Danelectro Cadet tubes

capnjuan

Gone But Not Forgotten
Gone But Not Forgotten
Joined
Nov 29, 2006
Messages
12,952
Reaction score
4
Location
FL
Sharptone said:
After bringing it home I opened it and found out that it was a a line-operated transformerless amp. (Arrrgh) The tube lineup consists of 1 rectifier tube(35W4), 1 preamplifier tube(12AX7) and 1 power output tube(50C5).... I will definitely replace all electrolytics(e.g: # 4 and 6 on the photo) Can you please tell me what types of capacitors are # 1, 2, 3, and 5 on the photo? Do I need to replace them?
Hi Sharptone; before I forget, you might consider taking your original pics, reducing them in size to something 640 X 480 and knocking down the resolution ... they load v..e...r....y s.....l......o.......w.........l...........y

Anyway:
1. Electrolytic; polarity must be observed.
2. Mylar
3. Mylar
5. Polycarbonate

All of them should be replaced and the type of material isn't important. I suggest Mallory 150s; a well-made, moderately-priced, commonly available make of metal film capacitor. #4 is an electrolytic and I suggest Sprague for it; common value, inexpensive. #1 may be a pain to find; small value for the type but if you couldn't find .01 but found something between .02 - .05, I don't think it would make a critical difference.

Welcome! J
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
Thanks capnjuan for the welcome and for the info...exactly what I needed.

Sorry for the large photo, its now fixed.

I will now look for a supplier...great!

If someone knows the brand name of the amp I would be very interested to know.

One more thing, I will also add some vintage speaker cloth to make it look like it should.

Thanks for your help.
 

danerectal

Senior Member
Joined
Aug 30, 2007
Messages
1,526
Reaction score
0
Location
Fargo, North Dakota
Sharptone said:
If someone knows the brand name of the amp I would be very interested to know.

That bears a striking resemblance to my Harmony 420. Mostly in the control layout, but there it looks like they were punched with the same die. The biggest reason to doubt any link would be the fact that the 420 was built in Chicago, IL. Even some of the components look similar. I'll see if I can get some pics of it for comparison sake, though whether it will help or not remains to be seen.
 

capnjuan

Gone But Not Forgotten
Gone But Not Forgotten
Joined
Nov 29, 2006
Messages
12,952
Reaction score
4
Location
FL
Sharptone said:
I will now look for a supplier...
Hi Sharptone and thanks for the pic fix.

Sources for the Mallory 150s
Antique Electronic Supply click Capacitors / Mallory
Hoffman Amps Capacitors, first ones listed are Mallory 150s. You might also browse Hoffman's tech BB; as good as there is on the web.

That .01uf/500V is going to be tough; low value/high voltage electrolytics are a thing of the past. Suggest you work around it, see if you get the amp running correctly, check the voltage on that cap and see what it's looking at. It's at least possible that they were more interested in the value and put in whatever caps they had irrespective of voltage rating. If the voltage to which it's exposed is considerably less than 500V ... well ... that would be called getting lucky. Good luck with your project! John
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
Hi Dane - This is very interesting. If you do have pics, please do post them.

capnjuan - Thanks for the headsup. I will sure look at both suppliers suggested.
I'll let you know if I find the 0.01 uF/500V electrolytic.

Cheer!
Rog
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
You were right capnjuan, I had no luck finding a 0.01 uF/500V electrolytic.

Could it hurt anything if replace it with a Mallory 150's with a value of 0.01 uF/630V?

If it doesn't work I can always put the original back.

Also, I could not find a 25 uF electrolytic replacement but I found a 20 uF/500V(Sprague Atom electrolytic).

Would that be close enough?

Thanks,
Rog
 

capnjuan

Gone But Not Forgotten
Gone But Not Forgotten
Joined
Nov 29, 2006
Messages
12,952
Reaction score
4
Location
FL
Hi Rog; easy part first; yes, the Sprague 20uf / 500V will be fine ... the uf value in that cap isn't critical. The .01 ... that's another matter. No; if it's an electrolytic and particularly if the (-) end is grounded, it needs to be an electrolytic. I really don't understand how these 'line' amps work except to say that they are usually only 2-3 watts or so and if so, I don't know where the high voltage is that warrants the cap's rating. T'were me, I'd probably work around it - there's no reason to believe it's bad -, fire up, and see what happens.

You can probably find that cap but it will be an audio/stereophile-grade oil-filled piece that will run $15 - $20. Alternatively, you can research Harmony and Dano schematics and see if you can find any that have a cap like that one; see if you can figure out what the cap does ... and how much voltage it's supposed to withstand. Like I said, they might have just had some laying around ... who cares if it's more than enough ... the issue is usually whether it's voltage rating is too low ... not too high.

John
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
John - After reading your last post I made a quick search and found this "Sequa Aluminum Foil Paper In Oil .01uF/600VDC Audio Signal Capacitor" for $5.00 each.

Would this be appropriate?
These are not polarized are they?

It goes from the pin 6(12AX7 plate 1) to pin 2(50C5 grid 1).
My guess is that it is a coupling capacitor between the tubes.

