Hi guys im after a nice simple design for a preamp to got with the apox volume control setup.
Any ideas ?
just needs to be clean - no balance or tone controls.
Also if possible a pcb be avaliable
I'm open to more complex ideas - but would prefer simple. ie not discrete ( woud be nice but pcb design etc is not my forte )
Any ideas ?
just needs to be clean - no balance or tone controls.
Also if possible a pcb be avaliable
I'm open to more complex ideas - but would prefer simple. ie not discrete ( woud be nice but pcb design etc is not my forte )
The High Quality Preamp from Elliott Sound Products seems to fit your criteria, and you can buy the PCB.
An externally hosted image should be here but it was not working when we last tested it.
I looked at that one - but wasn't sure how to bypass the balance .
Buying from these guys would be great cause they are just up the road from my place 🙂
Buying from these guys would be great cause they are just up the road from my place 🙂
Omit VR2. No balance control.
But note well Rod's comment about the effect of the pot on sound quality.
But note well Rod's comment about the effect of the pot on sound quality.
Nice!
Which microcontroller will you be using for the pot? Or can you connect a rotary encoder directly to that potentiometer chip?
I'm trying to get started with programming og PIC's, but it's certainly not easy, when my only programming experience is with PHP... 🙁
But I'm wondering - what would it require to do a balanced version of your pot-circuit? I'd need two pots, but how would I connect them to the PIC/rotary encoder?
Which microcontroller will you be using for the pot? Or can you connect a rotary encoder directly to that potentiometer chip?
I'm trying to get started with programming og PIC's, but it's certainly not easy, when my only programming experience is with PHP... 🙁
But I'm wondering - what would it require to do a balanced version of your pot-circuit? I'd need two pots, but how would I connect them to the PIC/rotary encoder?
Hi , actually i have a circuit diagram for the balanced too....
I will use ATmega8515 or ATmega16/32. depends on my memory needs. And they are programmed in "C"
More to come...
I will use ATmega8515 or ATmega16/32. depends on my memory needs. And they are programmed in "C"
More to come...
The Balanced version is here : mirandp2-1.pdf
As you can see the two XWM8816 is connected in parralel on the SPI bus (MUTE,CS1,SDI,SCLK) if you want to control them individual you need to seperate CS1. You still use the same SPI interface. Only chip select is separated.
As you can see the two XWM8816 is connected in parralel on the SPI bus (MUTE,CS1,SDI,SCLK) if you want to control them individual you need to seperate CS1. You still use the same SPI interface. Only chip select is separated.
Great. I'll dig into this whenever I get around to making a PIC burner.
Have you thought about biasing the opamps into class A? With AD8620/AD8610 the improvement is minimal if existing at all, but with OPA627 there should be a noticable improvement.
Btw - how many microcontrollers do you end up using for the whole preamp?
Have you thought about biasing the opamps into class A? With AD8620/AD8610 the improvement is minimal if existing at all, but with OPA627 there should be a noticable improvement.
Btw - how many microcontrollers do you end up using for the whole preamp?
Actually i have had a conversation with Werner Ogier. About different circuit types.
So after some thoughts, i will be making a motherboard with the main powersupply ( without transformer), input connectors, output connectors and relays for input switching.
There will be a frontpanel, with the micro, IR receiver, keys, option for rotary encoder, and LCD. there will be a connector to the mainboard through a 20 - 40pol flatcabel.
Then attenuator, inputbuffer and outputbuffer will be on a daughterboard. Then i will make cheap version, singleended. No need to mount XLR connectors.
Then there will be some more sophisticated daughterboard versions in singleended and balanced version. When you go for balanced you mount the last relays and XLR connector.
I hope i can keep the cheap version at around 2000DKR.
It makes it possible to upgrade your preamp later, without the need to buy a complete solution at once!
Then it also will be possible to make a new attenuator section with another attenuator.
..... ahhhhhhh .... 🙂
So after some thoughts, i will be making a motherboard with the main powersupply ( without transformer), input connectors, output connectors and relays for input switching.
There will be a frontpanel, with the micro, IR receiver, keys, option for rotary encoder, and LCD. there will be a connector to the mainboard through a 20 - 40pol flatcabel.
Then attenuator, inputbuffer and outputbuffer will be on a daughterboard. Then i will make cheap version, singleended. No need to mount XLR connectors.
Then there will be some more sophisticated daughterboard versions in singleended and balanced version. When you go for balanced you mount the last relays and XLR connector.
I hope i can keep the cheap version at around 2000DKR.
It makes it possible to upgrade your preamp later, without the need to buy a complete solution at once!
Then it also will be possible to make a new attenuator section with another attenuator.
..... ahhhhhhh .... 🙂
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