KT-5500 Mod w/ Black Gates,... will it perform?

[8xlaxx]

So, I finally got around to re-capping my Kenwood KT-5500 tuner using the information found here:

http://www.fmtunerinfo.com/DIY.html#KT-5500

I am awaiting a single 120uf 35V cap, as I forgot to order the correct quantity (hate when that happens!),... Therefore, I have not given a listen to this tuner yet.

In the above mod, 3.3uF 50V Black Gates were used in place of the .1uF 35V Kenwood stock blue tantalums. I am uncertain if the original modifier ('Jim') even used polarized or bipolarized tantalums. The Black Gates are now unobtainium. I ended up ordering the WIMA 3.3uF 50V bipolar caps to replace the stock .1uF 35V tantalums.

After scouring the interwebs, I was able to locate some new old stock 2.2uF 50V Black Gates that are polarized. In looking at the Kenwood KT-5500 PC board, there is a (+) and a (-) symbol stamped on it. I am curious if the 2.2uF 50V Black Gates (polarized version) would work in this unit as the polarity is clearly printed on the PCB?

Thoughts or help would be great! Thank you for reading my post.

EDIT: I wanted to add the BOM from Mouser that I used. Herein is the BOM:

Power Supply:
C49: 100 µF 16 volt changed to 120 µF 35 volt 667-EEU-FC1V121
C50: 220 µF 16 volt changed to 330 µF 35 volt 667-EEU-FC1V331
C51: 470 µF 16 volt changed to 560 µF 35 volt 667-EEU-FC1V561S
C52: 1000 µF 25 volt changed to 1500 µF 35 volt 667-EEU-FC1V152L
D6,7: W06B 150PIV, 0.75 Amp sub Schottky diodes 625-SB1H100-E3/73

Decoupling Capacitors:
C23: 100 µF 16 volt changed to 120 µF 35 volt 667-EEU-FC1V121
C53: 3.3 µF 25 volt changed to 4.7 µF 25 volt 647-UKL1E4R7KDDANA
C37: 100 µF 6.3 volt changed to 100 µF 10 volt 647-UKL1A101KEDANA
C15: 10 µF 25 volt changed to 22 µF 35 volt 647-UKL1V220KEDANA
C47, 48: 47 µF 10 volt changed to 47 µF 35 volt 647-UKL1V470MPDANA

Audio path:
C14: 4.7 µF 25 volt changed to a 10 µF 63 volt Nichicon Muse 647-UFG1J100MEM
C45, C46: .1 µF 35 volt tantalums changed to 3.3 µF 50 volt 505-MKS2B043301HJSSD

Others:
C6: .47uF50V 647-UKL1HR47KDDANA
C8,9: 1uF50V 647-USW1H010MDD
C11: 1uF50V 647-USW1H010MDD
C20: .47uF50V 647-UKL1HR47KDDANA
C21: .22uF50V 647-UKL1HR22KDDANA
C22: .33uF50V 647-UKL1HR33KDDANA
C29: 1uF50V 647-USW1H010MDD
C34,35: 2.2uF50V 647-UKL1H2R2MDDANA

@Spenser did a ton of the leg work on this BOM. I made one small correction to C23. Everything fits nicely and the values are spot on. Thank you again @Spenser.

I also included a 'possibility' for the Black Gates, but again these are polarized NOT bipolarized caps like the WIMA:

DRAFT DRAFT DRAFT

C45 and C46: .1uF 35V tantalums changed to Nichicon 50volts 3.3uF 85c 5x11 2LS 647-UFG1H3R3MDM

 

[Spenser]

This is great, 8xlaxx.

Watching with interest. Thanks for the kind words.

I made one small correction to C23.

The reason I had selected 647-UKL1E101KPDANA, for C23, which represented a bump in voltage only, to 25V ...uh...let me think here...departed from Jim's recommended changes of impedence and voltage (he said to increase to 120 uF 35V)... I think I was unsuccessful in finding the desired impedence and voltage of the Nichicon KL on Mouser, yet wanted to stay consistent in make and model on all the decoupling capacitors. Something like that.

Looking forward to hearing what others think and your ultimage outcome.

I have two of these tuners myself. Was thinking about doing restore / mods to at least one of them.

 

[8xlaxx]

@Spenser

Sorry about that, my mistake,... I meant C37.

You have/had:
C37: 100 µF 6.3 volt changed to 100 µF 10 volt 647-UKL1A101KEDANA
...listed, where Jim had a 100uF 25V listed. No biggie, just a voltage jump as well.
Again my apologies.

