Amp Camp Amp - ACA

very nice indeed! designwise its nice not to have the PSU in case (or at least could be).

you say you have B1 buffer integrated, is it sufficient with that 1V Ipod swing? I will just use it in my studio and it won´t see any other device (poor amp like a indoor cat:D )

Buffer is buffer, it doesn´t have any gain or it has gain = 0.9. ACA has gain about 5 (14dB). If it is enough depends on your speakers. If you need more gain, you don´t need buffer, but preamp.
 
yes, i´m aware of that, but i dont know how much swing ACA needs for full output.
It might be enough anyway but just to know before putting things together would be cool.

Sorry if my questions are too noobish, but why are one uses B1 in same case? Isnt frontend of ACA a Buffer on it´s own? Or has the Volume pot to be buffered?
 
yes, i´m aware of that, but i dont know how much swing ACA needs for full output.
It might be enough anyway but just to know before putting things together would be cool.

Sorry if my questions are too noobish, but why are one uses B1 in same case? Isnt frontend of ACA a Buffer on it´s own? Or has the Volume pot to be buffered?

ACA can swing half of the power supply voltage. To maximize swing voltage in both directions, you must adjust output to half PSU voltage - that is the pot for.

If you put volume pot just before ACA, the pot messes with feedback network, so you need to buffer it. If your source has volume control and low enough output impedance (preferably lower than 1k), you don´t need any additional buffer before ACA.
 
thanks for your time and good explanation. Ipods have outputimpedance of about 5-8 Ohms so that seems to be ok.
Nevertheless i want to have a Volume control on the amp, it´s just better to handle and digital **** is happy to go full power into input and than scaled down, has simply more steps than in opposite to analog source (at least as far as i know, and sounds plausible to me).

thanks again and i´m sure i´ll come back with some basic stuff to ask for :)

stefan
 
Hi guys just of my diy ACA enclosure I fitted a passive stepped attenuator and a 4 pin xlr out on the front for my HE-6 headphones works a treat. I found some used heat sinks on ebay and used bamboo chopping board for the wooden bits.

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Hello everyone!

It's my first post on DIY Audio and I am excited for it to be about my amp camp amp! I already have the boards soldered and am itching to get this little jewel "burning."

My problem is with the power supplies I purchased. Since DIY Audio did not have the full kit in stock (at least when I got started) I sourced all the parts one by one. Which landed me with a power supply from Marlin P Jones. It is 19 VDC, 2.6 A (MODEL EM10602D).

19 Volt Adapter Power Supply, 2.6A, Bi-Pin | MPJA.COM

The little devil comes with a Hirose RP34L-5PA-2 series Bi-Pin connector as an output. The receptacle for this pin is tiny and laughably impossible for me to mount in a wooden amplifier case. I want to cut it off and replace with a different type of pin connector- preferably a large barrel connector. There are a lovely one thousand and twenty six options on digi-key.

Now, I'm not asking anyone to do my homework for me, but I am sure someone out there has already encountered this on the amp camp amp! And if not, there are sure to in the future...and now there will be a nice thread with (hopefully, in a few days) a solution for the whole world.

Will keep everyone updated. Please let me know if you have a suggestion for a new type of pin/plug (preferably barrel)! I really want this to have a nice, pretty, finished look. No redneck amp camp amp cases!!! Based on the length of the power supply cable, I should have about 50 tries to get this right before I run out of cable. ;)
 
My problem is with the power supplies I purchased. Since DIY Audio did not have the full kit in stock (at least when I got started) I sourced all the parts one by one. Which landed me with a power supply from Marlin P Jones. It is 19 VDC, 2.6 A (MODEL EM10602D)....The little devil comes with a Hirose RP34L-5PA-2 series Bi-Pin connector as an output....I want to cut it off and replace with a different type of pin connector- preferably a large barrel connector
You can go back to Marlin P. Jones: DC Power Connectors | MPJA.COM e.g.: Part #32104 PL (chassis power connector), Part #19084 PL (power plug barrel end)
 
Here is how the speak on look's
 

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Gentlemen, I need your advice, please.

I am currently busy building an "active-speaker-concept", which will use 2 stereo-ACAs to drive the tweeters and the middle tones.
I have built a prototype on an intermediate heatsink, since I do not yet know, which dimensions the final case will have.

I decided to use an original DELL laptop PSU (rated at: 19.5VDC / 4.62A) to drive an ACA-pair.
The output of the DELL-Laptop PSU shall be connected to a NEUTRIK Power connector.

After I have cut off the original connector, I found this (image 2): three very tiny wires coloured white, black and blue.

Will these wires be strong enough to power the ACA-pair?
Which are the function of these 3 wires?
The black wire is supposed to be GND. What about the blue and the white colour - wires?

Can you please help me?

Best regards - Rudi_Ratlos
 

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Drbf1
It just a simple box made from 2 15*15cm sinks, 3 pcs of metal plate ( cut from a plate ) and a Ikea handle.

Rudi
I use 2 * dell bricks. I added an xtra 10000uf, but they could not handle it. Then i attached a resistor and a diode in ( see Mr. Pass recomendation in the begining of the thread ) and it worked super.
the 2 bricks get warm, ( 35 C i guess ).

As fair as I remember the blue/black is the power, and the white is Dell stuff ( just cut it )

IF you have made the resistor hack on the ACA im quite sure you need 1 brick for one ACA
 
reenberg, you are wrong.

I inserted a 33 Ohm resistor between the clips of my DMM (expecting a current of about 600mA) and measured:
between Black and Blue: 0V
between Black and White: 18.8VDC
between Blue and White: 15 VDC

I did not yet find Mr. Pass' trick with the diode and resistor.
Can you please point me to his post?

Best regards - Rudi_Ratlos
 
Has anybody taken measurements to which shows the reduction in distortion with the addition of the R15(2.2k) resistor? Original distortion graph is below. Does anybody have the graph with the added resistor?

Do we need to bias the amp again after a few dozen hours or will the voltage stay stable?.

xampcampdamp.png