Vintage Audio Review Episode #21: Kenwood KA-7100 Integrated Amplifier
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- Опубліковано 21 лип 2024
- I this episode I talk about a Kenwood KA-7100 Integrated Amplifier that was brought to me to be repaired.
00:00 Introduction/ Description of KA-7100
01:38 Front Panel “Tour”
03:45 Rear Panel “Tour”
05:02 Top Inside Cover Off View
06:02 Problem with Unit
07:20 Measurement Data
15:06 Final Thoughts
I know that this is a old post but I just wanted to say that after watching this video it gave me the confidence to investigate a similar issue, after taking the amp cover off I found all electrical and mechanical components completely covered in dust, clean with compressed air and lubricated all mechanical switches with electronic approved cleaner and lubricant, turned power on and it sounded fantastic, the musical nuances that comes through this amp have to be heard to believe. Thanks for sharing!
Glad to hear that the video was an inspiration to you and you were able to get the Kenwood working well!
Thanks, another nice choice to review. It is still a good piece. Like the other comments, this Kenwood was the core of my 2nd system from back in the day. 🔈🔉🔊
Thanks once again. Kenwood gear gets a lot of love, though not on some other channels so much. I basically get things to look at from some of my friends here in town, so it is really a luck of the draw.
I have always loved my Kenwood amps and still use one in the shop!!! Well done Scott.....
Thanks Mike! I have liked the two Kenwood integrated amps and one Kenwood receiver I have reviewed. You certainly can fill your workshop/garage up with some pretty good tunes with your system!
My first real receiver was a Kenwood KR-2400 back in the early 70's. It very nice sounding and good looking also. I sold it for a Kenwood rack system after about 10 years of use. About a year ago when I decided to pull out the several pieces of vintage gear that I had held on to. I purchased a mint condition KR-5600 off of ebay to be the centerpiece of my new/old setup. I struck gold and I am enjoying that warm Kenwood sound again through my Bose 501s! :-)
Got mine in 1978 still listening to mine and still love it
Glad it is still going strong for you and that you kept it!
I have it hooked up to my original DlK 1 1/2 's with some realistic super tweeters I got at Radio Shack . My tuner is a
KT 5500 . A TEAC Casette deck along with a AkIA reel to reel. When I was 20 I was in a painters Union and was living at home.
@@mikepatania1375 Sounds like a pretty cool "vintage" system. I will have to check out the Radio Shack super tweeters- I have a faint memory of them...
@@vintageaudioreview Sometimes you can still find them on eBay. The best ones are from Japan Not Korea. Made in Japan a lot heavier than the ones from Korea. I have enjoyed our conversation
@@mikepatania1375 As Have I! That is what makes having this channel more fun for me!
Looking at my unit… center of attention for considerable AV setup… always works and always enjoy the audio quality across many platforms.
This is certainly a crowd favorite- glad it is still cranking out the tunes for you.
These are exceptional units. I would stake it up against a Marantz 2270. If you can find them, buy it. The price is going up on these. In 2023 a fair price would probably be $800 to $1,200 for one in pristine condition. In 2023, that's not a lot of money folks.
While it has been a while since I listened to either of them, I think the 2270 would be my choice. Both are popular and seem to be getting pricier. There is definitely a Marantz tax. Thanks for commenting!
Great review…still have mine that I bought in the late 70s. Just brought it out of storage.
If it worked before you put it in, it most likely will work fine- good look!
I recapped mine with Nichicon capacitors, it sounds so beautiful, so natural, excellent amplifier. It does not get as hot as AC integrated circuits.
Thanks for the comment! People really like Kenwood gear, and for good reason.
Filter or power caps? Was it hard to do?
@@ShazeemKhan caps, 37 if I recall. Not hard, just replace one at a time to avoid confusion.
@gp8033 wow 37 caps?
Interesting ok thanks so much for the information my friend. Good advice on replacement too. I got mine on Sunday, love it! I named it Mr Rogers lol
@@gp8033 btw where sells them?
My first "silver face" from the Golden Age. Love mine.
The designer of this Kenwood 7100 Amplifier established Kenwood's sub-industry, ""Accuphase"", after this model
That is a fact that I did not know.....
Just bought one for $40 plus $70 shipping 😬 power switch was bent straight down when it arrived but managed to straighten it out with some pliers , works good , definitely needs deoxit on everything but for some reason I can’t hear a difference with loudness on on either setting or off
Pretty good buy! I think you need to have the Tone Defeat OFF for the loudness to come into play. The loudness will boast the bass only, by 3-6dB depending on the frequency and switch position.
@@vintageaudioreview first time I played it no sound came out until I turned on tone defeat , I also have to keep the knob between tuner and aux for my Bluetooth aux to work , I’ll try to see if having defeat off will make loudness work
@@chickenfoundation9323 I'm not sure how easy the input selector switch is to clean/lube with Deoxit, but I would try that as well as making sure that the selector knob is in the correct spot for the selection if that makes sense.
