Question for Ale
Question for Ale,
Hi Ale, do you remember how you would have characterised the differences between your balanced differential and your SE 4p1l linestages?
I realise this is likely to be a subjective appraisal though you are very good and do lotsa measuring.
C'mon Los Jaguares
best
tim
Question for Ale,
Hi Ale, do you remember how you would have characterised the differences between your balanced differential and your SE 4p1l linestages?
I realise this is likely to be a subjective appraisal though you are very good and do lotsa measuring.
C'mon Los Jaguares
best
tim
Hi Tim,
Great question and hard one to answer as when I put together the differential stage was a breadboard which didn't survive long. I didn't measure it but remember when I played music through it wasn't as nice as the SE one. The sound was great though, but I felt that my SE version sounded best. Again, I wasn't leveraging the best of the differential stage. I'd build it again, if I were to have the time!
Cheers, Ale
Great question and hard one to answer as when I put together the differential stage was a breadboard which didn't survive long. I didn't measure it but remember when I played music through it wasn't as nice as the SE one. The sound was great though, but I felt that my SE version sounded best. Again, I wasn't leveraging the best of the differential stage. I'd build it again, if I were to have the time!
Cheers, Ale
and thanks for the Jaguares comment! Nothing best for us to play in your lands and improve the game!
Hello
hope someone can tell me this,,,,,can i use a muting relay on output of the 4P1L (connecting the output to ground)
i use caps in output
Best Bjarne
hope someone can tell me this,,,,,can i use a muting relay on output of the 4P1L (connecting the output to ground)
i use caps in output
Best Bjarne
Why not?
If you use resistor to ground in output too, connect parallel the muting relay"s contacts.
If you don't use this resistor, the output capacitor "output" legs potential is undefined (floating).
It's independent of using mute relay or not.
The capacitor's "hot" leg is on the few hundred Volt potential, so charge go trough the output terminal, via the interconnect, to the load (power amplifier) grid resistor or potentiometer. Each charging, recharging current period wandering trough the whole connections.
MUST to use this resistor!
It's independent of using mute relay or not.
The capacitor's "hot" leg is on the few hundred Volt potential, so charge go trough the output terminal, via the interconnect, to the load (power amplifier) grid resistor or potentiometer. Each charging, recharging current period wandering trough the whole connections.
MUST to use this resistor!
Thanks euro21
i will use this resistor after the output cap (100kohm)
and then i will mute the output with my new TDK motor volume--on the remote print there are muting relay
Best Regards
Bjarne
i will use this resistor after the output cap (100kohm)
and then i will mute the output with my new TDK motor volume--on the remote print there are muting relay
Best Regards
Bjarne
have 4P1L Line Stage balanced version? I have not found any schematic, a good friend want to try and his power amp only have xlr input.
This is a good question - I've been thinking about it. I have an old Leak Stereo 20 I want to convert to PP 4P1Ls, for instance, just putting the output stage in the Leak and driving it with a line stage.
What are the options? Not too keen on using a concertina. I have some Lundahl interstages I could rig up for SE into PP. that will be my first experiment. They do actually make a special phase splitter version with better symmetry. I'd be tempted to go with a transformer as a simple, though expensive solution.
What I'd like to know of is a solid state option - I have little knowledge of SS devices so open to others who do and can suggest a good sounding phase splitter design. Doesn't need gain, though a little wouldn't harm.
What are the options? Not too keen on using a concertina. I have some Lundahl interstages I could rig up for SE into PP. that will be my first experiment. They do actually make a special phase splitter version with better symmetry. I'd be tempted to go with a transformer as a simple, though expensive solution.
What I'd like to know of is a solid state option - I have little knowledge of SS devices so open to others who do and can suggest a good sounding phase splitter design. Doesn't need gain, though a little wouldn't harm.
http://www.diyaudio.com/forums/tube...her-semiconductor-substitute-cathodyne-2.html
Here's a thread about a solid stage phase splitter - could be useful. Uses a LND150 and Tubelab has a schematic.
If there's a simple solid state solution it would surely make things easier, and we could use the usual SE line stage designs.
