As already mentioned earlier in the F5Pi thread, we have all the ingredients that will also make a nice Preamp.
It has taken much longer than we wanted, but it is finally playing music since yesterday.
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7524606
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7538379
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7741027
As always, I don't comment on subjective sonic impressions.
I'll leave it to Fran to tell you what he thinks, when he has enough hours on it.
Happy reading,
Patrick
.
It has taken much longer than we wanted, but it is finally playing music since yesterday.
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7524606
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7538379
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7741027
As always, I don't comment on subjective sonic impressions.
I'll leave it to Fran to tell you what he thinks, when he has enough hours on it.
Happy reading,
Patrick
.
Attachments
There are cook books which detail all the recipes to the last 0.5g.
There are (more advanced) cook books which only tell you what ingredients to use and how to put them together.
The experienced readers for the latter can adjust the amount to their local ingredients, and individual tastes.
And this is actually built, and measured, and playing.
😊
Cheers,
Patrick
There are (more advanced) cook books which only tell you what ingredients to use and how to put them together.
The experienced readers for the latter can adjust the amount to their local ingredients, and individual tastes.
And this is actually built, and measured, and playing.
😊
Cheers,
Patrick
Given a modest understanding of the F5 (and/or F5m) it is reasonably straightforward to reverse engineer the circuit of the F5 preamp from the picture of the complete circuit board.
The remaining tweaks would be a matter of preference.
The remaining tweaks would be a matter of preference.
I am the fortunate one to be able to listen to this preamp and that is my messy bench in the video below!
Early indications are that the sound quality is very good indeed, but I need some time to listen with a few different amps and a few different sets of speakers, and likely a few friends as well. Lots of detail, great soundstage, tight firm bass, no harshness..... need I say more. It takes time though to listen really critically for a while, so bear with me while I do that.
The build is very neat indeed, as you would expect from a master, and functionally covers all the bases. Personally, I like to have 6 inputs as I run a number of different sources in rotation, 6 inputs covers all my needs. The left hand knob switches source and the right hand knob has the rotary encoder for the attenuator as outlined in the PDF in the first post. There is no turn on or turn off thump to speak of with my setup and nothing gets much above room temperature. The other thing is the silence - I was listening this evening to some tracks and at the end of the song there was some tape hiss - then the track actually ended and the silence was just that. I think that is one of the things that gives such great detail.
Early indications are that the sound quality is very good indeed, but I need some time to listen with a few different amps and a few different sets of speakers, and likely a few friends as well. Lots of detail, great soundstage, tight firm bass, no harshness..... need I say more. It takes time though to listen really critically for a while, so bear with me while I do that.
The build is very neat indeed, as you would expect from a master, and functionally covers all the bases. Personally, I like to have 6 inputs as I run a number of different sources in rotation, 6 inputs covers all my needs. The left hand knob switches source and the right hand knob has the rotary encoder for the attenuator as outlined in the PDF in the first post. There is no turn on or turn off thump to speak of with my setup and nothing gets much above room temperature. The other thing is the silence - I was listening this evening to some tracks and at the end of the song there was some tape hiss - then the track actually ended and the silence was just that. I think that is one of the things that gives such great detail.
The interesting thing in that video is the Ring LED on the right hand side.
We are using the W-ONE relay ladder attenuator with 128 steps and 3-digit 7-segment display.
The latter is based on the MAX7219 LED driver.
With only 32 LEDs around the ring, each LED has to be assigned to 4 steps.
To partially get round that, we implemented an intermediate state where 2 neighbouring LEDs are on with half the intensity.
That means now we can now have 63 states in total with 32 LEDs.
Fran called it "Chasing LED".
I think it is a nice name.
😊
Patrick
We are using the W-ONE relay ladder attenuator with 128 steps and 3-digit 7-segment display.
The latter is based on the MAX7219 LED driver.
With only 32 LEDs around the ring, each LED has to be assigned to 4 steps.
To partially get round that, we implemented an intermediate state where 2 neighbouring LEDs are on with half the intensity.