@@vintageaudioreview yea all the knobs are in the correct spot
@@chickenfoundation9323 By correct spot I mean when the selector switch is say in Aux "detented position", are the switch contacts lining up correctly as it looks like the switch shaft has some set screws on it to where it could be adjusted- I am assuming that other inputs work without finding a "sweet spot"...?
Could diagnose what causes all of a sudden my Kenwood ka 7100 no output and no relay click, Thanks in advance.
Most likely a blown output transistor(s)....
Could you do a similar analysis to the LUXMAN L505uX MARK II?
Thanks for asking but I am at the whim of a couple of my friends as to what gear they have and the Luxman is not among them at this time.
And do you have any opinions on that integrated amplifier?
@@gadgets72 If you are talking about the Luxman, I don't have any experience with it so it would be a guess, but they make good gear.
I own that, went thru hell getting that giant volume knob to function properly.
I am glad you got it to work properly- was it a problem with the detent mechanism? How do you like it?
@@vintageaudioreview Had to turn it upside down, and literally flood it w/ lubricant and ran it upside for a few hours occasionally turning the knob every 10-15 minutes. Power toggle switch had a slight bend, so got it pretty cheap on EBAY. I think it was $190 + ship. Like it very much, wish it had VU Meters like my other integrated Amps. 1976-1981 is what I like.
@@robertdavis5714 sounds like your efforts paid off! There are a lot of great pieces of audio gear over the '76-81 range. Speaking of meters, I think my next video is going to be on a power meter..
@@vintageaudioreview Yes, something about those big volume knobs om Kenwoods, 5700 same thing but Hummmmmmmmm noise, where all my Pioneers never an issue. Have 5 systems in house with 19 pairs of speakers + 1 sub, and probable another 4 sit in closet and then I rotate when I want to see something different.
@@robertdavis5714 You would make a great interview for me! In my "man cave" room I have 11 speakers & 2 subs and 4 "systems".
Saw one of these today at the goodwill for $159.00
If it was in good physical condition, I hope you purchased it....
The transformer has one transformer but two windings. That is how the they worked out the dual power supplies with one transformer.
Thanks for the clarification! I did not spend a lot of time looking at the schematic (or the transformer) to verify the "claim" in a written review that there was a power supply for each channel.
@@vintageaudioreview the previous model had two transformers but it also had the chip based amplifier modules (can't remember the name right now) that when they malfunction are near impossible to fix or find replacements. The 7100, from what I have read, was an attempt to reduce cost but keep performance as close to the previous model as possible. I just wish they kept the pre out/amp in of the previous model. I assume that was cost cutting as well. The heat sinks on the previous model were much more substantial as well. I sometimes wonder if that is why the 7100 can get a little harsh in the upper mids when pushed.
@@jked7463 I would agree with not having the pre out/main in jacks was probably a cost savings idea, though I would imagine a lot of folks never use it that way. The engineer in me tells me that not having larger heatsinks would not affect the sound much if at all- more of a reliability thing than anything else, though a hotter running output transistor or FET is going to have a different amount of distortion than a cooler running one, though I don't know if that difference would be audible,,,,
@@vintageaudioreview My point is that if the heat sink were larger, the transistors would run cooler when pushed hard. I believe I can hear distortion as I push it hard. To me the difference in distortion as it gets louder, is more audible than a base level of distortion. If you start at 0.5% and go to 0.6% it will be less noticable than 0.003% to 0.6%. We love to talk in absolute terms in audio. I believe relative differences count more than absolute.
@@vintageaudioreview I agree most people won't use them. But I am planning on installing some on my for a bi-amp speaker arrangement. A separate amp for the bass, below 250 hz and the 7100 for above 250. I believe it will stress the output transistors less and lower the distortion discussed in a previous post.
The phono stage is known to be very good. There is something wrong with the phono stage. The only problem that I have experienced is that that it doesn't have a lot of headroom and can be over loaded with a cartridge with high output.
I would agree that the right channel on the phono stage has a bit of a problem. None of the folks whose gear I have worked on care at all about having the phono stage working (so far)- they could always hook up the phono preamp of their choice to an Aux input is what they tell me. I typically just like to show how it has aged with time. I typically only measure the phono stage with a 5mV input unless the spec specified something else. Sometimes there may be an overload spec for the phono stage, but I am not sure that I have tested that more than maybe once. Thanks again for taking the time to comment!
@@vintageaudioreview I have a ortofon 2m black and it can definitely overload the preamp. It has been replaced by a ps audio phono preamp which is better/more refined and can handle the high level of the cartridge.
Ищу КУЕНВОД-7100 именно Кенвод а не Трио.
The designer of this Kenwood 7100 Amplifier established Kenwood's sub-industry, Accuphase, after this model
I did not know that- thanks for the input!
@@vintageaudioreview Thank You Mister...You are a good Man 😊😊
@@monsterleather9621 Thanks Kindly!