EL84 Amp - Baby Huey

[surfstu]

Thanks Bas, maybe I will start looking out for a cheaper choke option....

GZ34, any other tube recitifiers that you could recommend that could handle the current demands of the babyhuey?

[Bas Horneman]

Hi surfstu, I am using a 5R4. Basically anything that can handle 200mA.

Verstuurd van mijn GT-N7000 met Tapatalk

[surfstu]

Thanks Bas, if you have a schematic available for your psu with the 5r4 I would love to see it....

Stuart

[Soonerorlater]

Originally Posted by surfstu

will the choke make a noticeable difference? I'm planning on a similar supply for the early ecl86 baby huey design but the Lundahl chokes are near £150!

and why does no one use the GZ34 for rectification? I only ask because I already have the octal socket for it in my chassis....

Hi Surfstu,

I got mine from here


HT Smoothing Chokes

Also keep an eye on Ebay

[surfstu]

Thanks Soonerorlater,

would I need a choke greater than 100mA? I presume so...

seen a nice vintage 17H 160mA that i could buy

would that be too little?

it will be running into 4 x ecl86 PP UL amp with approx 30mA running through each tube

[Soonerorlater]

Current wise you should just about be OK for 4 X ECL86's.

seen a nice vintage 17H 160mA that i could buy

IIRC the choke spec was 5-10H. Perhaps you could model your power supply in Duncan to see how the increase in inductance changes things.


For me, vintage means "used". Of course if this vintage choke is dirt cheap.............

[surfstu]

Thanks, I,ve just started using PSUD2 as of yesterday...

was a little confusing for a noob but I,m getting there... I don't think the 17H should be a problem, just hope that 160mA is ok.

There is also a nice quad 2 choke on the same site for sale, kinda like the idea of that, just need to find some info on its rating...

Just using PSUD2 now to try and workout if I can use the spare heater filament supply (6.3V) and convert it to 12Vac or 12vdc, to power some chinese VU Meters tha i just bought. The driver board requires either ac or dc at 12v.

Stu

[M Gregg]

Has anyone built,

the amp in post 1261/1262 of this thread?

And used off the shelf power Tx and good OP Tx?



Regards
M. Gregg

[Soonerorlater]

Originally Posted by gingertube

The rest of the Jessica Amp for info

Note this was a 6V6 + 6SL7 version.

Cheers,
Ian

Page 127

[Drewaudio]

Hi all,

Just a quick update for those that are interested....

Well I finally finished the main amp today and fired it up with 6V6's (my plan is to use 6F6's). Wow!...this little amp sounds just amazing! It's way better than any amp I've previously built and it's dead silent with no signal (I measure 0.0001mv rms hum at the speaker). OPT's are custom electraprint's 20 watt 10k to 6 ohm.

I deviated from the PSU slightly. The negative supply uses a voltage doubler fed by the two 9v windings on a toridal to get -48v. This allowed me to wind a heater winding on the torid for the 6sl7's.

The only problems so far is that the 6v6 bias pots (50k) are fully wound and I can't drop the current below 42ma (they started off at about 100ma at very first power on!!!). The balance pots (100R) are also fully wound to one side and only just come close to balancing....

I'll take some more measurements over the next few days but the sound is just fantastic! Thanks Gingertube!