Okay, thanks. Maybe I try the dedicated M2x Aksa Lender, it's just about 20 smd-parts 🤔
Any thoughts to the power supply? https://www.tme.eu/at/en/details/rp...xDEZitXJmf5vfvNAnNvhYaAaAvd9EALw_wcB&brutto=1
Any thoughts to the power supply? https://www.tme.eu/at/en/details/rp...xDEZitXJmf5vfvNAnNvhYaAaAvd9EALw_wcB&brutto=1
If the LuFo uses +28VDC and the BA2018 needs a +/- supply, how are you going to generate that? Separate power supply?
Yes, if I choose the BA as FE. But I'm still not sure which FE I choose...
Some slow progress after restarting the project, and some missing parts (missing, because not available and missing, because ordered and paid, but only delivered 4 pieces instead of 6... 7 months ago, so it's too late now).
@xrk971 could you please help re the following "issues":
@xrk971 could you please help re the following "issues":
- for the 22pF there is a "normal" (upper side) and an smd soldering position (under side) on the board - is this an option or a requirement? I soldered the normal one with 22pF/500v.
- are there recommended preset values for the trim pots?
Hi Plott,
You can use one or the other on the 22pF caps. No difference sonically that I can hear. Pot position - leave in middle as that was where it was sized for and adjust up or down to achieve correct voltages and currents. Be sure to have several DMMs installed to monitor voltage setpoints and currents across resistors initial during turn-on. Have a finger on the shutoff switch in case you detect excessive voltage or current. Excessive is current above 5A and loud hum from trafo, smoke or smells. You will know in 2 seconds. And if it gets past 2 seconds stand back for at least 1 minute to make sure electrolytic caps are good and don’t explode if improper polarity or “dud” infant mortality. Wear safety goggles.
You can use one or the other on the 22pF caps. No difference sonically that I can hear. Pot position - leave in middle as that was where it was sized for and adjust up or down to achieve correct voltages and currents. Be sure to have several DMMs installed to monitor voltage setpoints and currents across resistors initial during turn-on. Have a finger on the shutoff switch in case you detect excessive voltage or current. Excessive is current above 5A and loud hum from trafo, smoke or smells. You will know in 2 seconds. And if it gets past 2 seconds stand back for at least 1 minute to make sure electrolytic caps are good and don’t explode if improper polarity or “dud” infant mortality. Wear safety goggles.
Hi
Can someone tell me which MOT i would need for this amp.
I believe that it has a precise model number. I’d like to avoid ordering the wrong stuff.
Maybe a pic would help.
Thanks
Eric
Can someone tell me which MOT i would need for this amp.
I believe that it has a precise model number. I’d like to avoid ordering the wrong stuff.
Maybe a pic would help.
Thanks
Eric
Depends on how pricey you want to get. There are Hammond and Lundahl retail options that fit the bill. Cheap MOTs are also an option. The thread has examples.
#803 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6874848
#839 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6999580
#414 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6699665
#840 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6999607
#803 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6874848
#839 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6999580
#414 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6699665
#840 https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/post-6999607
Perfect, thanks!
Actually the MD-803 seems to come in different flavour, would the AMR-1 be ok ?
Eric
Actually the MD-803 seems to come in different flavour, would the AMR-1 be ok ?
Eric
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Do you believe that the eBay seller will actually measure the DCR ? It’s ok I’ll look through the thread one day, I know the information is there I’ve read it a while ago. Something specific about a 4 letter code in the right lower corner of the nameplate.
Hi there,
I apologize if the question has been posted before (I did not read the whole thread).
Did anyone compare Lufo to MoFo?
But, a scaled down Lufo? I mean, I have a "standard" Mofo (19V psu, 1.7 amp bias). Now, if I add just a Lu jfet, but keep the same PSU and the same bias (19V, 1.7A) and only one Mosfet (as in Mofo), what would be the difference in sound quality?
Did anyone make such "apples to apples" comparison?
I would like to know because I would like to know if it's worth upgrading a Mofo to almost a Lufo...
Thanks
I apologize if the question has been posted before (I did not read the whole thread).
Did anyone compare Lufo to MoFo?
But, a scaled down Lufo? I mean, I have a "standard" Mofo (19V psu, 1.7 amp bias). Now, if I add just a Lu jfet, but keep the same PSU and the same bias (19V, 1.7A) and only one Mosfet (as in Mofo), what would be the difference in sound quality?
Did anyone make such "apples to apples" comparison?
I would like to know because I would like to know if it's worth upgrading a Mofo to almost a Lufo...
Thanks
Another possibility for those who live in Europe and cannot find 110V MOTs anywhere around:
Connect two identical 220V MOTs in parallell. Yes, it will be double the cost (I paid 5 euro for each on the junkyard, huh), double the weight, 2xSpace, half the inductance...(ouch)
But, half the DCR! And there will be plenty of inductance left, even like that...
Good question. Based on my listening impressions, I felt that the LuFo sounded more clear and had more bass authority. The clarity comes from having less harmonic distortion. The voltage is less of an issue if we compare the FFTs at lower output voltage well within supply rail. These are not at same exact conditions but you will see that LuFo is lower THD by maybe 20x less. Bass authority is improved because of the topology as it is a master JFET driving slave cascode MOSFETs.
Here is LuFo at 2.83Vrms into 10ohms:
Here is MoFo at 2Vrms and 4Vrms at 8ohms, 2.83Vrms would be somewhere in between:
Vix is looking to utilize the MoFo psu which is lower voltage and bias current than LuFo. Would the above LuFo measurements be accurate in this case?
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1.7A and 19v is well below the point at which current or voltage limit is an issue which is why I only compare at 2.83vrms. The MoFo should be able to do about 11w. The LuFo would have even more advantage at higher power but at lower powers the comparisons are not current or voltage linited and comes down to intrinsic distortion.
One would hope that going from a single transistor to a a more complicated two transistor cascode topology would yield better performance.
One would hope that going from a single transistor to a a more complicated two transistor cascode topology would yield better performance.
I have been measuring 6 new LD1014D and they all show 0 ohm between drain and source,is that how it should be?
It’s a depletion mode JFET. Apply a voltage and it should pinch it off. It conducts normally with nothing on the gate. Acts very much like a variable resistor where voltage increases resistance.