Tuner Modifications

Reginald

New Member
Greetings: I have read a few posts that mention modifications or upgrades to tuners that greatly increase their performance. One name mentioned is Bill Ammons who apparently has experience doing this. What exactly are the changes involved? I have a KT-8300 that to me sounds quite fine. Would I notice a large improvement after getting this work done?

Cheers
R
 
If your reception is already clean and quiet, I doubt you will notice a difference. If you have problems picking up weak stations or if the weak stations get interference from nearby stronger ones, modifications will help. Otherwise all you can do is re-cap and replace opamps with better ones, which will improve the sound, IF you have crummy opamps in the first place. Go to:
http://www.fmtunerinfo.com/
and see what they recommend for the KT-8300.
 
Hi

Mods generally fall into 3 areas:

IF amplifier mods. This is where the exisiting IF ceramic filter modules are either replaced with ones with a narrower or wider bandwidth to suit the prefence of the user, narrow for better DX performance or wider for lower distortion. Sometimes the filter bandwidths are kept the same but matched to better center them in the bandpass. Kind of like 'blueprinting' an engine.

Capacitor upgrades. This usually involves replacement of all audio signal path capacitors with better performing caps. The power supply filter caps are also often upgraded.

Audio Op amp upgrades. This is to replace older op amps with newer, lower noise Op amp devices.

The most frequent done performace improvement is to have the tuner completely aligned and adjusted for best performance. This requires both special test equipment and of course experiance in FM tuner alignments. A good alignment is worth is expense, but it's besst to use someone that comes recommended rather then taking a crap shot with some local tech that you have no history with.

I would recommend that first a good alignment be done before any extensive modifications are tried. You might find that the performance improvement is more then enough before going down the mod path.

Lefty
 
Lefty said:
Hi

[...]
I would recommend that first a good alignment be done before any extensive modifications are tried. You might find that the performance improvement is more then enough before going down the mod path.

Lefty

Ignorant question: If you do the alignment, then do the mods, is the alignment affected by the mods?

Bob
 
one caveat to Lefty's post- if you do nothing else modwise; recap. You will hear the difference in the imaging and detail. 8300's are 25+ years old now and due for recapping anyhow- then align it and you'll be good for another 20+ years!!!
 
Reginald,

If you decide to go the mod route I'd be interested in reading about the results. The KT-8300 is a very nice tuner as is.

I'd like to see what difference an alignment makes. Anyone in the DFW area who can align my KT-8300?
 
Hilltroll67 said:
Ignorant question: If you do the alignment, then do the mods, is the alignment affected by the mods?

Bob

Yes the alignment will be affected by new caps some what. Definately with new filters.

When I rebuild a tuner I usally let it burn-in at least 60 hours before doing the alignment.

There's a fully mod'ed 8300 in the classified section. Might be worth checking into.

The 8300 will definately benifit from newer matched filters. At the very least recapping the power supply. New quality audio coupling caps. There are 4 opamps. 2 are used for metering and muting and not critical. The output opamp should be upgraded to a quality audio opamp. The first opamp on the MPX board you should use a mixed signal opamp. I've seen some oscillation issues with using a burr-brown in this posistion.

X
 
Thanks for the info. You people really know your stuff. I am sure that the capacitors could benefit from replacement but like I said (maybe it's my old ears) I find the tuner to be quite fine in its current state. I am from Canada and there is not the same amount of "dial crowding" that I'm sure there is in the U.S. so station selection rarely has another station close by. Does anyone have an estimate on what each of these upgrades cost? Re-capping, Op-amp etc.

Cheers
R.W.T.
 
Perhaps being a little too pedantic here, but I would classify recapping as a "repair" as opposed to a "modification".

You aren't necessarily changing the specs or circuit, just replacing old, worn-out caps with new ones.
 
I guess it depends where the caps are and if "upgraded" caps are being installed in place of the existing ones I guess. I have a "modified" Mitsubishi DA-F20 that should be on a UPS truck coming my way from Punker right now with Blackgates in the audio path which I hope constitute a modification to the better. :D
 
VPIVinylspinner said:
I guess it depends where the caps are and if "upgraded" caps are being installed in place of the existing ones I guess. I have a "modified" Mitsubishi DA-F20 that should be on a UPS truck coming my way from Punker right now with Blackgates in the audio path which I hope constitute a modification to the better. :D
Based on my experience with three tuners Punker's done for me (so far)...you're in for a really nice sounding surprise! Just give those BlackGates at least 100 hours (even more is better) before you listen seriously.

Dave
 
A tuner with audiophile mods like my Kenwood KT 7500 sounds far better than the stock one. I had both at the same time to compare. It's very audible and nice. You can have a world class tuner. I'd recommend Mike Williams of Radio X tuners who's one of the sponsors of this forum, he's very reasonable and competent. You can't just have any tech mod an older analog tuner btw. In the end your modded KT 8300 would sound about as good as any tuner made including cost no object tuners that cost thousands.
 
"I would classify recapping as a "repair" as opposed to a "modification""

I'd call it an overhaul. Maybe the existing caps are still working well enough, but an overhaul will use components that can be better than the originals but are still conform to the same original design concepts.
 
gearhead said:
What about cost? What would it cost to modify a KT-8300?
Radio X Tuners is a site sponsor for AK. Visit there and ask Mike about all of the upgrade options, from sane to all-out, and see the range of costs. He doesn't detail every last upgrade on the website, so you should ask. Then you can decide just how good you want your KT-8300 to get!

Dave
 
i would *STRONGLY* recommend getting this tuna refurbed *and* upgraded. i owned a stock unit, & it was, along w/a refurb'd mcintosh mr77, the only tuna i wouldnt' wanna listen to long term. or even, short-term, for that matter. ;)

tho it was quiet, sensitive, & had good frequency response, its soundstaging was not the widest, & it was extremely two-dimensional - no depth at all. i have owned literally dozens of tunas over the past several years, & frankly, this one yust doesn't cut it, if you have a station that delivers a quality uncompressed signal & a rig revealing enuff to show it.

modded, on the other hand, the story is completely different. i owned a modded kt7550 (a bit below the kt8300 in the kenwood food chain), & its sound was *fantastic*. so, it's definitely worth getting refurb'd & modded if you like its looks & ergo's.

ymmv,

doug s.
 
Well, Punker is a mod on this forum, he should be reading all this and chime in, heh heh.
He's done stuff for me before.
My Marantz 4430 receiver he tooned up works well, I have it hooked up to a roof mounted Radio Shack antenna.
 
It Shall be done...

Here is a cut/paste from another thread I responded to. I figured it should be here as well.

"What originally started out as curiosity has now developed into a "must try". The tuner is now 27 years old and really could do with the upgrades. Once I'm done paying my savings account back for the KEF's it is headed out for the complete rework. I really am looking forward to hearing how it sounds.

Cheers
R
 
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