Tivoli Radio Hiss (Amplifier gain issue?)

[tool1075]

I really enjoy this forum, and I thought I would finally register so I could ask you guys a question

I own a couple of Tivoli table radios. I own a Model Two (stereo) and I just bought a Model One (mono).

The Model One is the radio I have the problem with. I am getting an audible hissing noise from the speaker. It really sucks, because if you play music quietly, it gets very annoying, and sounds like the station isn't coming in correctly.

Here's what I have done to diagnose the problem:

1. Turned the volume all the way down. (Hiss still there).
2. Changed the input selector. (Hiss occurs on FM, AM, or AUX).
3. Used a DC power supply instead of the included AC cord. (reduced some Hum, but there is still Hiss).
4. Tried different power outlets, in different rooms, in different buildings, with and without surge protectors. (Hiss still there).
5. Used headphones. (Hiss GONE! There is no hiss when using headphones)

6. Returned radio to Tivoli, and received another radio DIRECT from Tivoli (THE NEW ONE STILL HAS FREAKING HISS).

7. My Model Two does NOT have hiss.

So, from the above, would you guys agree that the speaker amplifier in the radio has its gain set too high? (coming from the car stereo world, that's what it sounds like to my ears- like there is system noise being amplified).

I have emailed Tivoli, again, but they haven't responded yet. Maybe they will shed some light, but I don't want to return yet another product if all of them are like this.

Anyone have any insight? I would really appreciate the help!

 

[Dan ʕ•ᴥ•ʔ]

As far as I know, the headphone out is NOT run off the power amp section, which is equalized for the internal speaker. I have an early version of the Model One, but it's dead quiet as far as noise goes. I'd say the power amp in yours definately has problems. Did you check serial numbers to make sure that Tivoli sent you a new unit? Strange that two of them in a row would be defective. Anyway, stay after them and like another thread here earlier today...a phone call to the C/S Dept. probably would be a good thing in getting it resolved.

 

[tool1075]

Thank you for your reply.

Yeah, I agree about the headphone output not being run off of the speaker amp, and that explains why there is no hiss when listening through headphones.

When I called customer service the first time (to get an RMA for the first radio, to return it) the guy I spoke with said that they are changing something with the manufacturing. I don't know if that means the method, location, parts, or whatever.

Having heard that, I was hoping that the new radio I received would be new enough to not have that problem (or old enough, who knows).

The serial number of the old radio had an "0806" in it, which I thought meant that it was manufactured in August, 2006.

The serial number of the NEW radio has a "0807" in it, which maybe means it was manufactured in August, 2007? Who knows. Maybe Tivoli will respond to the email. I'll call them again, if not.

Oh, I almost forgot:

Interesting to note is that I'm not the only one with this problem. (with two radios, no less). Check out the following reviews on Amazon.com-

All of them mention a problem like mine:

http://www.amazon.com/review/R3JMYZBT6VAYCC/ref=cm_cr_rdp_perm (dated August 16th, 2007)

http://www.amazon.com/review/RAD14RXOMCHEQ/ref=cm_cr_rdp_perm (dated June 8th, 2007)

http://www.amazon.com/review/R26IGCEBNG9YIU/ref=cm_cr_rdp_perm (dated March 14th, 2007)

http://www.amazon.com/review/R3IG2Z8G9QZ6GH/ref=cm_cr_rdp_perm (dated August 25th, 2007)

Look at the dates. Coincidence? Maybe. Am I just having bad luck here? Man, I hope so, cause I really like this radio! I just wish it didn't hiss at me.

 

[Dan ʕ•ᴥ•ʔ]

Wow! That is such a shame. The internals of my radio are well made. The amp, tuner and pre-amp are all on seperate boards and the vernier tuning reduction is done by brass gears and it has a Fostex speaker. But that said, I bought mine the first year they came out (#06908) and the walnut is much richer in appearance than the newer ones.

 

[tool1075]

yes, I agree.

I'm hoping that whoever manufactures the radios (somewhere in China, probably) just messed up, and the original design is okay.

Out of curiosity, you've opened your radio? I don't want to open mine, because I don't want to void the warranty (yet).

Tell me... is the gain on the speaker amplifier adjustable? Not only is there hiss, when you turn the volume up, it gets loud too fast. Know what I mean? Definitely seems like the gain is too high...

I wonder if there is a variable resistor or some kind of potentiometer in there to adjust?

 

[Steve O]

I have a Tivoli Model 1 serial #90573, mfg date 10-01. Actually, FWIW, it's called the Henry Kloss Model 1. There is a faint hiss and hum with my ear against the speaker but it's not audible when more than 6" away from it. Also, the internal construction is...well...ah...cheap. Among other things, a rubber band is used to hold the AM loop antenna in place. I also had a problem with a "chuffing" noise eminating from the jacks on the back panel when bass notes occur. I ended up taping them over to eliminate it.

Overall, it's an OK, pleasant sounding radio but not up to the hype you see everywhere about it. The KLH model 8 (which is sorta what the Model 1 is patterned after) blows it away in every possible category except AM reception.

 

[tool1075]

Yes, I'm aware of the radio's lineage. I have also read about the rubber-bands used in its construction.

I like my Model Two, so I got a Model One to use on my desk in my office at work. I became aware of the hissing noise, because I listen to music at low volumes at work, and the hissing noise is very noticeable.

Like I said in my first post, my Model Two doesn't have this problem like the Model One.

Anyone know if the speaker amplifier gain is user-adjustable?

Thanks again.