Keep at least one of those tuners!

 

[hopjohn]

Firstly, don't waste your time or money with any of the Black Gate capacitors (and if you got them from ebay good chance they are fake). They were good for their day, but have been out of production for10 years or so. Kinda silly to recap something with electrolytic caps that have been sitting around that long when the whole point is to get rid of old capacitors. For signal path audio caps around 10uf and above I like the Elna Silmic II, Nichicon KZ and Nichicon FG series caps which you can get new from mouser.

The FM tuner guys have gone through those mods and tweaked them to their liking so any questions you have about cap changes or values should probably be addressed to them.

If it were me I'd be using a film cap (probably a wima or kemet polyester film ) in place of any 2.2uf electrolytics. I try to use film up to 4.7uf where they fit.

 

[8xlaxx]

@hopjohn
Thank you for the reply.
I finally got the order from Mouser and finished the recap on this tuner,...I had forgotten to get an extra 120uF 35V cap, duh.

I think the audio path sounds great with the WIMA 3.3uF 50V film caps installed. I hear more low end which is quite pleasing to the ears, not fatiguing. For now, I nixed the idea of slapping in the BGs. It just didn't make sense to purchase those caps at a price or $15/ea. Yes, they were the real deal and the seller was legit, but all sales were final and the value was a little larger than the .1uF tantalums, but less than what 'Jim' had established in his modification. I look at the WIMAs as a decent option. My poor ears probably couldn't tell the difference between the WIMAs and the BGs anyway.

Tuner is 1-2 kcs off but playable and listenable. I 'might' try and alignment,... will see.

 

[hopjohn]

Happy to hear it all worked out for you. I haven't modded the KT-5500 but have the 7500. They go to the extremes over at the FM site with some of the mods. In theory the film caps should sound better.

Cheers

 

[swamppirate]

@8xlaxx Good to see you cranking on some tuna recapping action dude! You have inspired me.... I may give my
KT-7500 a go!

 

[8xlaxx]

@swamppirate

Hey brother!
Yes, recapped it last week. Sonics are great and there is no listener fatigue. Caps were purchased from Mouser and the BOM is on another thread here. My recommendation is to do the recap and have fun performing it. The payoff is worthy.

 

[8xlaxx]

Wanted to give a quick update on the tuner.

I ended up going with the WIMA film caps in the audio section on this unit. The FM stereo LED was fickle prior to and following the re-cap until I re-adjusted VR-2 on the board. After a quick tweak to that VR the tuner came alive and is completely functional in every way. Too bad this tuner feels like a little toy because it sounds really good now. The FM Stereo red LED is now opening up with no muting issues any more and no longer flickering but solid on the strongest stations. Super sensitive, too. The tuning and strength meters re-aligned themselves which is very interesting. I swapped out a shorter antenna and made a 30" wire using the 750ohm screw down lug. Made a big difference, IMHO.

I unscrewed the white string dial and re-adjusted the dial to get it smack on frequency. This unit is worthy now! Thanks again for the help! The above BOM is good.

 

[swamppirate]

The KT-7500 is back in the lineup... Had not listened to it in a while....

 

[8xlaxx]

These are very listenable tuners. Glad I recapped mine.

 

[Spenser]

Hey 8xlaxx. Hope this finds you well. I've got my KT-5500s on my bench. I cannot find service manual or schematic. Can you help? Cannot remember ever having either. That's not saying much because I cannot remember diddly! I'm having the 'FM indicator issue' on one of them. Which is the VR2? I'm frightened of throwing off the alignment. Thanks.

 

[hopjohn]

No need to buy new meters. The KT-5500 uses one lamp for both meters. The photo I had showed at least one lamp on the right side, but there is probably a second on the left for the dial illumination so I'd purchase three lamps to be safe. All original lamps would be 8V 250mA or 300mA. The originals will be soldered in unless it's been modified so expect to do the same to replace them. There are a number of different lamp options you can purchase to do the job. You can contact AKer dgwojo at his site for help or you can go it alone and use #51 bulbs or wedge based 8V 250ma/300ma bulbs from eBay, Amazon and other sources.

Edit : I verified that there are indeed 3 lamps in a KT-5500. 1 for the meters, 2 for the dial.

 

[Mike Sweeney]

I replaced mine with LED replacements. Tricky to solder in but work nicely.