[Chops]

Quote:

Originally Posted by Chops /img/forum/go_quote.gif Like I said, I have a pair of K701's and the sound from neither one of these amps is "thin and bright". And stock form ment just that, stock! Meaning that everything including the tubes. Just replacing the tubes will put the 708B over the top. If the LDM+ sounds thin and bright on your K501's but sounds perfectly fine on my K701's, then wouldn't you think it's NOT the amp? If your cans have no bass, it doesn't matter what amp you drive them with.

Man, I just re-read my last post. It sounds like I was pissed or something. I wasn't. Sorry if someone took it that way. I hope not.

 

[zer061zer0]

Well its ok dude.

Lets hope this helps to shift some attention from it ....hahhahaa~~~

The next upcoming madness for me

 

[Chops]

Quote:

Originally Posted by zer061zer0 /img/forum/go_quote.gif Well its ok dude. Lets hope this helps to shift some attention from it ....hahhahaa~~~ The next upcoming madness for me

That's a real nice little case! Rack handles and all, too!

I was thinking, if I were to put the 708B guts into a new case, I'd have the power transformer all the way back in the left rear corner, as far as possible from the driver and output tubes, and have the PS board up front. But that's just me.

 

[dcheming]

That's a pretty sweet little case! You've got plenty of room to play with now.

I'm with Chops in thinking that I would change the parts layout. It looks like the audio board would just fit sideways in that case. You could mount the audio board right up front and then mount the transformer and power supply in the very back. You could even fabricate a steel wall to isolate these two areas if you wanted to get fancy and if you put the power switch on the back you could keep all the AC-carrying parts/wire in that one area.

Well my 1/4-40 taps came in the mail today so I'll finally be able to finish mounting the source selector switch. Man, just seeing the 708B guts in zer061zer0's new case makes me want to do a re-case too!

So much energy, so little money.

 

[Chops]

Quote:

Originally Posted by dcheming /img/forum/go_quote.gif So much energy, so little money.

Yeah, I know the feeling all too well. However, I would have also added "so much time" to the list as well, at least in my case.

BTW Derek, I need you to get with me sometime at your convenience (of course) about locating and replacing ALL of the vital resistors in the signal chain, including the ones on the headphone jack.

Would changing the values of any of these be any good, or should they stay as is, just better quality? Depending on how many I'll need and their prices, I might try going with the Audio Notes or Vishays.

 

[zer061zer0]

Quote:

Originally Posted by dcheming /img/forum/go_quote.gif That's a pretty sweet little case! You've got plenty of room to play with now. I'm with Chops in thinking that I would change the parts layout. It looks like the audio board would just fit sideways in that case. You could mount the audio board right up front and then mount the transformer and power supply in the very back. You could even fabricate a steel wall to isolate these two areas if you wanted to get fancy and if you put the power switch on the back you could keep all the AC-carrying parts/wire in that one area. Well my 1/4-40 taps came in the mail today so I'll finally be able to finish mounting the source selector switch. Man, just seeing the 708B guts in zer061zer0's new case makes me want to do a re-case too! So much energy, so little money.

I wanted to have hat configuration with all the ac stuff at the back but the only worry is the trouble in switching it on and off. I have also gotten a noise filter iec and some ferrite to be mounted along the powersection.

Anyone any experience in cutting a hole for the iec.

 

[Chops]

Quote:

Originally Posted by zer061zer0 /img/forum/go_quote.gif I wanted to have hat configuration with all the ac stuff at the back but the only worry is the trouble in switching it on and off. I have also gotten a noise filter iec and some ferrite to be mounted along the powersection. Anyone any experience in cutting a hole for the iec.

I remember years ago on the old desktop AT computers with their AT power supplies, some of them had the power switch inside the PS itself. There would be a long metal bar (linkage) that ran all the way from the PS in the back of the computer up front to the actual power button on the front panel of the computer case.

Being that this amp is pretty close to being silent anyway, I don't think I would worry about having a couple of power wires coming up front to a switch on the front panel. I'd just have the switch all the way to one side and the wires crammed as far into the corner of the case as possible to keep them away from the audio board.


"Anyone any experience in cutting a hole for the iec?"

Maybe very carefully with a dremel?

You could draw the opening on the chassis, then take a drill with a small bit and drill along the line, then go through it very very carefully with the dremel, sliding to each drill hole, creating the entire opening for the IEC.

Of course, I'm sure there's most likely a better, easier way of doing this than what I said above.

