GB300D Kit Build

audiojerry · « **Reply #20 on:** 23 Mar 2006, 01:10 pm »

Thanks for sharing, Kle
Anyone else able to share yet?

KLe · « **Reply #21 on:** 24 Mar 2006, 07:09 am »

Quote from: KLe

Hi all
Thought that you might like this image http://www.diyaudio.com/forums/showthread.php?s=&postid=875976#post875976
This amp was a Metaxas Solitare, but, now it's a Metaxas GB300D

mgalusha, just wondering how your GB300D is going

Hi all
I believe that it is easier to view the image at this url ...
http://www.diyhifi.org/forums/viewtopic.php?p=9000#9000

Thanks audiojerry

amplifierguru · « **Reply #22 on:** 24 Mar 2006, 08:44 pm »

Hi KLE,

And here's another GB300D, from Germany, with 2 x SMPS -

http://www.diyhifi.org/forums/viewtopic.php?p=9059#9059

Cheers,
greg

mgalusha · « **Reply #23 on:** 25 Mar 2006, 05:31 pm »

I'm hoping to get back to mine. The boards have been done for a couple of weeks now but a few things have conspired to keep me from working on them. Too cold to fire up the machines in the garage to drill the heatsinks last week and surgery on one eye this week. I'm hopeful for tomorrow.

amplifierguru · « **Reply #24 on:** 1 Apr 2006, 06:32 am »

Hi Mike,

How's the amp build progressing?

Here's another GB300D monoblock conversion -

http://www.diyhifi.org/forums/viewtopic.php?p=9443#9443

Lovely open spacious chassis to work on.

Cheers,
Greg

mgalusha · « **Reply #25 on:** 17 Apr 2006, 02:31 pm »

Woohoo! I finally had enough time to finsh assembling the amps.

I completed the first one on Saturday and the other last night. Other than neglecting to install a link for R28 they fired up without any problems.

I let them play overnight and when I went into the basement this morning they were still playing, always a good sign.

They were running right at 101 *F, so it appears the thermal sensing transistors and heatsinks are doing their job.

They seem to be very quiet and I didn't have any hum, buzzes or anything else. I did listen to a few tracks this morning and they seem to sound good but I need to get them into my main system to get a better handle on them.

I'll try to get some photos posted tonight.

amplifierguru · « **Reply #26 on:** 17 Apr 2006, 09:42 pm »

Excellent progress Mike!

That's +15C for approx ~ 25W (assuming +/-60V rails) so about 0.6C/W

That's a comfy idle temp.

Look forward to your impressions, pics..

cheers,
greg

mgalusha · « **Reply #27 on:** 18 Apr 2006, 12:10 am »

A few photos. The amps are residing in some old Parasound HCA-1201 chassis. Certainly a good test of the PSRR as these only have 10,000uF per rail.

BradJudy · « **Reply #28 on:** 18 Apr 2006, 01:00 am »

Looks good Mike. I see you're using cablepods for binding posts. Do you like them?

Hogg · « **Reply #29 on:** 18 Apr 2006, 01:37 am »

Beautiful job, Mike. I can't wait to hear your comments on the sound.

Jim

mgalusha · « **Reply #30 on:** 18 Apr 2006, 03:41 am »

Quote from: BradJudy

I see you're using cablepods for binding posts. Do you like them?

Brad,

I do like them but their use was serendipitous. I couldn't find the the original posts that were on the amps and I needed a set. I gave Wayne at Bolder Cables a call to see if he had any he might be able to spare. His business isn't selling parts but he did have a set of the Cable Pods he could part with.

As you might notice in the photo the posts are mounted on a small aluminum plate. The chassis had a large oval hole and standard posts had nothing to bolt to. The original posts attached using screws where the plates are now bolted on.

Kind a long winded explanation but yup, I do like the cable pods. I don't know if they affect the sound in any way but I do like the way the operate in that the contacts don't rotate so spade lugs don't try and twist.

mgalusha · « **Reply #31 on:** 18 Apr 2006, 03:44 am »

Quote from: Hogg

Beautiful job, Mike. I can't wait to hear your comments on the sound.

Jim

Thanks for the kind words Jim. They've been playing for about 24 hours and I plan to let them run in for a few more days, touch up the bias if needed and then sit down and see how they sound in my main rig. That system has a pair of R.E. Designs LNPA 150's which are the best SS amps I've ever owned, so it will be interesting to see how the SKA's compare.

Mike

Gordy · « **Reply #32 on:** 18 Apr 2006, 03:47 am »

Quote from: mgalusha

Brad,

I do like them but their use was serendipitous... but yup, I do like the cable pods. I don't know if they affect the sound in any way but I do like the way the operate in that the contacts don't rotate so spade lugs don't try and twist ...

I like that idea! A shame all posts aren't built that way....

KLe · « **Reply #33 on:** 18 Apr 2006, 11:32 am »

Hi mgalusha
Well done, indeed, with the build

I've called it a Parasound GB300D (high current, absolutely).

Yes Gordy, the posts are very nice, aren't they

Mike, I look forward to your listening impressions

cheers

mgalusha · « **Reply #34 on:** 18 Apr 2006, 01:49 pm »

Thanks KLe. It's actually the second time I've used this chassis with new boards. The first time was as a home for a set of the LC Audio ZapPulse class D amps.

I can say for sure that the SKA's are much more agreeable that the ZAP's were.

JoshK · « **Reply #35 on:** 18 Apr 2006, 03:14 pm »

I wish I had some nice chasses like that to use.

amplifierguru · « **Reply #36 on:** 18 Apr 2006, 11:30 pm »

Hi Mike,

Nice open chassis, that! Good for surgery.

Just a suggestion - is it possible to re-route the blk/wht power switch wiring around the outside of the PS C's rather than close to the module input region? They radiate the primary charging spike currents.

I'd be tempted to have a nice perf-metal cover made for these to increase ventilation over that internal heatsink. You know the material a lot of tube amps have where the inside is half visible with 4-6mm holes.

Better see if the sound justifies it first.

cheers,
greg

amplifierguru · « **Reply #37 on:** 19 Apr 2006, 07:40 am »

Hi Mike,

...."Just a suggestion - is it possible to re-route the blk/wht power switch wiring around the outside of the PS C's rather than close to the module input region? They radiate the primary charging spike currents. "

probably really no need if there's no hum or buzz... just me being n th degree!

I'm sure the vents are adequate - I'm just going thru a perf-metal phase.
It may pass.

Cheers,
Greg

KLe · « **Reply #38 on:** 22 Apr 2006, 10:56 am »

Quote from: mgalusha

Thanks KLe. It's actually the second time I've used this chassis with new boards. The first time was as a home for a set of the LC Audio ZapPulse class D amps.

I can say for sure that the SKA's are much more agreeable that the ZAP's were.

Hi mgalusha
What LC Audio ZapPulse class D amps did you use

What did you find were their main weakness(s)

mgalusha · « **Reply #39 on:** 22 Apr 2006, 11:54 am »

KLe,

I used the Zappulse 2.1 SE modules. They actually sounded pretty good in my HT system. The problem what the Zin was only 2K and I was running a tube preamp at the time. It's Zout was about 600 ohms and they were not a good match at all. I neglected to find out he Zin before ordering the modules, assuming it would be something more "normal".

I did get some instructions on how to change this but I never got around to it and eventually sold the modules.

Mike