Feltron-Zeissler still exists in Troisdorf south of Cologne(Köln) on the east side of river rhine (also called the "weird side" - for a reason ?)
Price is DM>>€ + inflation iow 100Euro+
...I really have to come "to that beach of yours" and trace your steps...
Do you run up&down the beach with this homemade metal detector ???
(company is called BAKAtronics ... which clearly fits me (us?) )😀
Final words:
I need to build MONOBLOCKS (as Glen put so nicely)
Have a nice working day folks...
that Fischer case looks like the solution to most DIY needs!
I suspect that the price kills the appeal? How much was it?
I suspect that the price kills the appeal? How much was it?
vrun said:
Oops, you shouldn't have read that thread, i'm much obliged to the mods for removing it.
Seems you're close with your inflation rate estimate, Bürklin currently lists a comparable Feltron 2008 type at ~60-70 € +Elfenreiter's Märchenst. (H159.210)
Here's an online dump store that seems to have identical ones :case
At a 150km distance a bit far from me to just drop by for a look-see though.
(übrigens, didn't Pollin have single secondary 24Vac transformers in a 60VA or bigger size ?)
I'd look rather silly with a metal detector around my neck at the FKK beach, how about some SAND ?
It's not the size of the Fischer KRG case but the heatsinks which will be a dissipation problemo.
In horizontal rib position i'd estimate them to be close to 2C/W, the interior height of just a little over 35mm also makes it tricky.
Variac,
Compared to what Fischer charges for heatsinks
...it's rather moderate 50 €
...quality&finish is "original Fischer" - so for me there was (too) little hesitation when I was offered a small discount.
MOF however the dimensions are a bit small for general purpose use - see my link above.
I haven't
...so you(we) do get it from different sides 
Best.Nr. 300 499 4,95 EUR ...but I've got something BIGger
I'd _feel_ silly without oneI'd look rather silly with a metal detector around my neck at the FKK beach...
No. 4806 ? As you've looked at the data you know there is none.
I planned to use my "two 30W halogen bulbs in a copper tubing" test fixture and just give it a try...
vrun said:
Hi Reinhold.
Testing out the heatsinks before going ahead with the complete construction would be a good idea.
The amp dissipates about 30W at idle, so any heatsink rated at ~2degc/W is going to get rather toasty.
It's a pity that the heaksink fins run horizontally instead of vertically.
Cheers,
Glen
spind said:
You're welcome.
That means MJL21193 should have his soon (another Canadian)
Cheers,
Glen
OK guys, I finally got around to doing the promised testing with lower values for the compensation capacitor.
I tried 82pF and 68pF. With 68pF the nice and clean 100kHz squarewave step response was lost due to the increased slewing of the VAS coming up against the bandwidth limitations of the output stage.
With 82pF, under heavy output current demands (4R // 1uF) some very small bursts of HF oscillation were evident coming out of severe clipping.
Going back to 100pF, under these adverse operating conditions, everything was perfect again, so it looks like 100pF is the way to go. The BOM will of course remain unchanged.
Cheers,
Glen
I tried 82pF and 68pF. With 68pF the nice and clean 100kHz squarewave step response was lost due to the increased slewing of the VAS coming up against the bandwidth limitations of the output stage.
With 82pF, under heavy output current demands (4R // 1uF) some very small bursts of HF oscillation were evident coming out of severe clipping.
Going back to 100pF, under these adverse operating conditions, everything was perfect again, so it looks like 100pF is the way to go. The BOM will of course remain unchanged.
Cheers,
Glen
jacco vermeulen said:
Very pretty valve mount. 🙂
I'd still mount a heatsink tab on the VAS transistor. Dissipating 1W the TO-126 does get pretty toasty.
MJL21193 said:
That's a bit of a worry. Spind (in Canada) has his already and yours went out in the same batch. Do you reside in a slower hillbilly part of the country? 😀
If they don't turn up I'll mail another pair and hike the price up for the remaining 18.
Cheers,
Glen
G.Kleinschmidt said:
Yes, master.
Even a regularish heatsink fits, only R1 needs a bit of a bender.
The idea is to have the valves protrude out of the case for about 1 1/2" and the covers conveniently hide the real identity of the Russian Y-Offs.
(make the takers of the last 18 squeel.)
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G.Kleinschmidt said:
Sorry, I was checkin' da mash for de next batcha moooonshine. Purty ripe! Gotsta keep one stepa head a dem revenuers!
Dang it! Where did I put my shotgun?
You send me dem boards sonny?
I'm not too worried yet. Give it till the end of this week and we'll see.
My spell checker blew a gasket on this one. 🙂
Looks nice MJL21193 🙂
Is thoose heatzinks enough? I have to do some cutom style heatzinks as well. I havent decide yet how. I'm looking for a box that I don't have to pay anything for, in the meantime 😉 The Aluprofiles I got for free from my work. I have to saw them to the right size myself though.
And the transformers and the MPSA92 .... hrmm I have painted windows on our house lately
But also done some research on my sequenced blinker on my Cougar. It works so so and I will maybe do a u processor project of it .... but after this amp is done.
Is thoose heatzinks enough? I have to do some cutom style heatzinks as well. I havent decide yet how. I'm looking for a box that I don't have to pay anything for, in the meantime 😉 The Aluprofiles I got for free from my work. I have to saw them to the right size myself though.
And the transformers and the MPSA92 .... hrmm I have painted windows on our house lately
But also done some research on my sequenced blinker on my Cougar. It works so so and I will maybe do a u processor project of it .... but after this amp is done.
MJL21193 said:
Nice! 🙂
Not a lot of surface area though, so it might still get reasonably warm.....
The fins of my 300mm X 75mm X 48mm heatsinks reach about 15 deg. C above ambient directly opposite the mounting bracket.
Cheers,
Glen
Radioman62 said:
Thanks,
It's not done yet. Stay tuned...🙂
G.Kleinschmidt said:
Thanks, made to look cool, but get red hot
No, there's more to it. I want these for the "sides" with a bottom plate and a top plate that is 3/16" aluminum and will join with these. This will increase dissipation.
As you have already done the hard part (design, layout and board), I will concentrate all of my efforts into the chassis.
I'm going for a different look here...not retro anymore. 😉
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