Either way, good luck!

 

[dcheming]

Well I just finished up doing the switch mounting. It went smooth, but the only thing I'm not happy with is the finish on the chamfer for the tapped hole. The chamfer bit I used was less than ideal for aluminum so it didn't leave a very good finish. I'll have to get a better chamfer tool later and touch it up to give it a mirror finish. I also removed some of the wording on the front panel with alcohol to make it look cleaner. It took a little while to measure everything out to see if it would fit still, but the end result is that with the mounting hole exactly centered from the outer edge of the vol pot chamfer to the edge of the faceplate, the body of the switch itself rests directly on the chassis bottom so it will never rotate loose. Overall I'm happy with how it turned out.

 

[Chops]

Quote:

Originally Posted by dcheming /img/forum/go_quote.gif Well I just finished up doing the switch mounting. It went smooth, but the only thing I'm not happy with is the finish on the chamfer for the tapped hole. The chamfer bit I used was less than ideal for aluminum so it didn't leave a very good finish. I'll have to get a better chamfer tool later and touch it up to give it a mirror finish. I also removed some of the wording on the front panel with alcohol to make it look cleaner. It took a little while to measure everything out to see if it would fit still, but the end result is that with the mounting hole exactly centered from the outer edge of the vol pot chamfer to the edge of the faceplate, the body of the switch itself rests directly on the chassis bottom so it will never rotate loose. Overall I'm happy with how it turned out.

Talk about tight tolerances, and great work! WOW!

And there's nothing better than a few metal shavings embedded in the carpet.

Nice volume knob, too. Does that actually fit in the stock recess? Pretty slick.

 

[zer061zer0]

Impressive stuff if only i have those tools and skills.

 

[That dude]

Quote:

Originally Posted by zer061zer0 /img/forum/go_quote.gif Its such a pity, my amp is in 5 different parts, otherwise u can come to my place to try them out. I am also curious as to wat the mods have done to drive the akg501 better. My very first purchase was infact pondering btw the akg501 and the ms2i with the XS708B. If u can wait i might be able to have the amp up in a few weeks time and u can come over to my place to hear them with ur 501.

Haha, thks for the offer but no hurry, cause I live in Singapore.

Quote:

Originally Posted by Chops /img/forum/go_quote.gif Like I said, I have a pair of K701's and the sound from neither one of these amps is "thin and bright". And stock form ment just that, stock! Meaning that everything including the tubes. Just replacing the tubes will put the 708B over the top. If the LDM+ sounds thin and bright on your K501's but sounds perfectly fine on my K701's, then wouldn't you think it's NOT the amp? If your cans have no bass, it doesn't matter what amp you drive them with.

Well, the LDM+ is certainly not strong enough to drive the k501 to its fullest. I have tried them with everything I owned and i still felt they sounded "thin and bright" compared to my go-vibes or my desktop power amps. Moreover, "thin and bright" just suggest that the sound is fatiging. The k701 is a totally different animal, so you can't really compare.

I've tried it with the Diva tube amp (an amp from TS Lim in Singapore), and it made my k501 sing so smoothly and warmly... The X-tra X1 made the k501 into a hardcore rocker (really unexpected). In short, the amp plays a huge part, especially with such a picky headphone which is SOO difficult to drive.

Hey, thks for the input, I really appreciate it.

 

[zer061zer0]

Yeah that dude i know that u stay in Singapore, wouldn't have offer otherwise.

I have heard the x1 powering the k501, dont think its gd enough too. Maybe i am just picky...
Will pm u again when my amp is up.

 

[dcheming]

Thanks for the kind remarks guys!

"Anyone any experience in cutting a hole for the iec."

For my CD player I just drilled three 3/8" holes in the corners of the cutout and then used a little flat file to cut the rest. It took quite a while but it turned out pretty good. I wonder if someone makes a sheet metal punch just for doing IEC cutouts?

 

[zer061zer0]

I did a cut out of the iec on my cdp as well but wasnt very nice
Besides, the iec cut out on the cdp can be cut right from the top unlike the new case where i have to cut in the centre.

 

[Chops]

Speaking of cd players, I just ordered a brand spankin' new Music Hall CD-25.2 from Underwood HiFi at a more than excellent price! Thanks Walter! I'm also going to have him throw in 4 mirror imaged Burr Brown OPA-627 opamps to replace the inexpensive 2604 opamps in the stock unit.

I think this will be a substantial upgrade over my current cdp.