 

[Dan ʕ•ᴥ•ʔ]

As far as I know, on MY radio, the gain is not adjustable. Maybe trying other pots with different resistance will help. Yeah, been in mine before. There are pics of it somewhere. The AM and FM antennas *were* held in place with rubber bands (nylon ties now) and the port does chuff on certain frequencies. But I'd rather have it than a plastic FONY radio.

 

[philcib]

Anyone know if the speaker amplifier gain is user-adjustable?

I suspect that a change of resistor value in the feedback loop or at specified
gain set pins of the amplifier IC is what you have to do. Do Tivoli even give
out schematics to end users?

 

[tool1075]

Nope, they don't give out schematics, service manuals, or anything.... it's a real bummer.


However, I did get an email back from Tivoli today. They will be "personally" testing another radio to send out to me, and are sending me a return shipping label for the second defective one, so that's pretty cool.

We shall see. I'm out of town on business at the moment, so I'll let you guys know what happens.

Thanks again for the help.

 

[tool1075]

Well, I won't be buying any more products from Tivoli Audio, and you can count on that.

I received the SECOND radio from them- and it has the same damn problem. I emailed them, yet again, asking for a refund- and they haven't written back.

So, I just called them.

Basically, I was told that the problem was not a known issue, and that there is probably nothing wrong with the radio. They will be testing the 1st one I sent back soon, and they will "get back to me."

So, when they "personally tested" the one I just received from them, they must not have done it in a quiet room, because if you can't hear that hiss- you're deaf.

Stupid Tivoli. Henry Kloss is probably rolling in his grave.

 

[tool1075]

Just went to Target and bought a Boston Acoustics "Horizon Solo."

Better sound, build quality, features, and reception, than the Tivoli. I would recommend it to anyone looking for an alarm clock and/or table radio. $99.99 at Target, so I assume it would be easily purchased for most people.

 

[NickDanger55]

That's a strange problem, for sure.

I've been using a Model One since last November. I tried it at home and it worked great. Pulled in stations clear as a bell. No hiss or other noise to my ears. I took it to work to use on my desk. It worked the same there as in my home. In fact, several of my co-workers liked the tuning capabilities and the clear sound, they bought one for themselves!

I wonder if there is something else causing the noise you hear? Interference from an outside source maybe?

 

[tool1075]

Nope, no outside interference. Tried AC power, DC power, different outlets, different surge protectors, different rooms, different buildings.

With the volume all the way down, any radio has an audible hiss when you touch your ear to the speaker, but you shouldn't be able to hear the hiss when you are sitting feet away from it.

 

[tool1075]

lol well Tivoli called me to tell me they received the last radio I sent back to them (the previous conversation on the phone with them was concerning the previous radio I sent back - yes this has been going on a while)

The lady on the phone said that it is "completely normal" and the reason other radios (by other manufacturers, and "cheaper" radios") don't have that problem, is because the Tivoli radio is "more powerful." lol

what? lol

I asked why my Model Two DOESN'T have this problem. She said "We tested those too, and they sound the same as the Model One." Then I said "Well, I guess I just got lucky with mine..."

She said that all of their radios do that, and the reason for any other manufacturer's radio NOT having the problem (besides Tivoli's being more powerful :screwy: ) is because they use "different circuitry." lol I hate her.

I then asked her if she understood what "gain" was. She didn't. So, I asked her if I could speak to an engineer, or a technical person about adjusting the gain. She still didn't understand. Then she said that wasn't allowed.

I said- "I don't care about the warranty- I just want to make it sound good. If I break it, who cares?"

And then she said "It's not about warranty- it's about patents. We don't release any information about our radios."

AAAAAAnd we've come full circle.

I'm sitting in my office right now, listening to the local classical station on my brand-spanking-new Boston Acoustics Horizon Solo from Target.... less than a $100 and it gets way better reception than the Tivoli, has better sound quality (in my opinion, due to the port being on the back instead of the bottom) and waaaay more features.

I liked the analog tuner and signal strength indicator of the Tivoli, as well as the wood cabinet. Oh well. Maybe some other company that doesn't SUCK will make one like it! Oh, wait, I forgot- patents!

Bastards.

 

[Urizen]

I love my Tivoli.

RIP, Mr. Kloss.

 

[tool1075]

I love my Tivoli.

RIP, Mr. Kloss.

lol I love my Model Two! If you have a Model One, you must have gotten one a while back. Such is life.

Oh, yeah, by the way, remember how I was saying that something with their manufacturing process changed? The only thing that changed (supposedly, according to one of the Tivoli reps on the phone) is that they no longer use lead-based parts.

Yummy.

 

[www.records]

I walked in to my local GW this afternoon and sitting on the shelf was a brand new Tivoli One, still sealed in the box. They had it marked $30 and it sounds great for what it is. I listen to a lot of sports radio and looking forward to MLB season. I prefer to listen on the radio over watching the game on TV. Weird huh? I think this little radio will work nicely. No hum found.

 

[tool1075]

I walked in to my local GW this afternoon and sitting on the shelf was a brand new Tivoli One, still sealed in the box. They had it marked $30 and it sounds great for what it is. I listen to a lot of sports radio and looking forward to MLB season. I prefer to listen on the radio over watching the game on TV. Weird huh? I think this little radio will work nicely. No hum found.

No complaints about hum, just high noise-floor. Turn the volume all the way down and listen. If you can't hear a hiss, you got an early model, or you're not in a quiet place.

 

[www.records]

No complaints about hum, just high noise-floor. Turn the volume all the way down and listen. If you can't hear a hiss, you got an early model, or you're not in a quiet place.

I must have gotten an early model, because no hum or hiss. It is Cherry/Cobalt faceplate, early model?