$175 Class D amp--120 wpc

avionic · « **Reply #140 on:** 29 Jan 2010, 04:31 am »

Quote from: Nick77 on 28 Jan 2010, 09:41 pm

I grabed these photos from a guy over at diy and he said it was a real pita swapping the caps as i suspected. My soldering skills were tested by just getting this up and running. Its a small board to work on and the sound i have now is pretty amazing. I might wait for a few more reports till i jump on this.

This looks real similar to how my board looks after installing the output caps. Only mine are audience auricaps. I also found it easiest to mount 2 on top and 2 on bottom. These amps are really easy to put together. The only thing that seems to give folks some trouble is the wiring of the transfo, which has been discussed in this thread. As mentioned already these amps sound great and probably even better because you put it together

Mariusz · « **Reply #141 on:** 29 Jan 2010, 05:00 pm »

Here is the answer from Tom regarding battery power supply:

" This is a very high power amp, so in order to run it from a battery, you
would have to use one of our 12V DC power supplies that we make for car and
marine use. You will still need a powerful batteries as the amps need allot of
current. Also, this power supply is only for the 250W X 2 500W X 1 amp."

I also asked about integrating volume pot and touched on overheating concerns.

Overall good communication and fast response indicated top notch costumer service.

Best
Mariusz

6SN7 · « **Reply #142 on:** 29 Jan 2010, 07:58 pm »

I haven't posted here for a long time, but I thought I'd jump in since I was made aware of Class D Audio's products at the same time as Steve K, and I too am a proud owner of their amps. I say amps, plural, as I purchased two of the 60w x 2 into 8 ohms with upgraded power supply, and I'm running them bridged, as mono blocs.

I find it interesting that Tom is developing a higher performance heat sink for these amps so they will be better suited for 4 ohm loads, as I'm running mine into Magnepan MG12s, which are rated at 4 ohms, and although I don't usually play at very high spls, my heatsinks barely get warm at all. My amps are stock, but I did have Tom adjust the gain to 26 db when I placed my order. And for the record, I'm using a tubed preamp.

I am making good progress on making enclosures and will share photos soon. The fact that I am spending the time to make enclosures is indicative of how I feel about these amps--not only are the breadboards soon to be history, so are the tube mono blocs I have been running full range and enjoying for eight years. As much as I enjoyed my tube amps (even my moniker reflects that), I just can't say enough good things about Tom's amps. As Steve mentioned, soundstage depth isn't quite as good as with the tubes, but everything else is just excellent. I didn't know my speakers were capable of this kind of bass, and the etch-free detail I now hear consistently evokes the words "oh my", even at very low volumes. This has been an enormous step in the search for "real" sound.

Both Steve and I were initially skeptics, and now, after reassuring each other that we weren't deceiving ourselves, it's great to see others discovering such an inexpensive path to audio enjoyment.
Bob

Nick77 · « **Reply #143 on:** 29 Jan 2010, 08:23 pm »

Quote

I didn't know my speakers were capable of this kind of bass, and the etch-free detail I now hear consistently evokes the words "oh my", even at very low volumes.

I am having the same reaction, i didnt know my speakers were capable of such awesome bass.

nodiak · « **Reply #144 on:** 29 Jan 2010, 10:26 pm »

I'm Interested in anyone's experience with adding volume pot to the 250 x 2 amp. What impedance value mates well, and wiring pics or diagram if possible.
I have one ordered and would like to be able to use it as integrated, as well as adjust gain for use with preamp. I had Tom reduce gain to 26db as others have.
My speakers are 2 ways with a 12 sealed with a small widerange on ob.
These sound like nice amps.
Really appreciate this thread.
Don

jtwrace · « **Reply #145 on:** 29 Jan 2010, 11:10 pm »

why are you guys adjusting the gain?

Steidl Guitars · « **Reply #146 on:** 29 Jan 2010, 11:17 pm »

Quote from: jtwrace on 29 Jan 2010, 11:10 pm

why are you guys adjusting the gain?

I'm no expert, but here's what I've gathered....

26 db is pretty standard if you have an active preamp; if you have a passive preamp of some sort, extra gain is helpful. With a high gain amp, lots of active preamps would only be able to use a narrow range of theei volume control.

steve k · « **Reply #147 on:** 29 Jan 2010, 11:18 pm »

Quote

why are you guys adjusting the gain?

