no posted builds yet?? where did all those pcbs go? not very gratifying for the pcb designer 
.
and I thought my build would be the last, hmmmm. Anyways, I am finishing my two Aleph Ps. they are identical. one will drive the top and the other one the bottom of a biamped system. they have each a 1kOhm Dantimax relay volume attenuator. the idea is to set each independently with a button and then move them both up/down with the same remote.
I added also the relay capability to have them turned on by the Xover which is upstream, and also for AlephPs to turn on the amps downstream (so i do not need to run around the room turning a zillion buttons on/off.
here are the pics of the first one. the box is still open since I need to order the fuses in another size (last minute change).
.and I thought my build would be the last, hmmmm. Anyways, I am finishing my two Aleph Ps. they are identical. one will drive the top and the other one the bottom of a biamped system. they have each a 1kOhm Dantimax relay volume attenuator. the idea is to set each independently with a button and then move them both up/down with the same remote.
I added also the relay capability to have them turned on by the Xover which is upstream, and also for AlephPs to turn on the amps downstream (so i do not need to run around the room turning a zillion buttons on/off.
here are the pics of the first one. the box is still open since I need to order the fuses in another size (last minute change).
Attachments
for yoke:
relays 1&2 (Hamlins) are the same as on Papa's schematic. this preamp benefits from having an input attenuator for hot sources. these turn the input resistors on/off for a few discrete gain steps. check the service manual.
the other two relays (Spartans or equivalent), can be used instead of a jumper to short the input or output to ground if the preamp is to run SE and not balanced.
all relays take a 5V from an external PS and are controlled by the 4pole DIP switch.
good luck.
relays 1&2 (Hamlins) are the same as on Papa's schematic. this preamp benefits from having an input attenuator for hot sources. these turn the input resistors on/off for a few discrete gain steps. check the service manual.
the other two relays (Spartans or equivalent), can be used instead of a jumper to short the input or output to ground if the preamp is to run SE and not balanced.
all relays take a 5V from an external PS and are controlled by the 4pole DIP switch.
good luck.
Well, it isn't based on the TS circuit boards, but older ones.
Here a little update from my 1.7 project.
I'm still strugling with mounting the rotary encoder. Alignment is a bit of a problem.
I'm using :
- Arduino for controls
- Twisted Pear attenuator
- AMB based source selection / att relais control
- LCD or VFD display
All is controlled via I2C.
Regards,
Nick
Here a little update from my 1.7 project.
I'm still strugling with mounting the rotary encoder. Alignment is a bit of a problem.
I'm using :
- Arduino for controls
- Twisted Pear attenuator
- AMB based source selection / att relais control
- LCD or VFD display
All is controlled via I2C.
Regards,
Nick
Attachments
First chanel up
First chanel is up and running.
After some problems with my scope (signal generator was not working) I finally could see some progress.
For single end operation I know that the input (-)signal most be shorted to ground my question is do I ground the output too ?
I read the manual and it only mentions the short on the input.
Ric
First chanel is up and running.
After some problems with my scope (signal generator was not working) I finally could see some progress.
For single end operation I know that the input (-)signal most be shorted to ground my question is do I ground the output too ?
I read the manual and it only mentions the short on the input.
Ric
I am running mine balanced but AlephP should be able of running any combination of input and output, i.e. it can also run as a converter from XLR to RCA or vice versa. hence on the board (if you are using mine) there is a separate relay to short output minus to gnd if you want the output to run single ended too.
So does it mean that the input and output most be grounded for single end operation (single in/single out) ?
I can see on the scope the gain changing when I change the dip switches without grounding the (-) on the output
I made my on boards (from Acaudio.de)
Ric
I can see on the scope the gain changing when I change the dip switches without grounding the (-) on the output
I made my on boards (from Acaudio.de)
Ric
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yes, shorting minus (-) signal to gnd on the input and the output will make each run as single ended.
p.s. not sure of your dip switch configuration since you are using another board. on mine the first two switches control the input attenuator settings since some attenuation may be required for hot sources.
p.s. not sure of your dip switch configuration since you are using another board. on mine the first two switches control the input attenuator settings since some attenuation may be required for hot sources.
Thanks
Got second chanel running
Now going for the dificult part... volume controller for the preamp, encoders, lcd, relays.
Will post picture soon.
Ric
Got second chanel running
Now going for the dificult part... volume controller for the preamp, encoders, lcd, relays.
Will post picture soon.
Ric
Wish these boards were available when i made mine
I wish these boards were available when i built mine. I had to mount the big WIMAs off board and it took up a lot of space and isnt as tidy as id like.
With the Twisted pair attenuators, has anyone had any incosistencies in volume? I have a strange jump then drop every several volume clicks. I suspect i recieved some mis labled resisitors or mis installed them.
Andrew
I wish these boards were available when i built mine. I had to mount the big WIMAs off board and it took up a lot of space and isnt as tidy as id like.
With the Twisted pair attenuators, has anyone had any incosistencies in volume? I have a strange jump then drop every several volume clicks. I suspect i recieved some mis labled resisitors or mis installed them.
Andrew
Andrew,
I have the TP Joshua Tree in my Aleph P1.7 clone and it works well. Then I built a Pumpkin and put a Joshua Tree in that and I'm having all sorts of issues like you describe. Pops and clicks and dips in volume. I swapped the two Joshua Trees around and got the same results. It seems it may be tricky to get the JT to match well with amps. I gave up on the Pumpkin because of these problems.
I have the TP Joshua Tree in my Aleph P1.7 clone and it works well. Then I built a Pumpkin and put a Joshua Tree in that and I'm having all sorts of issues like you describe. Pops and clicks and dips in volume. I swapped the two Joshua Trees around and got the same results. It seems it may be tricky to get the JT to match well with amps. I gave up on the Pumpkin because of these problems.
Aleph1.7
I made my own boards from a site that doesn't exist any more.
They are well design and do allow for wima caps (board size is 100x160mm) and are single sided
I made my own boards from a site that doesn't exist any more.
They are well design and do allow for wima caps (board size is 100x160mm) and are single sided
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I'm just going to have a go at building the P1.7 with boards from KK-PCB.
Has anyone got any experience with these ?
Has anyone got any experience with these ?
I'm just embarking on a P1.7 build out of plain curiosity.
I notice on early posts that some guys have used 2 x PSU boards.
I am using the KK-PCB boards but only have the one PSU, will this be sufficient ?
I notice on early posts that some guys have used 2 x PSU boards.
I am using the KK-PCB boards but only have the one PSU, will this be sufficient ?
Sheesh! That's a huge power transformer. The the original Aleph P transformer is what I used and its small enough to fit on the side of the chassis. It IS best to have independent regulators for each channel but where you going too put it with that transformer. I used a common n rectifier pub feeding the on board regulators that are the n each of my PCB's. I suppose your transformer could be external in another small box.
BTW: My Aleph P has been running continuously for almost one year now.... I never shut it off.
Mark
BTW: My Aleph P has been running continuously for almost one year now.... I never shut it off.
Mark
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there is room for another PSU board. move the transformer a little closer to the back and there will be room for 2 PSU boards side by side in front of the transformer.