Mine is a 26 preamp - I'm not considering changing to anything else...it sounds THAT good.
Note: a big reason I can get away with the AVC as an output for the 26 even though it has only ~150H inductance is because I have a CCS plate load and I'm using the mu output of the CCS to feed the parafeed circuit, so my effective plate resistance is much lower than usual for the 26. I approximate it to be ~1500R or so.
Thanks,
I remember your built. Really nice.
I may try the CCS with my 26 before trying the 4p1l.
Already use an AVC at the output.
I remember your built. Really nice.
I may try the CCS with my 26 before trying the 4p1l.
Already use an AVC at the output.
Can I use LL1660/25mA as output transformer for 4P1L line stage?
Whether there will be enough inductance for nice bass response?
Whether there will be enough inductance for nice bass response?
That is great 🙂
Thanks!
Is there any other DHT tube with low Rp I can use with this transformer?
Thanks!
Is there any other DHT tube with low Rp I can use with this transformer?
Yes, sure. you could try 10Y or 46. Both good. 71A also though I wouldn't bother too much with that. No doubt a few others too. None may be better than the 4P1L if you use filament bias, since that gives you a significant advantage by not needing a cathode bypass cap. 10Y with filament bias is possible. 46 is a bit heroic.
Approximately:
f-3L = Za/(2*pi*Lp)*(B/(B+1)) where B=ra/Za
given:
Lp=50H, ra=5K and Za=951,750 ohms (47K load reflected in primary when wired 4.5:1)
f-3L=15.8Hz
Just about....
cheers
Ale
Thanks!
But if I want to use 1660 as IT 1:1 for 10Y driving a 300B?
Then Za will be the same or higher?
But if I want to use 1660 as IT 1:1 for 10Y driving a 300B?
Then Za will be the same or higher?
Hello
I use now 4P1L gen3 with Lundahl trafo output
Just for comparison i will like to try it with Caps output..
what do i have to change to use Caps in output ?
i use Salas SShv2 as Highvolt
Best Bjarne
I use now 4P1L gen3 with Lundahl trafo output
Just for comparison i will like to try it with Caps output..
what do i have to change to use Caps in output ?
i use Salas SShv2 as Highvolt
Best Bjarne
First of all how does it sound in comparison to your past project as a pre amp?
If you want to use resistor load you need twice the voltage. It would be helpful
if you could state more details of your psu and mains transformer...
If you want to use resistor load you need twice the voltage. It would be helpful
if you could state more details of your psu and mains transformer...
I'm now using CCS in anode of 4P1L with capacitor on output, much better that resistor in anode 😉
I'm still waiting fro my Lundahl to arrive. I tried custom made output transformer but I was not totally satisfied with the sound so I changed to CCS and capacitor on output.
Resistor vs CCS - with CCS you have so much better resolution and definition, try for your self it is not hard to do it 😉
Resistor vs CCS - with CCS you have so much better resolution and definition, try for your self it is not hard to do it 😉
I have 185 vac on my highvolt trafo...use filmcaps to give dc volt to Salas-- 190vdc to my Lundahl trafo
what shall i use to make it play with caps in output,,or is the volt to low for that `?
what shall i use to make it play with caps in output,,or is the volt to low for that `?
Yes this is expected but is the sound not a little too clinical whit CCS?
I will propably go whit the lundahl...