$175 Class D amp--120 wpc

Nick77 · « **Reply #3340 on:** 8 Jun 2012, 01:28 pm »

Quote from: mboxler on 8 Jun 2012, 01:21 pm

What power cord did you settle on? (you may have stated this earlier, but...).

Thanks, Mike

Im using a wywire juice2 power cord with copper connectors. I will be auditioning a Triode Labs (seven plus) in a few weeks, they seem to be very popular.

maxitonus · « **Reply #3341 on:** 10 Jun 2012, 08:41 am »

To nick77:
Which are the exact references of 60kMicroF caps?(15k each?)and could they replace easily the original ones without modifying the board holes? thanX by advance fr ur reply.

Nick77 · « **Reply #3342 on:** 10 Jun 2012, 10:58 am »

Quote from: maxitonus on 10 Jun 2012, 08:41 am

To nick77:
Which are the exact references of 60kMicroF caps?(15k each?)and could they replace easily the original ones without modifying the board holes? thanX by advance fr ur reply.

Yes they fit the stock board, i used six of these Panasonic. Suppose to be a good bang for the buck. Always wanted to try the Mundorfs but couldn't find a cap to fit.

http://www.diycable.com/main/product_info.php?products_id=602

maxitonus · « **Reply #3343 on:** 11 Jun 2012, 08:17 am »

To Nick77:
Warm thanX,i will upgrade my caps.
In the same time, i will shorten the pots wires to the minimum possible,and put good input wires (silver or litz) and good speaker ones.
I will inform you after a strict comparison (before/ after mods),made in presence of a friend.

rajacat · « **Reply #3344 on:** 16 Jun 2012, 05:33 pm »

What distinguishes the difference between the SDS and the CDA series amps other than the larger heat sinks, balanced inputs and adjustable gain?

srb · « **Reply #3345 on:** 16 Jun 2012, 05:39 pm »

Quote from: rajacat on 16 Jun 2012, 05:33 pm

What distinguishes the difference between the SDS and the CDA series amps other than the larger heat sinks, balanced inputs and adjustable gain?

A higher input impedance, 47K ohm versus 7K ohm, and "better sound" according to Class D Audio and some of the users who have both (based on what other circuit differences I don't know).

Steve

rajacat · « **Reply #3346 on:** 16 Jun 2012, 05:53 pm »

Thanks Steve,

I guess I should plow through the entire thread. I see that there are different power supply options as well plus the various mods and how they affect sound quality. I'm mostly concerned with SQ. Power is secondary since I will have very efficient speakers that will be bi amp'd.

..Roy

Nick77 · « **Reply #3347 on:** 16 Jun 2012, 08:01 pm »

Quote from: rajacat on 16 Jun 2012, 05:53 pm

Thanks Steve,

I guess I should plow through the entire thread. I see that there are different power supply options as well plus the various mods and how they affect sound quality. I'm mostly concerned with SQ. Power is secondary since I will have very efficient speakers that will be bi amp'd.

..Roy

Roy the SDS series is well worth the extra price of entry, the sonics are a real nice improvment over the CDA. SDS series has a high end input reciever that really lowers distortion. Definitely get the larger PS, and if you like to tinker you could even buy it w/o caps and install the Panasonics which take it to another level.

redjr · « **Reply #3348 on:** 19 Jun 2012, 06:57 pm »

Hi all,

Does anyone know if the Class D model (CDA-258) amp allows for easily modding it to accommodate a gain control like the SDS-258 offers? Are there PCB holes where a 3-pin header could be soldered in - after presumably removing a fixed resistor?

Edit: A quick look thru of the manual suggests there are no obvious connections for a gain control so I may have found my answer. Without a schematic of the circuit, and all the SMDs on the underside, it sounds like it would be more than I'm willing to tackle now, but not out of the realm of possibility.

