If anyone needs LuFo PCBs as described here:
LuFo Amp - 39w SE Class A from 28v Rail
You can order your own from the Gerbers provided or put your name here in the GB interest list and I will order them and make them available in my shop for a nominal cost.
Boards sold as pairs in a panel.
Please add your name, number of boards (pair), and country below.
For example:
JohnAmpBuilder / 1 pair / USA
LuFo Amp - 39w SE Class A from 28v Rail
You can order your own from the Gerbers provided or put your name here in the GB interest list and I will order them and make them available in my shop for a nominal cost.
Boards sold as pairs in a panel.
Please add your name, number of boards (pair), and country below.
For example:
JohnAmpBuilder / 1 pair / USA
Attachments
Last edited:
X,
Thought I would put down interest as I have a bunch of MOT's laying around and a bunch of LU1014D. (4 more microwaves just arrived to tear apart). Lots of fun!!
Plott / 1 pair / Austria
Kokanee / 1 pair / Canada
Thought I would put down interest as I have a bunch of MOT's laying around and a bunch of LU1014D. (4 more microwaves just arrived to tear apart). Lots of fun!!
Plott / 1 pair / Austria
Kokanee / 1 pair / Canada
You are doing great if you have all these MOTs!
You can make MoFo’s and LuFo’s till the cows come home.
They make great headphone amps too. Very quiet.
You can make MoFo’s and LuFo’s till the cows come home.
They make great headphone amps too. Very quiet.
Hi xrk
Firstly, kudos for contributing a further innovative project 😎
(I continue to be snowed under, designing a complex makeover for my house) … in the few in-between times, I’m deciding what project to put in the post-design pipeline -
the PCBs
I’m guessing they’ll be ordered after JPS64 adds the pot to adjust the LU1014’s Vgs? and with provision for a cap ( ~10 uF) to the wiper?
(and unlikely/ possibly if there were any further yet-to-be identified refinements)
Are they are/ will be compliant with the store’s UMS cases?
What’s the possibility that the GB could optionally include
either
- the Lender daughter board (in the works)
- or a M2X format front end?
You’ve previously mentioned the Lender and the 2/3 others which can definitely provide enough vpp output. While all are ~ class A so ~ broadly similar, the one with the particular sound flavour which most appeals to me is the Haiku. I understand it can’t provide 100% of the ideal input.
But, keeping it simple, ie without modifications, a pair of Haiku
- Balanced
- Biased up a little
Approx ~ vpp would that be likely to output, and what ballpark output watts would we get? (within 10 wpc would be fine)
My thinking: if using (say) the Lender we can get to 100 watts, while a pair of biased-up Haiku would limit that (for argument's sake) to an output of 70 - it’s still a healthy number. And the drop in potential maximum dB/ headroom would only be around 1 dB
And if as you did, we use a generously specced 600 VA choke, the other arguably more important quality of ability to handle a succession of low bass transients - I’d think should still be healthy. Leading to …
final thought. at one point (one of the related threads) you said that a/ the choke might be in a GB.
In this amp, a good choke seems at least as important to the ability to handle dynamics, certainly more unique to the overall project, than the ideal input-side volts. Yes, they’re heavy-ish. But your description of the specially specced unit you got - sounds like it’s a better option than one from microwave or a Hammond. Seems a logical/ fundamental/ companion GB
HTH
Firstly, kudos for contributing a further innovative project 😎
(I continue to be snowed under, designing a complex makeover for my house) … in the few in-between times, I’m deciding what project to put in the post-design pipeline -
the PCBs
I’m guessing they’ll be ordered after JPS64 adds the pot to adjust the LU1014’s Vgs? and with provision for a cap ( ~10 uF) to the wiper?
(and unlikely/ possibly if there were any further yet-to-be identified refinements)
Are they are/ will be compliant with the store’s UMS cases?
What’s the possibility that the GB could optionally include
either
- the Lender daughter board (in the works)
- or a M2X format front end?
You’ve previously mentioned the Lender and the 2/3 others which can definitely provide enough vpp output. While all are ~ class A so ~ broadly similar, the one with the particular sound flavour which most appeals to me is the Haiku. I understand it can’t provide 100% of the ideal input.
But, keeping it simple, ie without modifications, a pair of Haiku
- Balanced
- Biased up a little
Approx ~ vpp would that be likely to output, and what ballpark output watts would we get? (within 10 wpc would be fine)
My thinking: if using (say) the Lender we can get to 100 watts, while a pair of biased-up Haiku would limit that (for argument's sake) to an output of 70 - it’s still a healthy number. And the drop in potential maximum dB/ headroom would only be around 1 dB
And if as you did, we use a generously specced 600 VA choke, the other arguably more important quality of ability to handle a succession of low bass transients - I’d think should still be healthy. Leading to …
final thought. at one point (one of the related threads) you said that a/ the choke might be in a GB.
In this amp, a good choke seems at least as important to the ability to handle dynamics, certainly more unique to the overall project, than the ideal input-side volts. Yes, they’re heavy-ish. But your description of the specially specced unit you got - sounds like it’s a better option than one from microwave or a Hammond. Seems a logical/ fundamental/ companion GB
HTH
Plott / 1 pair / Austria
Kokanee / 1 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
Thanks XRK!
Kokanee / 1 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
Thanks XRK!
Hi Otto,
I also personally like the sound of the Hakuin perhaps the most of all the preamps. I will post the Aksa Lender and OPA454 front ends. They also need some minor tweaking. The Aksa Lender actually had a major revision after Vunce found out that the DCDC converter we were using was not able to make 55v. We had to go with a different chip completely. There was actually a lot of behind the scenes development work on those front end boards.
