K50 or K60?

[M Fowler]

http://www.parts-express.com/pe/showdet ... er=020-658

http://www.tubeampdoctor.com/en/shop_Ca ... acitor_509

[azatplayer]

haha, i did see them Mark. Ive used some TAD's before, were ok i guess, the gold comes off so easy tho makes them a little cruddy looking.
Im sure the rubys are the same cap.
Im trying to figure a way of soldering the snap in caps in, that LOOK nice, and are serviceable. The spec on the panasonic stuff is off the chart.
After seeing dynamans build in Daves post of board material, its got me thinking hard on how to emulate that fine beauty!

[M Fowler]

There are other sources but not sure about shipping to down under so I didn't post those.

The only other source I have seen were surplus centers which are usually the snap caps.

[soma_hero]

antique electronic supply has several options. C-ET220-350 is 220uF/350V. They also stock illinois 220uf/300V

[Zippy]

Nice! K50 with sozos and beyschlags it is! Mark I've ordered one of Danas nice switches for it too, and I'm gonna vvr it to get down to that sweet 400v range more than going lower, I got lo power amps for that.

If you are doing a scratch build, why not spec the power trannie for the desired voltage rather than adding more parts?

[azatplayer]

Haha, i hate more parts than needed!
I built a K60 around a chassis i had on hand, that amp runs 400V and sounds pretty amazing, did a side by side with an express last night, it has more headroom, volume and authority than the express, sounds pretty similar tho.
The express had more sparkle and that great compression. Both killer amps.
The reason im doing a K50 is cos i have not done a clone before, that is followed the build to the letter, i mean to do that on this build. BUT adding the VVR for a little versatility also using Danas footswitch as well.
I like what my amp is doing at this voltage, hence why i stated the use of the VVR. CHeers!

[Clyde]

I just finished a K50, however I used K60 transformers. I believe the PT is the same but the primary impedance of the K60 is 5.2k. I had a little input and advice from Mark (Thanks!) to get going with it. I added trem to it and a fat switch and had originally wanted Dana's VVR and switching system but too many delays in getting the parts had me changing course. My customer didn't want the VVR anyhow and now that it's built, I don't mind the toggle for fast and gradual either. The fat switch kind of takes up the lost ground between. The amp sounds spectacular, very loud, very clean/dirty, super dynamic and would be great for live performance. I like it much better than the Express I did a few years ago. I'd like to try one at 4.8k and see what difference there is.

[M Fowler]

I've built two K60's so far and they are great amps.

Got a chassis now so I can start on a K50 and see how much different the two amps are.

I like my Express as well but they are different amps for sure.

I will put the preamp caps on the tone board again and the main filter caps by them selves rather then the traditional cap board under/over style of the original.

Still need to install Dana's foot switch in my first K60.

[stiltamp]

Is this one a Komet too?

[francospence]

Yet another fine amp that will end up on the shelf of discarded chassis's.....i give you a month Azatplayer I'll say it again, your a Rocket guy, and ive heard you play every fine amp you've built!

[hans-jörg]

Here is how Allyn did his K50 and he knows how to build these amps.

Yeah it would be a good idea to go with MF and Mallory 150's I believe.

Sozo would be good as well if you can get them. Had to rub that in.

like Dave said K50 4k8 OT and solid state rectified.

hello,
what a kind of switch is this!? Footswitched Fast/Gradual?

Ist this a K50 with Cathode follower?

Is there a Scrach, or a plan available from Allyn built?

Hans-Jörg

EDIT: just a"small" question more: I built mine up with 6v6 becaus of ma Tranny wich gives me 310 VDC after rectifying. Far away from a Komet. But what Raa I would need with this constellation? Around 5k on the OT? or 8k, what I have now. Its an universal Hammond 125E.

[LeftyStrat]

Is this one a Komet too?

That's basically the Express/Liverpool preamp with the addition of the Fast/Gradual switch from the Komet.

[hans-jörg]

[quote="hans-jörgEDIT: just a"small" question more: I built mine up with 6v6 becaus of ma Tranny wich gives me 310 VDC after rectifying. Far away from a Komet. But what Raa I would need with this constellation? Around 5k on the OT? or 8k, what I have now. Its an universal Hammond 125E.[/quote]

Hi, any suggestion?
I know that my DC level is quite low (but I changed my dropping line, so I have quiet enough on the V1 - V3), but for 6v6 its enough. And when I´m not wrong 2 6v6 requires a 8k Raa with >300VDC.

Hans-Jörg

EDIT:
ok, I found it. Its ok with 8k.

[greekie]

Who has the schematic? I got the 60 and I'd like to see the differences between that one and the 50 that everyone keeps recommending

[hans-jörg]

Who has the schematic? I got the 60 and I'd like to see the differences between that one and the 50 that everyone keeps recommending

Hi,
I hope I can help you:
the voltage divider (220k/330k) is gone, only 330k to ground (express has 150k there) and the 4th, not used stage, becomes a cathode follower (classic, with 100k cathode tp ground), no rectifire tube but solid state rectifying (that means you have to change the electrolyt C to that kind of rectifying with 100µF at first place instead of 20µF (I think thats all Express values there now in the K50).
hopefully thats all.

Hans-Jörg