I'm thinking about this unit to purchase over the SDS model due to the price, but would like the gain control option.

bruson2 · « **Reply #3349 on:** 19 Jun 2012, 09:09 pm »

I have a SDS 258 amp.

Just soldered the speaker wires on the bottom of the board on the screw terminals solder point.

Cheap solution for cleaner, clearer sound top to bottom. Easy to hear the difference.

rajacat · « **Reply #3350 on:** 25 Jun 2012, 01:03 am »

I'm about to place an order for one of the SDS amps. I'm vacillating between the SDS-254 and the 224. They're both about the same cost and I'll be using them with very efficient speakers: biamped wave guides SEOS-18's with AE15m woofers and yet to be determined compression drivers for the waveguides. The SDS's will be used for the woofers.

Since the difference in cost is negligible, I'm leaning towards the 254's unless the 224's have better SQ or some other advantage I don't know about. Another reason is if I happen to build some other less efficient speakers in the future the 254's might be a better match.

Are there any faults in my reasoning? Would the 254' s be overkill?

...Roy

Barry_NJ · « **Reply #3351 on:** 25 Jun 2012, 02:50 am »

Roy,

Your question is likely best directed to Tom at Class-D Audio. I really doubt many, if any, here have A-B'd the 2 amp boards in question.

My honest opinion is there is no such thing as too much power, having plenty of extra head-room/power available for sudden crescendos is a good way to add life and effortlessness to a system.

Best, Barry

mboxler · « **Reply #3352 on:** 25 Jun 2012, 02:57 am »

I'd go for the 254's. $35 for another 3dB ain't bad. Also, don't forget to use ACircle as the promo code...5% off!

Mike

rajacat · « **Reply #3353 on:** 25 Jun 2012, 04:21 am »

I'm going for the 254's

The TD15m's can take a lot of power and I will be using a miniDSP to implement digital crossovers which will eat some of that power. Mike, thanks for the heads up on the promo code.

...Roy

justd · « **Reply #3354 on:** 29 Jun 2012, 05:21 pm »

I set out to make 6 channel amp for my home theatre. I have mounted the amps in the following manner. I have designed my equipment console to be kept below the screen, in which this contraption will be put and the transformers will be put just behind it inside the console.

Do you guys think i will run in to any problems with this setup. I did a trial run today and i am getting a lot of hum in my speakers. I am trying to investigate any ground loop problems. But any insight or help from you guys will be greatly appreciated.

mboxler · « **Reply #3355 on:** 29 Jun 2012, 10:03 pm »

What kind of speaker binding posts are you using? They look like RCA inputs.

Mike

Barry_NJ · « **Reply #3356 on:** 30 Jun 2012, 03:39 am »

Quote from: mboxler on 29 Jun 2012, 10:03 pm

What kind of speaker binding posts are you using? They look like RCA inputs.

Mike

+1

justd · « **Reply #3357 on:** 30 Jun 2012, 05:09 am »

yes they are RCAs. i have terminated my speaker cables with RCA plugs. The idea of designing this mount was to access the amp from above and not from behind as is the usual. May be i will post the whole assembly with the position of the processor as well.

Are RCAs a bad idea?

srb · « **Reply #3358 on:** 30 Jun 2012, 05:45 am »

I was looking at the photos and scratching my head. My first thought that the reason for the odd layout was to have the shortest possible input and output wiring, but you subsequently said it was for connection access.

I always put rubber grommets in holes in sheet metal that wiring passes through. I'm not sure exactly why you're getting hum, but I will say that I have never seen a layout where the boards are so close as to almost touch each other.

Steve

walkern · « **Reply #3359 on:** 30 Jun 2012, 01:29 pm »

Very often cable boxes or Sat / Dish receiver boxes will carry hum into your system. Try disconnecting everything from your AV receiver or pre/pro, and then fire up the AM or FM, and see if your hum is gone. If so, systematically begin connecting sources one at a time until the hum returns... and then you'll know what the culprit is.