So we need to wait for JPS64 to finalize the layouts. They take quite a lot of time and I am grateful to JPS64 for all that he does for us.
The Hakuin topology could be used as a conventional preamp to drive the OPA454 and that will impart it with the flavor of SE Class A front end.
However, keep in mind that the SuSyLu and LuFo itself has that built in to the output stage already.
The custom inductor is certainly a critical and enabling piece of tech for this amp. I am not sure I want to deal with shipping a pair of 11lb chunks of iron. Especially overseas. Let me think about it. The other issue is that if I make a commercial amp out of this, the inductor is the key ingredient.
There might be a HV version of the Hakuin based on all BJT parts with a crazy 250v rail to allow +/-80Vpp.
Good to see a little more interest in the LuFo PCBs.
I also personally like the sound of the Hakuin perhaps the most of all the preamps. I will post the Aksa Lender and OPA454 front ends. They also need some minor tweaking. The Aksa Lender actually had a major revision after Vunce found out that the DCDC converter we were using was not able to make 55v. We had to go with a different chip completely. There was actually a lot of behind the scenes development work on those front end boards.
So we need to wait for JPS64 to finalize the layouts. They take quite a lot of time and I am grateful to JPS64 for all that he does for us.
The Hakuin topology could be used as a conventional preamp to drive the OPA454 and that will impart it with the flavor of SE Class A front end.
However, keep in mind that the SuSyLu and LuFo itself has that built in to the output stage already.
The custom inductor is certainly a critical and enabling piece of tech for this amp. I am not sure I want to deal with shipping a pair of 11lb chunks of iron. Especially overseas. Let me think about it. The other issue is that if I make a commercial amp out of this, the inductor is the key ingredient.
There might be a HV version of the Hakuin based on all BJT parts with a crazy 250v rail to allow +/-80Vpp.
Good to see a little more interest in the LuFo PCBs.
Hi xrk,
altough I already ordered my superheavy chokes it would be interesting to compare how the amp sounds with your custom built choke vs. with one of the readily available chokes (f.e. with the Hammond 100 mH).
altough I already ordered my superheavy chokes it would be interesting to compare how the amp sounds with your custom built choke vs. with one of the readily available chokes (f.e. with the Hammond 100 mH).
I’m checking to see if it’s possible to get a few of the custom chokes for DIY members whom are interested.
Plott / 1 pair / Austria
Kokanee / 1 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
Kokanee / 1 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
Plott / 1 pair / Austria
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
How long (dimension) are the latest version? I'm also interested in your front end gain/power stack. Do you expect to provide those as boards or RTR? Thanks.
Boards are 250mm long. You can see the dimensions in the Gerber zip file or look at the PCBA stuffing diagram. There is a 10mm edge distance that needs to be added from the bolt to the edge.
I will also offer the front end board but so far only the OPA454 had been tested and the Aksa Lender one needs to be tested. There is a minor layout error that needs to be corrected in the PSU sub board and that can be released. I do not plan to offer it ready to run. Just not enough interest.
The latest schematics, BOM, and Gerber files are here:
LuFo Amp - 39w SE Class A from 28v Rail
I will also offer the front end board but so far only the OPA454 had been tested and the Aksa Lender one needs to be tested. There is a minor layout error that needs to be corrected in the PSU sub board and that can be released. I do not plan to offer it ready to run. Just not enough interest.
The latest schematics, BOM, and Gerber files are here:
LuFo Amp - 39w SE Class A from 28v Rail
Resistance is futile 🙂 , sign me up too
Plott / 1 pair / Austria
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
dBel84 / 1 pair / USA
Plott / 1 pair / Austria
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
dBel84 / 1 pair / USA
Plott / 1 pair / Austria
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
dBel84 / 1 pair / USA
Skip Pack / 3 pair/ USA (choke interest)
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
dBel84 / 1 pair / USA
Skip Pack / 3 pair/ USA (choke interest)
Plott / 1 pair / Austria
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
dBel84 / 1 pair / USA
Skip Pack / 3 pair/ USA (choke interest)
VeightTripleDivision / 1 pair / Latvia (choke curiosity, no idea how affordable it is tho)
Kokanee / 2 pair / Canada
spiggs / 2 pair / USA
pfdavid / 2 pair /USA
jonboylaw / 1 pair / UK. (interested in Chokes as well if shipping reasonable).
dBel84 / 1 pair / USA
Skip Pack / 3 pair/ USA (choke interest)
VeightTripleDivision / 1 pair / Latvia (choke curiosity, no idea how affordable it is tho)
Hi Folks,
You can place your pre-order for the LuFo boards in my shop now. Boards are sold per pair in a panel for $45. 1.6mm thick x 2oz copper with HASL finish, green solder mask.
Pre-order Lufo Class A Amp PCB | Etsy
Regarding the custom choke. I have to do some research. These are heavy items and not easy or inexpensive to ship so I am not sure if I want to burden myself with the headaches that go with it.
I expect to be shipping you the boards in 2-3 weeks.
You can place your pre-order for the LuFo boards in my shop now. Boards are sold per pair in a panel for $45. 1.6mm thick x 2oz copper with HASL finish, green solder mask.
Pre-order Lufo Class A Amp PCB | Etsy
Regarding the custom choke. I have to do some research. These are heavy items and not easy or inexpensive to ship so I am not sure if I want to burden myself with the headaches that go with it.
I expect to be shipping you the boards in 2-3 weeks.