly adequate for all the phones I have tried, from the very efficient to very inefficient, from high-impedance to low-impedance.

My understanding is Grados and such need more current to maintain control and get all they are capable of - in particular with bass. Is this not true? I notice when I use an amp and set the volume high with the source low on the computer, the bass gets tighter and more pronounced in the very low registers. (It creates other problems because I'm amping an amped signal which is one of the reasons I'm looking for something like this) If this is true then I'm thinking a gain of 10 would mean I'd be using little current when the volume is at a reasonable listening level. Again I'm no expert with electronics so please forgive me if I'm misunderstanding this.

My headphones sound wonderful directly out of my source but I can tell there is more they can do if I could give them more current and avoid the problems with amping the amped signal I'm getting.

 

[nc8000]

Using the line in from my Sony the D1 only just has enough power to drive my K340's to acceptable (not loud) volume but going optical thru the dac there is plenty even for a monster like K340.

 

[jamato8]

That is amazing! I didn't think it would be able to drive those. Is it adequate in sound quality when driving the 340's or is there some authority with the sound?

 

[kiwirugby]

Off topic, so I'll be brief. I found my old Headroom airbag (eschewed for carrying an MP3 player+amp) and it sort of works for an iBasso and a pcdp (in my case a D-EJ2000). The iBasso sticks out the top section a bit, but with a short mini-Toslink everything is covered save for about 1.5 inches of the iBasso.

Just thought I'd share...I'm gald I could use it for this rig.

 

[DennyL]

There is much discussion of gain but not much discussion of the voltage output of the source. Gain is just (voltage output)/(voltage input). Although I haven't looked into this, isn't it the case that the voltage ouput of sources differs from one to another? Surely all CDPs and preamps don't output the same voltage??

I find that, driven by the optical output of my iRiver iH140, I have the volume of my D1 at about 12 o'clock with my AKG K701s and at about 2 o'clock with my Beyer D880s.

 

[sum1]

Quote:

Originally Posted by HiFlight /img/forum/go_quote.gif I would also suggest that the inexpensive Radio Shack DIP socket, part number 276-1995 which I use for mounting the DAC replacement opamp, be used with the buffers to simplify installation and removal. They only cost 69 cents per pair.

So is that Dip socket an alternative to the browndog adapter. If it is then can you please point me if one of these is similar to the radioshack one. I live in Australia and the closest we have to radioshack is a DSE store.

http://www.dse.com.au/cgi-bin/dse.st...uct/View/P4081
http://www.dse.com.au/cgi-bin/dse.st...uct/View/P4080

 

[souperman]

Quote:

Originally Posted by sum1 /img/forum/go_quote.gif So is that Dip socket an alternative to the browndog adapter. If it is then can you please point me if one of these is similar to the radioshack one. I live in Australia and the closest we have to radioshack is a DSE store. http://www.dse.com.au/cgi-bin/dse.st...uct/View/P4081 http://www.dse.com.au/cgi-bin/dse.st...uct/View/P4080

Those are exactly what Hiflight is talking about, but they are not an alternative to browndogs. SOIC amps need to be soldered and not just plugged in onto the brown dog adapters.

 

[HiFlight]

Quote:

Originally Posted by rnd /img/forum/go_quote.gif My understanding is Grados and such need more current to maintain control and get all they are capable of - in particular with bass. Is this not true? I notice when I use an amp and set the volume high with the source low on the computer, the bass gets tighter and more pronounced in the very low registers. (It creates other problems because I'm amping an amped signal which is one of the reasons I'm looking for something like this) If this is true then I'm thinking a gain of 10 would mean I'd be using little current when the volume is at a reasonable listening level. Again I'm no expert with electronics so please forgive me if I'm misunderstanding this. My headphones sound wonderful directly out of my source but I can tell there is more they can do if I could give them more current and avoid the problems with amping the amped signal I'm getting.

The current demand issue is one reason that I suggest the use of the AD8397 for buffer application. It is capable of outputting over 300ma of current, if required. That is about 10x the current output of most opamps not specifically designed for use as buffers.

There are quite a few opamps designed for buffer use, but the majority of those are single-channel rather than the dual-channel buffers required by the D1. Additionally, many of these buffers are designed for supply voltages greater than that supplied by the D1.

An additional requirement is the necessity of selecting a dual-channel, high current opamp that is able to be driven satisfactorily by the supply voltage provided to the buffers by the D1. Although the D1 uses a 12vdc power supply, the supply voltage delivered to the buffers is less than 6vdc.

Although may dual channel opamps will work as a buffer in the D1 with phones of modest current and voltage requirements, attention must be given to selection of an appropriate opamp with specific characteristics when use of headphones requiring high current levels is anticipated.

One would be surprised at the momentary peaks of current required during high-level transients, heavy bass levels, etc. Use of opamps incapable of delivering adequate current levels will compromise the accuracy of the sound delivered to the headphones, resulting in a lack of detail and loss of the sense of realism, especially in the bass frequencies.

 

[souperman]

Uh oh. I think I have a problem. While swapping opamps, a little gold thing came out of the socket that I was swapping opamps. It came up with the opamp and now I cant find this tiny tiny little gold piece piece. Now my left channel doesn't seem to be working anymore. What should I do?

 

[Skylab]

And that, Ladies and Gentlemen, is why I don't op-amp roll.

Soup, very sorry to hear about that. You're now missing one conductor receptical socket. You will have to have that repaired.

 

[souperman]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif And that, Ladies and Gentlemen, is why I don't op-amp roll. Soup, very sorry to hear about that. You're now missing one conductor receptical socket. You will have to have that repaired.

Actually, it works if I plug the opamp directly into the socket instead of going through a Radioshack socket that HiFlight suggested us use.

 

[Skylab]

So you only pulled the conductor out of the RS adapter then? Good.

 

[jamato8]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif And that, Ladies and Gentlemen, is why I don't op-amp roll. Soup, very sorry to hear about that. You're now missing one conductor receptical socket. You will have to have that repaired.

Sorry, I do not agree. It can happen to anything that has a removeable item. Ever break a light bulb when trying to unscrew it from the receptical? I have. I have also had problems at times with tube sockets but that is hardly a reason to not change tubes or is there a reason to not change opamps. Ever have a flat tire? No reason not to drive is it?

 

[souperman]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif Sorry, I do not agree. It can happen to anything that has a removeable item. Ever break a light bulb when trying to unscrew it from the receptical? I have. I have also had problems at times with tube sockets but that is hardly a reason to not change tubes or is there a reason to not change opamps. Ever have a flat tire? No reason not to drive is it?

Why is it that if I plug my opamp in directly, it works, but if I go throught he Radio shack adapter the left channel doesn't work anymore?

 

[souperman]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif So you only pulled the conductor out of the RS adapter then? Good.

No, I pulled the gold thing out of the adapter soldered onto the board. It's not the entire silver thing. It's just the gold little plug. It got stuck on one of my opamps for some reason, and I pulled it out, and it fell somewhere and I've been looking for an hour. Should I get this repaired? I mean I can just not use the Radio shack adapters for the LR channel and I'm fine with that.