Here's a thread about a solid stage phase splitter - could be useful. Uses a LND150 and Tubelab has a schematic.
If there's a simple solid state solution it would surely make things easier, and we could use the usual SE line stage designs.
New PCBs for a ready to build 4P1L preamp/line stage with LL1671
A while ago I've posted my first single PCB for a high gain 4P1L pre: http://www.diyaudio.com/forums/tubes-valves/190857-4p1l-dht-line-stage-94.html.
I've redesigned using separate PCB for the power supply for more flexibility and easy to build and test. The support holes fit the base of any Modushop case. I've used the Pesante 3U 300mm where the boards will fit perfectly.
This time I've used Triad world series transformers with choice for 115V or 230Vac. All parts from Mouser will cost about $150 with shipping. Besides this BOM from Mouser you'll need the LL1671s, a pair of Coleman and tubes and sockets. Anyone interested I have some boards for sale.
With little imagination these boards can be used to build a 01A pre using LL2745 or adapt a gyrator board for a higher gain preamp.
Best,
Radu
A while ago I've posted my first single PCB for a high gain 4P1L pre: http://www.diyaudio.com/forums/tubes-valves/190857-4p1l-dht-line-stage-94.html.
I've redesigned using separate PCB for the power supply for more flexibility and easy to build and test. The support holes fit the base of any Modushop case. I've used the Pesante 3U 300mm where the boards will fit perfectly.
This time I've used Triad world series transformers with choice for 115V or 230Vac. All parts from Mouser will cost about $150 with shipping. Besides this BOM from Mouser you'll need the LL1671s, a pair of Coleman and tubes and sockets. Anyone interested I have some boards for sale.
With little imagination these boards can be used to build a 01A pre using LL2745 or adapt a gyrator board for a higher gain preamp.
Best,
Radu
Attachments
Nice work Radu! You've put a lot of thought into this! Looks like this would work with the 26 also. Looks like there's plenty of space to put Ale's gyrators in place of the OPTs should one wish to do that.
I've been experimenting with an 01A preamp/line stage and the two best versions are Ale's gyrator and a LL1635/5mA OPT. Both solutions are clearly viable. So is a good plate choke in the case of the 4P1L. The good thing about the 4P1L is it makes a really good driver stage, and I imagine your boards would be really useful for that - like driving a 300b for instance.
I've been experimenting with an 01A preamp/line stage and the two best versions are Ale's gyrator and a LL1635/5mA OPT. Both solutions are clearly viable. So is a good plate choke in the case of the 4P1L. The good thing about the 4P1L is it makes a really good driver stage, and I imagine your boards would be really useful for that - like driving a 300b for instance.
Hi Radu, nice work! Well done. I think it can be very useful board for anyone who wants to adventure on the 4P1L as a line stage. Both LL1660 or LL1635 can be used and the preamp PCB is straight forward.
The supply one is restricted to the triad iron on your BOM, still a great idea if someone has to buy everything.
As Andy said, a BF862/DN2540 gyrator board can be added instead of the output transformers if anyone needs higher gain 🙂
Cheers
Ale
The supply one is restricted to the triad iron on your BOM, still a great idea if someone has to buy everything.
As Andy said, a BF862/DN2540 gyrator board can be added instead of the output transformers if anyone needs higher gain 🙂
Cheers
Ale
Thanks Andy and Ale,
It is flexible enough, and indeed an option for anyone who want a ready to build pre.
There is room for upgrades, but the parts in the signal path are already decent quality.
Line output transformer is agreat option to deal with 4p1ls microphonics and also awesome low Zout and high current capability to drive power tubes of high capacitance loads.
Andy,
The filament Triads are 20VA, so for a 26 one minght need 30VA.
Cheers,
Radu
It is flexible enough, and indeed an option for anyone who want a ready to build pre.
There is room for upgrades, but the parts in the signal path are already decent quality.
Line output transformer is agreat option to deal with 4p1ls microphonics and also awesome low Zout and high current capability to drive power tubes of high capacitance loads.
Andy,
The filament Triads are 20VA, so for a 26 one minght need 30VA.
Cheers,
Radu
