There is not yet a definitive pin designation.
I figure that the dual inline connector will use two adjacent pins for
each connection by way of redundancy, so 20 pins = 10 connections,
26 pins = 13 connections.
26 pins is the other common value, especially since it is popular with
current computer parallel cables.
Let's assume the amp uses an output follower stage and further
assume that the bias circuit is on the output stage board:
At a minimum the interface needs to address V+, V-, Gnd, +Input and
+Drive. That's five.
Also, how about -Input, -Drive, +Speaker, -Speaker.
That makes nine.
Other possibilities are Aux Gnd, Output current Sense,
Aux V+, Aux V-.
That makes 13.
What alternative or additional connections do you think you might want?
I figure that the dual inline connector will use two adjacent pins for
each connection by way of redundancy, so 20 pins = 10 connections,
26 pins = 13 connections.
26 pins is the other common value, especially since it is popular with
current computer parallel cables.
Let's assume the amp uses an output follower stage and further
assume that the bias circuit is on the output stage board:
At a minimum the interface needs to address V+, V-, Gnd, +Input and
+Drive. That's five.
Also, how about -Input, -Drive, +Speaker, -Speaker.
That makes nine.
Other possibilities are Aux Gnd, Output current Sense,
Aux V+, Aux V-.
That makes 13.
What alternative or additional connections do you think you might want?
Can you use one of these? Mouser 517-4832-6004-CP or 517-4828-3004-CP . 32 or 28 pins. 26 pin gives 1 option at Mouser, 28 pins gives 92 options and 32 pins gives 42..
June M2x orders were shipped today
Today I shipped all M2x boardsets that were
ordered in June; buyers please check your
Private Messages to find the Customs Number
or the domestic Tracking Number.
Thanks to everyone!
Mark Johnson
Today I shipped all M2x boardsets that were
ordered in June; buyers please check your
Private Messages to find the Customs Number
or the domestic Tracking Number.
Thanks to everyone!
Mark Johnson
I've been following this thread with great interest and (as soon as the boards are available) I think this might well be the next project for me.
I do have a few questions: This would be my first Pass Amp. Would the M2 be a good place to start this journey? Better than an F6 or F5 maybe?
I'm looking for a design that is rather beginner friendly and doesn't take a lot of tweaking or tuning to get it right.
This might seem odd, but it's important for me: is it quiet? Is there any noise floor to be expected or any hum / buzz issues? I know it's a bit odd but it drives me crazy if there's noise from the speakers when the music is off. 😀
Thanks!
Michi
I do have a few questions: This would be my first Pass Amp. Would the M2 be a good place to start this journey? Better than an F6 or F5 maybe?
I'm looking for a design that is rather beginner friendly and doesn't take a lot of tweaking or tuning to get it right.
This might seem odd, but it's important for me: is it quiet? Is there any noise floor to be expected or any hum / buzz issues? I know it's a bit odd but it drives me crazy if there's noise from the speakers when the music is off. 😀
Thanks!
Michi
My experience with amplifiers is that it is up to the "builder" to get the amp quiet. If you take care of PSU, wiring etc. you can get all amps "dead quiet". I just built the ACA and it is "dead quiet". Before that I had a project with making a tube amp silent. I used some of the same philosophy when building the ACA and it worked. You need to make a plan for how you place components, short wiring for input, signal ground, PSU ground, low ripple, magnetic stray fields etc. etc...….
ACA is probably the best "beginner amp".....it was made for that purpose as I understand it......and it sounds good! …..there is also a PSU for it if you don't want to built one yourself.
ACA is probably the best "beginner amp".....it was made for that purpose as I understand it......and it sounds good! …..there is also a PSU for it if you don't want to built one yourself.
