My Cute AMPCAMP Built

[keith_correa]

I apologise for being presumptuous. Thanks for correcting me.

 

[shanindia]

I noticed the OPS regulators running hot after Om pointed it out. I will replace the resistors once I receive them; for now I have added makeshift heatsinks. i also plan to do the 2.2k mod to ACA.

As Sachin mentioned, the amp is being powered by a laptop adaptor; the r-core is just for DCB1. The internals shot is attached.



One thing I noticed that on ACA even the mp3's sound good. I was apprehensive as better the system more the faults of mp3 come out. However the ACA sounds sweeet... :licklips: The guitars, sitar, tabla, cymbals etc. sound as if playing in the room. It sounds so... organic. definitely not artificial or bland. Awesome!

 

[madhurvyas]

Hi, What would be the price of complete kit without the case heatsink, also if I want to add volume controls to it, I can make my own cabinet.

 

[shanindia]

Hi, What would be the price of complete kit without the case heatsink, also if I want to add volume controls to it, I can make my own cabinet.

Contact sachu888 for the kit. As this is only power amp, you would need a preamp which would have the volume control.

 

[shanindia]

Congratulations, nice build.

One more thing I found. When we are using only DCB1 on 10V, supplied r-core is 22-0-22, (which meant for previous B1 24V case) is overkill. If possible then replace R1, R2 (those big 1R resistances) on OPS with 500 ohm, 2W. This will reduce input voltage to regulators at 20mA current case by 10V making it run cooler. Input to regulators is 33V with 22-0-22 r-core. It could be 250ohm,2W for double DCB1 case.
Other way to use 12-0-12 r-core with stock parts.

Recalibrate output voltage after replacing transformer or resistances.

I replaced the three resistors with 500 ohm, 2w ones today. However, afterwards the output voltage reading is unusual - the voltage reading is across +15 and -15 (top and bottom pins), ground and -15 (middle and bottom pins). It should have been between +15 and ground (top and middle), and -15 and ground (bottom and middle). Any ideas what could be wrong?

 

[shanindia]

I replaced the three resistors with 500 ohm, 2w ones today. However, afterwards the output voltage reading is unusual - the voltage reading is across +15 and -15 (top and bottom pins), ground and -15 (middle and bottom pins). It should have been between +15 and ground (top and middle), and -15 and ground (bottom and middle). Any ideas what could be wrong?

I found out the issue... seems one of the solder pads got damaged while removing older resistor. Shorting the resistor leg with another terminal in the same line solved the problem. Output is fine now.

 

[sarathssca]

Could you please suggest a matching preamplifier (with volume control) for ACA amp, which can use same laptop brick (SMPS) power supply?
Looking at forums, many people are using B1 or DCB1 preamplifier.
B1 preamp requires only a single positive voltage from power supply where as DCB1 preamp requires both positive and negative voltages from the power supply.
Can we use the same laptop brick power supply which powers the ACA amp, or does these needs a separate linear power supply?

Also can we house both the pre amp and ACA amp in same cabinet?

thanks
S Sarath

 

[jls001]

Can we use the same laptop brick power supply which powers the ACA amp, or does these needs a separate linear power supply?

DCB1 needs +/- 10V supply.

 

[sarathssca]

So if we want to use the same single voltage laptop brick power supply for preamp also as used for ACA amp, then B1 preamp would be better option?
can B1 preamp work well with laptop brick smps power supply or need a linear power supply only?

 

[spirovious]

So if we want to use the same single voltage laptop brick power supply for preamp also as used for ACA amp, then B1 preamp would be better option?
can B1 preamp work well with laptop brick smps power supply or need a linear power supply only?

B1 runs on 18-21V DC.

 

[sarathssca]

B1 runs on 18-21V DC.

So would it be better to pair ACA amp with B1 preamp and use the same power supply (laptop 90w SMPS brick) for both, and put both of them in same cabinet?
How would be sound quality for B1 preamp with SMPS power supply?

 

[omishra]

Re: My Cute AMPCAMP Build started

Though Pass B1 designed to be used with wall adapter, people reported more clarity with good regulated linear PS. Sound with SMPS and B1 was found be edgy or sharp. At least both sound different.

 

[deba]

Great Cabinet.......post some pics after the final built..........

 

[madhurvyas]

My ACA has been running for few days now, I can say its opposite of this thread title "My ugly lil ACA", but its completely made out of scrap, except the connectors and ACA kit.
I upgraded few resistors and cap, which were in direct sound path. I also did 2k2 mod to get extra power and better overall results, my heatsink is fan cooled so it takes all the extra heat, though i can feel the warmth. I solderd resistors on the under side so they are not visible.

WP_20150115_15_17_20_Pro by madhurvyas1, on Flickr


Thought of adding Simple active amp inside the ACA, then decided to keep it separate.
WP_20150115_15_22_50_Pro by madhurvyas1, on Flickr

 

[madhurvyas]

Why my mobile phone's touch acts weird when its connected to the amp/preamp, is there some ground issue, or something else, my all rca inputs are on acrylic sheet, not touching any metal part of amp.

 

[kaushik]

cell cam pics dust and make nice looking amps look dusty .. thats a very good build ... images needed to be taken with lesser lit area them the small dust wont appear

My ACA has been running for few days now, I can say its opposite of this thread title "My ugly lil ACA", but its completely made out of scrap, except the connectors and ACA kit.
I upgraded few resistors and cap, which were in direct sound path. I also did 2k2 mod to get extra power and better overall results, my heatsink is fan cooled so it takes all the extra heat, though i can feel the warmth. I solderd resistors on the under side so they are not visible.

WP_20150115_15_17_20_Pro by madhurvyas1, on Flickr


Thought of adding Simple active amp inside the ACA, then decided to keep it separate.
WP_20150115_15_22_50_Pro by madhurvyas1, on Flickr

 

[madhurvyas]

Thanks kaushik,
These are indeed cellcam pics, but from nokia 1020, and i cannot live without dust, as im in middle of desert , still I'm in process of completing the amp, so havent given it a wipe.

 

[kaushik]

inprogress pics we love with dust paint spills ....
fully wiped at the end for sure

nice green pcbs you have , I have UV resin for the mask ..get too lazy to do it


I hope it will be an excellent upgrade

 

[madhurvyas]

PCB and components are from Sachin.
Once done I will surely give it a nice wipe and improve the finishing.

 

[sarathssca]

I am going to build a ACA amp, received the kit..
Could you please suggest whether to go for the normal build for 5w+5w or the resistor modded one which is of 6w+6w?
what are the pros and cons of the mod?