Thanks,
Rog

Here is a pic of it:
http://angela.com/sequaaluminumfoilpaperinoil01uf600vdcaudiosignalcapacitor.aspx
sequa01ufcap600vdc.jpg
 

capnjuan

Gone But Not Forgotten
Gone But Not Forgotten
Joined
Nov 29, 2006
Messages
12,952
Reaction score
4
Location
FL
Sharptone said:
It goes from the pin 6(12AX7 plate 1) to pin 2(50C5 grid 1). My guess is that it is a coupling capacitor between the tubes.
Hi Rog; this is working out well; I win the prize for cynicism ... ("... they just used whatever they had ..." :wink: ) and you win the Good Fortune prize. If as you say, the cap couples the output of the 12AX7 to the grid of the next stage, then polarity is irrelevant and, if you wish, you can use a .01 Mallory although a .02 might do a little better job of filtering out high frequency hash but good practice is to use 600V ratings in either case. John
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
Great! - Thanks John, I will report back when I'm done with the amp upgrade.

Cheer :D
Rog
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
Done with the upgrade... Yeahh! :D

Here is what I did:
- replaced all caps except for the .01MF 500V which looks to be in very good shape.( I have a 150 series replacement just in case.)
- installed an 35VA line isolation transformer(Triad: P-TN-51X) with a fuse block at the primary.
- installed a 3 prong power cord.
- The power cord ground "green wire" is attached to a terminal strip. From this same terminal a green wire is then fixed to the chassis.
- The transfo shield "white wire" is also attached to the same ground terminal.
- Checked all resistors...all ok.

Note: The 25MF was rated at 25V. The replacement 20MF is rated at 500V(much bigger in size but it fits neatly.)

I'm very happy with the sound. It sure make a nice little practise tube amp.

All in all i paid $125(amp) + $55(parts upgrade) + $20(vintage grill cloth - to do) for a total of $200.00

I guess it's not too bad. It gave me the opportunity to learn more about tube amp and to give the amp a second life. 8)

tubeampelectronicsmod64.jpg
 

capnjuan

Gone But Not Forgotten
Gone But Not Forgotten
Joined
Nov 29, 2006
Messages
12,952
Reaction score
4
Location
FL
Sharptone said:
It gave me the opportunity to learn more about tube amp and to give the amp a second life. 8)
Congratulations Rog; ya did good; you can't buy anything comparable for what you have in it and the rush from finishing a project (relief that it didn't blow up?) is hard to overstate. Will this be a one-off or are you keeping your soldering iron hot looking for another project ... maybe a DIY kit? Best, John
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
Will this be a one-off or are you keeping your soldering iron hot looking for another project ... maybe a DIY kit?
Right now, I have other projects on the go that I would really like to finish.
This tube amp project kind of bumped in, but it was worth all the efforts.
I think this could become a nice hobby.

Do you think that there is a market for refurbished old guitar tube amp?

This could bring in extra money once in a while.

Any way, thank you John for all the help.
 

capnjuan

Gone But Not Forgotten
Gone But Not Forgotten
Joined
Nov 29, 2006
Messages
12,952
Reaction score
4
Location
FL
Sharptone said:
... I think this could become a nice hobby. Do you think that there is a market for refurbished old guitar tube amp? This could bring in extra money once in a while ... thank you John for all the help.
Hi Rog; my pleasure to help .. but getting paid back for the time you spend on bringing back dumpster amps depends largely on the spread between what you paid for them and what you can sell them for. If your last name gains the imprimatur of Fender, Soldano, Fuchs, or Rivera, then maybe a 'Sharptone-refurbished', say, Gibson GA19 might move for good money on Cl or eBay.

Unless the fact that it was you who did the work, then even a good-running GA19 will only bring what the market will bear. This isn't the best example but here goes; back in the day when gas 350 and 454cid boat engines were more common, 2,000 hours - and goes for diesel too - was sort of a rule-of-thumb standard; gas engines needed to be replaced and diesels needed overhauled.

If you wanted to sell your $35,000 boat with 2,000 hours on the gas engines, you wouldn't get $35,000 for it. It would take nearly $10,000 to $20,000 to re-power with re-manufactured engines; re-built transmissions, clean out or replace the gas tanks, new gauges, exhaust, stainless steel motor mounts ... on and on and on; better part of $30,000 for new ones ... at which time you'd have $55,000 in your $35,000 boat. At that point, you are saying: "Hi; anybody want to pay $55,000 for my $35,000 boat with fresh power?"

No matter what these guys say, you don't do it for love or do it for money ... you only do it for love. As a hobbyist, the pleasure is making a broken thing work, or making it sound good ... and digging the tone ... if you get your money back on what you spent for the amp and the new parts, so much the better; this is fact, not a complaint! :wink: John
 

Sharptone

Junior Member
Joined
Apr 2, 2009
Messages
11
Reaction score
0
No matter what these guys say, you don't do it for love or do it for money ... you only do it for love. As a hobbyist, the pleasure is making a broken thing work, or making it sound good ... and digging the tone ... if you get your money back on what you spent for the amp and the new parts, so much the better; this is fact, not a complaint! John
This is so true. I think I will keep my soldering iron hot looking for other fun projects.

I guess, in the long run there is no use to hurry :wink:

BTW, nice video.

Rog
 

capnjuan

Gone But Not Forgotten
Gone But Not Forgotten
Joined
Nov 29, 2006
Messages
12,952
Reaction score
4
Location
FL
My pleasure Rog; best of luck at whatever you choose 8) John
 
Top