I'm interested how sensitive speakers you have? I have build some amps as well, they have been dead quiet also..usually after some troubleshooting 😀. But when you connect them to 106db sensitive horns, things might turn out different 🙂
I understood the M2 was particularly quiet ,mainly due to the voltage gain of the autoformer instead of VAS. Might have neen here orvthe other thread. ZM said so iirc
I use open baffle speakers that has a sensitivity of approx. 94 dB. When I listen for noise / hum I have my ear as close to the speaker units as possible and I want to hear "nothing". If I concentrate on listening having my ear as close to the tweeter as possible I can hear a very weak "sshhyyy" but no "buzz" sound. I know from my tube project that 3 mV of hum is very audible from my listening position and that 0.8 mV of hum is audible if I put my ear close to the woofer. So I require less than 0.5 mV of hum from the output of the amp. I managed to get down to about 0.1 mV noise on the outputs of my 300b tube amp. That is "dead silent" in my case with my speakers. Think it is difficult to get lower than 100uV of noise of output of any amp. It is also difficult to measure signals at that level. At least with the equipment I have. So I can't guarantee that the values I have measured are 100% correct.
@Mixi
this amp is , per se , damn quiet
will you succeed in potential quietness , with your build ........ is thing still to be decided
this amp is , per se , damn quiet
will you succeed in potential quietness , with your build ........ is thing still to be decided
right. i take it that the design should be very quiet and - if not - it's due to my own inability to put it together correctly. i guess i'll take the challenge 🙂.
sounds like those edcor transformers are a bit hard to get. can they be sourced in europe or only straight from the US?
sounds like those edcor transformers are a bit hard to get. can they be sourced in europe or only straight from the US?
I ordered the Edcor transformers two days ago expecting to wait weeks for them, hoping that in the meantime the M2x boards would become available. Couldn't believe it when I checked my email today and found out that they've shipped already!
Just an update:
Ordered the Edcor transformers on 5/24/18 and ship date was on 6/12/18. They arrived today, 6/15/18.
On another note, I am pleasantly surprised by how small and cute they are,using super fine copper magnet wire.
Overall, very nice for the price!
Best,
Anand.
Ordered the Edcor transformers on 5/24/18 and ship date was on 6/12/18. They arrived today, 6/15/18.
On another note, I am pleasantly surprised by how small and cute they are,using super fine copper magnet wire.
Overall, very nice for the price!
Best,
Anand.
Why not investigate an "Eastern Hemisphere Group Buy" for the Edcor transformers?
Find a volunteer with lots of spare time, who lives in the Eastern Hemisphere. Convince her/him to run a diyAudio group buy of Edcor transformers, only for diyAudio members who also live in the Eastern Hemisphere.
When a large number of people have committed to buy Edcor transformers from the Group Buy, the volunteer places one order for (let's just say) 90 transformers, and pays the very high FedEx shipping fee from Edcor/USA to Eastern Hemisphere. Then the volunteer opens the big shipping box, and repackages the transformers into individual shipping cartons. These are shipped to all of the Group Buy participants, hopefully at a low shipping cost. Perhaps this procedure results in a lower total price {and a longer wait time!} for everybody.
Of course, many people may decide that it is SO much more convenient if somebody else (not themselves) becomes the volunteer Group Buy organizer. Thus it might not be easy to find a volunteer organizer. But why not do a preliminary investigation anyway?
Find a volunteer with lots of spare time, who lives in the Eastern Hemisphere. Convince her/him to run a diyAudio group buy of Edcor transformers, only for diyAudio members who also live in the Eastern Hemisphere.
When a large number of people have committed to buy Edcor transformers from the Group Buy, the volunteer places one order for (let's just say) 90 transformers, and pays the very high FedEx shipping fee from Edcor/USA to Eastern Hemisphere. Then the volunteer opens the big shipping box, and repackages the transformers into individual shipping cartons. These are shipped to all of the Group Buy participants, hopefully at a low shipping cost. Perhaps this procedure results in a lower total price {and a longer wait time!} for everybody.
Of course, many people may decide that it is SO much more convenient if somebody else (not themselves) becomes the volunteer Group Buy organizer. Thus it might not be easy to find a volunteer organizer. But why not do a preliminary investigation anyway?
ok, so my current speakers are rated at 85db. i guess that would make it easy to make the amp seem quiet. but also the m2 might not have enough juice, will it?
on the other hand, i currently use an amp with roughly twice the output power and a gain of 26 and rarely turn the volume beyond 12 o'clock.
on the other hand, i currently use an amp with roughly twice the output power and a gain of 26 and rarely turn the volume beyond 12 o'clock.