That means now we can now have 63 states in total with 32 LEDs.
Fran called it "Chasing LED".
I think it is a nice name.
😊
Patrick
There are details you don't see.
Like the mains cable is shielded, but run through the centre to the front switch inside a thin-wall aluminium tube.
So double shielding if you like.
And if course dual mono, fully symmetrical.
Patrick
Like the mains cable is shielded, but run through the centre to the front switch inside a thin-wall aluminium tube.
So double shielding if you like.
And if course dual mono, fully symmetrical.
Patrick
Are there any links for the W-ONE relay ladder attenuator with 128 steps and 3-digit 7-segment display?
Not available outside China.
Documents only in simplified Chinese.
And we have a customised version, working together with the OEM through a friend in Singapore.
There was one on sale at Swap Meet quite a while ago.
See reference 4 in the pdf.
www.diyaudio.com/community/threads/stepped-attenuator-with-rc-and-display.404695/
Patrick
Documents only in simplified Chinese.
And we have a customised version, working together with the OEM through a friend in Singapore.
There was one on sale at Swap Meet quite a while ago.
See reference 4 in the pdf.
www.diyaudio.com/community/threads/stepped-attenuator-with-rc-and-display.404695/
Patrick
Last edited:
Here some pictures of the unit we have.
Stock version is 50k Rin, has Chinese made Omron G6K relays, and common Gnd for L & R channels.
We have replace the two relay boards (detachable from the MCU board) with our own 4-layer boards
They allow us to use Japanese Omron G6K's, Dale RN55 resistor set for 10k Rin, and separate Gnd's for L & R.
Essentially, we only use the MCU board.
Patrick
Stock version is 50k Rin, has Chinese made Omron G6K relays, and common Gnd for L & R channels.
We have replace the two relay boards (detachable from the MCU board) with our own 4-layer boards
They allow us to use Japanese Omron G6K's, Dale RN55 resistor set for 10k Rin, and separate Gnd's for L & R.
Essentially, we only use the MCU board.
Patrick
Attachments
Someone asked for more details by PM.
Thank you for your interest.
You can asked here. I have no problems with that.
As mentioned in the pdf, the basic modules in the Preamp cones from the F5Pi.
The necessary changes are already explained in the article.
We are using 2SK246/2SJ103 BL, and FQP3P20/3N30 .
These are our preferred devices.
You can most likely also use 2N5459/5462 and IRF610/9610, if they are easier for you to get.
We even published a spice file before :
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7538513
We could have also used 2SK2013/2SJ313, but they are even more difficult to get.
The reason for using higher Idss JFETs for the input stage is that they allow higher value resistors to be used in the feedback network, so as not to load the output stage excessively.
There is no absolute value for bias to follow, rather a matter of taste.
So one can download the spice file, change the device models, and play with the values and different load impedance.
Or just follow the circuit of the BA3 and adjust the gain to suit your needs.
Patrick
Thank you for your interest.
You can asked here. I have no problems with that.
As mentioned in the pdf, the basic modules in the Preamp cones from the F5Pi.
The necessary changes are already explained in the article.
We are using 2SK246/2SJ103 BL, and FQP3P20/3N30 .
These are our preferred devices.
You can most likely also use 2N5459/5462 and IRF610/9610, if they are easier for you to get.
We even published a spice file before :
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7538513
We could have also used 2SK2013/2SJ313, but they are even more difficult to get.
The reason for using higher Idss JFETs for the input stage is that they allow higher value resistors to be used in the feedback network, so as not to load the output stage excessively.
There is no absolute value for bias to follow, rather a matter of taste.
So one can download the spice file, change the device models, and play with the values and different load impedance.
Or just follow the circuit of the BA3 and adjust the gain to suit your needs.
Patrick
Last edited:
The power supply is nothing fancy, just standard Talema toroidal and LM317.
It fits the layout perfectly, and allows complete dual mono, plus separate supply for the auxiliaries.
I am sure other people will have different preferences.
Like R-Core transformers, super regulators, ...., etc.
May only need more space in a larger case.
