The main board set is 100x202mm, the main board is c. 100x170mm.
Sorry it took so long to respond- ice storms resulted in no internet for 2 days.
Sorry Wyn, didn't see the reply until now!
Only hiccup I had was self inflicted, I put the SE/BAL jumpers in wrong, and had a really badly distorted/low output initially. Once I fixed those, I was in business.
I subbed the OPA1642s for the OPA1656s in the warp filter because of the latter's unavailability. To my untrained ear, they seem to be working well in the role. I still have the 1656s on order (Mouser is still saying mid April) to install when they show up.
I'll go take some pictures in the next day or three.
Hi Alain,
not a problem. There are several available. The price is $25 US per board plus $16 shipping to Belgium.
So, a single board is $41 total, two are $66 sent via Paypal, friends and family,
to wynpalmer4@gmail.com.
If you do not use Friends and Family please add an extra $2 to each quantity.
Regards,
Wyn Palmer
not a problem. There are several available. The price is $25 US per board plus $16 shipping to Belgium.
So, a single board is $41 total, two are $66 sent via Paypal, friends and family,
to wynpalmer4@gmail.com.
If you do not use Friends and Family please add an extra $2 to each quantity.
Regards,
Wyn Palmer
Hello Wyn,
Thanks for the answer,
I have a question, to have a MM and MC I need to populate 2 boards (one for MM only and the other for MC only), and swap the power supply and Outputs ?
So 2 boards:
2*(25+2$) + 16$ Shipping = 70$
I already have the enclosure, I wanted to build a Phono Pre a long time ago...
And it did take all yesterday afternoon to read all the thread, great job!
PS: I don't remember how to add pictures with the new version
Regards,
Alain.
Thanks for the answer,
I have a question, to have a MM and MC I need to populate 2 boards (one for MM only and the other for MC only), and swap the power supply and Outputs ?
So 2 boards:
2*(25+2$) + 16$ Shipping = 70$
I already have the enclosure, I wanted to build a Phono Pre a long time ago...
And it did take all yesterday afternoon to read all the thread, great job!
PS: I don't remember how to add pictures with the new version
Regards,
Alain.
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The power supplies don't need to be swapped. The current consumption is quite low.
You can populate the phono section of a board, but not the rest, and route that to the populated part of a second board- including the warp filter and the line/preamp stage, if you wish. Or, you can just operate a MM and MC stage in two boards and route them through the line buffer to the output using a switch.
It's a very flexible configuration.
Yes. that is the price. I've sent boards to dozens of countries- including Belgium.
You can populate the phono section of a board, but not the rest, and route that to the populated part of a second board- including the warp filter and the line/preamp stage, if you wish. Or, you can just operate a MM and MC stage in two boards and route them through the line buffer to the output using a switch.
It's a very flexible configuration.
Yes. that is the price. I've sent boards to dozens of countries- including Belgium.
I have no idea what you are saying. The MM using the OPA1641 and the MC using the LT1115 (orAD797) are completely different circuits and have a second stage that precedes the input (MC or MM ) selector switch.
Besides, the phono stage can have two input opamps in parallel, and it is quite OK to connect them as such despite no devices having identical GBWPs.
The circuits are combined at the output of each opamp with a coupling resistor , effectively driving a two input, one output, low pass function which "averages" the inputs.
Besides, the phono stage can have two input opamps in parallel, and it is quite OK to connect them as such despite no devices having identical GBWPs.
The circuits are combined at the output of each opamp with a coupling resistor , effectively driving a two input, one output, low pass function which "averages" the inputs.
Two new mini add on boards have been constructed to provide more functionality- a mono/balance board where the functions operate concurrently with the same range/law as before, and an output relay board that delays the output turn on by c. 2s after power up, only allows output signals when the supply voltage exceeds +/-12v, will automatically mute/unmute when a headphone is inserted/removed from the headphone socket, and will allow for switched mute/unmute.
A v3.0 board with these functions built in is under consideration.
Any interest?
A v3.0 board with these functions built in is under consideration.
Any interest?
In a v3 board, no. I'm only just getting together a mouser order for the V2 (using the Mouser carts listed in #48) I purchased last year (don't ask). But mini boards? Yes, I'd take a set to add to my V2.
Which board or boards?
All the boards are optimized for +/-15v, but will operate at 10-12V with some loss of overload margin.
The switch/protect board would have to have lower voltage zeners for operation.
The v2.0 phono/line amp is c. 100mm by 210mm.
The relay board can have one or two "stereo" relays. If only one is chosen a 270 ohm R should be removed from each leg.
For 10v minimum operation the zeners should be dropped from 10v to 5v or so, and the relays will have to be a lower voltage- 12v rather than 24v.
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Don't ask? Does this mean that you've not made progress.
There's an Audio Karma user in Silchester that has recently completed a couple of builds.
He was the one that requested the modified mono/balance and output muting relay functions.
Perhaps the two of you should get in touch (@CV1040 is his moniker) to arrange to get some of the add on boards made as at this time there is insufficient demand for me to have a set fabricated, although there will be Gerbers available.
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Zero, zilch, nada. In part because there were other things I needed to do but didn't want to, so decided to deny myself the build of your amp until I'd got the unappetising stuff out of the way.
Also I got stuck in Spain as several flights to UK were cancelled delaying things even further, but that really doesn't count as hardship
@wynpalmer2 - yes, one board as for phonostage only, not the headphone amp etc.
I have been (very happily) using one of hypnotoads AD797 boards, but yours looks so interesting that my interest is piqued. The question on the sizes was just to see if it would fit in an existing chassis. I have a very high quality +/- 11V supply I would like to use if possible. I'll l go read the thread on AK and come back to you for a couple of boards.
Fran
I have been (very happily) using one of hypnotoads AD797 boards, but yours looks so interesting that my interest is piqued. The question on the sizes was just to see if it would fit in an existing chassis. I have a very high quality +/- 11V supply I would like to use if possible. I'll l go read the thread on AK and come back to you for a couple of boards.
Fran
Zero, zilch, nada. In part because there were other things I needed to do but didn't want to, so decided to deny myself the build of your amp until I'd got the unappetising stuff out of the way.
Also I got stuck in Spain as several flights to UK were cancelled delaying things even further, but that really doesn't count as hardship
Steven, any help I can provide let me know? I'll be an early adopter of the add on boards too – as soon as Wyn and Sean (PCB guy) have them available.
Inspirational V2 MC c/w HP amp build picture attached.
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I've ordered the parts for the relay board, and Sean will provide me with the layout info. so that I can buy the minimum three prototype boards. I'll build one, and if all is OK I can ship the remaining two to the UK. Let me know if you're interested.
I expect that it will be approaching the end of April before the prototype is built and verified.
I expect that it will be approaching the end of April before the prototype is built and verified.