Because 26 dB gain is more typical for amp gain in the industry. Higher gain might produce more noise in the signal and give you less control over the volume with your preamp.

jtwrace · « **Reply #148 on:** 29 Jan 2010, 11:20 pm »

What is the gain if you don't ask for a change (which I didn't)?

steve k · « **Reply #149 on:** 29 Jan 2010, 11:30 pm »

32 dB

Nick77 · « **Reply #150 on:** 29 Jan 2010, 11:31 pm »

I didnt ask about it either but it performs flawlessly with the pre-outs on my HK.

jtwrace · « **Reply #151 on:** 29 Jan 2010, 11:32 pm »

hmm. Wonder if I'm screwed. I use a tube buffer.

gld · « **Reply #152 on:** 29 Jan 2010, 11:38 pm »

Jason, your fine with the gain at 32db. I have had one of the 250Wx2 @4ohms for awhile now and I haven't said anything because I am doing something different with mine. I'll be letting everyone know when I am finished with it. Let me say though that even totally stock these things are wonderful!!

Gary

jtwrace · « **Reply #153 on:** 29 Jan 2010, 11:41 pm »

Quote from: gld on 29 Jan 2010, 11:38 pm

Jason, your fine with the gain at 32db. I have had one of the 250Wx2 @4ohms for awhile now and I haven't said anything because I am doing something different with mine. I'll be letting everyone know when I am finished with it. Let me say though that even totally stock these things are wonderful!!
Gary

WooHoo! Now that's service...from the maker of my tube buffer. Gary Dodd. Can't wait to see what you're doing with yours.

Steidl Guitars · « **Reply #154 on:** 29 Jan 2010, 11:42 pm »

That's high praise from you Gary, and nice of you to offer up.

avionic · « **Reply #155 on:** 30 Jan 2010, 04:38 am »

Quote from: nodiak on 29 Jan 2010, 10:26 pm

Interested in any experience with adding volume pot to the 250 x 2 amp. What impedance value mates well, and wiring pics or diagram if possible.
I have one ordered and would like to be able to use it as integrated, as well as adjust gain for use with preamp. I had Tom reduce gain to 26db as others have.
My speakers are 2 ways with a 12 sealed with a small widerange on ob.
These sound like nice amps.
Don

I am running a passive pre with a 10k pot and it works great.

OzarkTom · « **Reply #156 on:** 30 Jan 2010, 03:11 pm »

Quote from: Steidl Guitars on 29 Jan 2010, 03:31 am

You don't need a case, but it's a good idea. Several possibilities were offered earlier in the thread. This seems like a nice option:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250501444095

From that Ebay ad I went to their website. Just in case someone needs some extra money as a sideline business, you can go here and buy these cases on a wholesale basis. I just wish I knew what you guys were doing, I would go for it myself. But since I don't, I would buy one already mounted in a case.

You can get big discounts if you buy these cases in bulk.

http://par-metal.com/price.php

jtwrace · « **Reply #157 on:** 30 Jan 2010, 03:33 pm »

It took me about an hour of time to get it to this point. This is the 600w version. Considering this cost ($240) to my door and my 300w Class A amps cost $14k, this is scary.

I need more time to listen but out of the gate, it sounds really good.

I will post more pictures when I complete my aluminum case for it.

OzarkTom · « **Reply #158 on:** 30 Jan 2010, 03:56 pm »

Thanks for the pictures jtwrace. If I can see all the details, and yours gave me plenty of clues, I just will probably try it myself. The circuits of these amps looks so simple, that could be the reason for such great sound.

Less parts=better sound. I have believed in that philosophy for over 30 years.

If you look closely to the Channel Island's D100 mono amps for $1600 a pair, these circuits look very similar to those. And those amps never get bad reviews.

http://www.ciaudio.com/D100.html

steve k · « **Reply #159 on:** 30 Jan 2010, 04:01 pm »

Quote

It took me about an hour of time to get it to this point. This is the 600w version. Considering this cost ($240) to my door and my 300w Class A amps cost $14k, this is scary. I need more time to listen but out of the gate, it sounds really good.

Enjoy, my friend!!