But as Fran has reported, it is dead quite as is.
Patrick
It fits the layout perfectly, and allows complete dual mono, plus separate supply for the auxiliaries.
I am sure other people will have different preferences.
Like R-Core transformers, super regulators, ...., etc.
May only need more space in a larger case.
But as Fran has reported, it is dead quite as is.
Patrick
For the source select and ladder attenuator, one can just use the standard Relaixed which is fully in the public domain.
www.vaneijndhoven.net/jos/relaixedpassive/
www.tentlabsshop.com/DetailServlet?detailID=1580
It will even fit in the current layout, but we don't like using a SMPS in the preamp.
And the Relaixed will need a milled front panel for the LED 7-segment display.
So we choose to do it differently, as also explained in the pdf.
I was told that the W-ONE is available at AliExpress.
I can't find the link myself, maybe someone can post it here.
But you will have to accept 50k impedance, and whatever resistors are provided.
You can of course also choose to use other attenuator modules like Muses, etc.
www.diyaudio.com/community/threads/muses-volume.322983/
There are also complete source select / ladder attenuator modules on offer on the internet.
So unless you want to build exactly as we did, you don't need anything from us.
If there is sufficient interest for the W-ONE, we can help to contact the OEM and organise a GB for units without the resistors.
We were able to even buy extra MCU boards only, as we use our own 4-layer relay boards.
He is someone more interested in actual technical development, and not the financial return.
And it is only hobby for him outside a full time job.
Very nice guy, a pleasure to work with.
I think I have pretty much covered everything ?
Patrick
www.vaneijndhoven.net/jos/relaixedpassive/
www.tentlabsshop.com/DetailServlet?detailID=1580
It will even fit in the current layout, but we don't like using a SMPS in the preamp.
And the Relaixed will need a milled front panel for the LED 7-segment display.
So we choose to do it differently, as also explained in the pdf.
I was told that the W-ONE is available at AliExpress.
I can't find the link myself, maybe someone can post it here.
But you will have to accept 50k impedance, and whatever resistors are provided.
You can of course also choose to use other attenuator modules like Muses, etc.
www.diyaudio.com/community/threads/muses-volume.322983/
There are also complete source select / ladder attenuator modules on offer on the internet.
So unless you want to build exactly as we did, you don't need anything from us.
If there is sufficient interest for the W-ONE, we can help to contact the OEM and organise a GB for units without the resistors.
We were able to even buy extra MCU boards only, as we use our own 4-layer relay boards.
He is someone more interested in actual technical development, and not the financial return.
And it is only hobby for him outside a full time job.
Very nice guy, a pleasure to work with.
I think I have pretty much covered everything ?
Patrick
Last edited:
I did forget something.
Gerber files from the F5Pi :
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7594526
So you have everything you need to DIY.
😊
Patrick
Gerber files from the F5Pi :
www.diyaudio.com/community/threads/the-f5pi-f5p-voltage-gain-stage-m2-output-stage-perfectly-integrated.406024/post-7594526
So you have everything you need to DIY.
😊
Patrick
I don't know if this link will work, but here is the unit on Aliexpress. I had thought I saw them on eBay as well, but cannot find any now.
https://vi.aliexpress.com/item/1005...f0ec2e&afSmartRedirect=y&gatewayAdapt=glo2vnm
https://vi.aliexpress.com/item/1005...f0ec2e&afSmartRedirect=y&gatewayAdapt=glo2vnm
I‘m always a „chasing man“ behind you and your brilliant projects…..thanks
…soft starting my hifi season now…… 😉
…soft starting my hifi season now…… 😉
Listening tests are currently underway - I will post more information after I get another listening session or two. I like to take a build like this to a few different systems and hear them with a variety of equipment. Listening is such an subjective thing, I think the only way to address all the variables and post something reasonably fair is to compare in a number of systems with a number of people and see what consensus is reached.
First outing is very positive though, comparing to commercial and DIY preamps 😉😉
First outing is very positive though, comparing to commercial and DIY preamps 😉😉