Popping with preamp and amp.

[vr6ofpain]

The amplifier used is an Adcom GFA-545. The preamp used is a Harman/Kardon PT2300, both units are older (Adcom from the 80's, H/K from early 90's I believe).

With this preamp, which I just picked up, it pops when I switch between sources. It also has a Pre-Out control to select Off, A, B, or A+B (it has two preamp outputs). If I toggle between these controls it also pops.

Now I am used to the pop of the old Adcom when I switch on its power (so I leave it on all the time), but with the Lexicon CP-3 I was using as a preamp, the pop upon turn on/off was very minimal and there was no audiable sound between source switching.

Does something cause these noises (oxidation of internal components, capacitors failing, or something of the like), or is it just the vintage of these electronics?

Thanks for any input.

I just get annoyed that these 'nicer' components do this, but these cheap Kenwood receiver I have from the mid 90's does nothing of the sort and it was $250 in the mid 90's.....being cheap and made in China (back when that still meant it was crap).

[JoeE SP9]

The amplifier used is an Adcom GFA-545. The preamp used is a Harman/Kardon PT2300, both units are older (Adcom from the 80's, H/K from early 90's I believe).

With this preamp, which I just picked up, it pops when I switch between sources. It also has a Pre-Out control to select Off, A, B, or A+B (it has two preamp outputs). If I toggle between these controls it also pops.

Now I am used to the pop of the old Adcom when I switch on its power (so I leave it on all the time), but with the Lexicon CP-3 I was using as a preamp, the pop upon turn on/off was very minimal and there was no audiable sound between source switching.

Does something cause these noises (oxidation of internal components, capacitors failing, or something of the like), or is it just the vintage of these electronics?

Thanks for any input.

I just get annoyed that these 'nicer' components do this, but these cheap Kenwood receiver I have from the mid 90's does nothing of the sort and it was $250 in the mid 90's.....being cheap and made in China (back when that still meant it was crap).
If you preamp uses mechanical switches it could be no more than dirty switch contacts.If so, try spraying contact cleaner on the offending switch and vigorously working the switch. This is best done with the unit disconnected from the AC.

[vr6ofpain]

If you preamp uses mechanical switches it could be no more than dirty switch contacts.If so, try spraying contact cleaner on the offending switch and vigorously working the switch. This is best done with the unit disconnected from the AC.

Well I will try this on the Preamp output switch, because it is a rotary mechanical switch. Strange thing is, none of the other rotary switches (volume, balance, bass, treble, sub level) make any noise when they are rotated.

The input switching is not mechanical, but buttons that are 'soft' or 'digital' in the sense that I can change them with the remote. But when I switch from one to the next it pops. strange thing if i switch from any input to either of the tape inputs there is no pop.

Switching from the tape inputs to any other input, or from the other inputs, it always pops, even when switching to the tuner, which is built in.

Frustrating. I'm almost thinking of going back to the CP-3, and continuing to try to locate a remote for it, or possibly buying a newer preamp.

You have also have a GFA-545. Yours pops(in the speakers) when you physically switch it on or off correct?

[JoeE SP9]

I never turn any of my solid state gear off. Of course, I do power down the tube stuff but the transistorized stuff is always on. When I get the Krell power amps I'm saving for I will probably power them down when they are not in use. Class A amps suck lots of watts from the wall. Two KSA-100's will increase my electric bill by a substantial amount.

[old_s13]

I would suspect its the HK unit.

I'm done with HK, I dont like their products much.. especially their newer line of goods, very very cheaply made. If anything, I like Infinity's older speakers though.. their Kappa line has always been pretty good perfomers.. I'm a big fan of EMIT speakers.

Anyway, pre-amps are cheap nowadays.. why not pickup a used pre-amp off e-bay? I've had nothing but good luck with Marantz products. In addition, I opened up various Marantz components and not only are they easy to work on, but very easy to service as well.

Good luck!

[vr6ofpain]

I would suspect its the HK unit.

I'm done with HK, I dont like their products much.. especially their newer line of goods, very very cheaply made. If anything, I like Infinity's older speakers though.. their Kappa line has always been pretty good perfomers.. I'm a big fan of EMIT speakers.

Anyway, pre-amps are cheap nowadays.. why not pickup a used pre-amp off e-bay? I've had nothing but good luck with Marantz products. In addition, I opened up various Marantz components and not only are they easy to work on, but very easy to service as well.

Good luck!
I DID PICK THIS UP USED OFF EBAY. It is from the early 90's I believe, definately mid 90's or earlier. It is also made in Japan, which for Harman/Kardon shows that it is older.

Also more to the point, you are talking about powering on/off. My main concern is the popping when changing between sources, because that is something I would do often.

[vr6ofpain]

http://i7.ebayimg.com/02/i/03/d9/dc/b6_1_b.JPG
I picked it up for $89 shipped with the remote and manual.

[old_s13]

Also more to the point, you are talking about powering on/off. My main concern is the popping when changing between sources, because that is something I would do often.

i never said anything about powering on/off...

i just said that HK is the suckiness. :-)




btw, have you even tried opening it up and giving it a good cleaning? if you break it, atleast you can go buy a good pre-amp. hehe but in the meantime, maybe you can fix it.. you have nothing to lose.

[vr6ofpain]

Yes you're right, it was JoeE SP9 who said that.

[vr6ofpain]

I switched back to the CP-3. I was right, it does sound much better. Not nearly as bright, and for some reason it seems more full. The H/K sounds "tinny". I think I will either put it up for sale on ebay....or possibly keep it for the tuner and phono preamp section.

I have heard that H/K usually is good with tuners (I'll test it to see about its reception), plus its built in phono preamp section seems to sound equal to, if not better, than the $15 off ebay Realistic (Tandy Corp./Radio Shack) Phono Preamp I was using to run my vinyl.

What I really need now is a nice component rack...the stacking business no longer works with 3+ components...it looks ridiculous!