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Rowe / AMI 45 box static
Posted: Fri Oct 17, 2014 2:42 pm
by mike11
I recently picked up a R87 45 box, got it running and it plays and works nice but the tops speakers are staticky, I've tried a different speaker with no change... wondering where would be the next place to look??? dirty records ?? they look nice and clean though..... Replace needle ???? what else ???
Thanks
Re: Rowe / AMI 45 box static
Posted: Fri Oct 17, 2014 4:56 pm
by Ron Rich
Mike,
Not being able to hear it, I really don't know --
Try the following:
Make a selection and once the needle is on the record, lift it off--Do you still hear "static" ?
Ron Rich
Re: Rowe / AMI 45 box static
Posted: Sun Oct 19, 2014 6:44 am
by mike11
Yes it's only with the needle down ...... Not clear at all like a radio with the tuner just off where it needs to be
Re: Rowe / AMI 45 box static
Posted: Sun Oct 19, 2014 5:08 pm
by Ron Rich
Mike,
First thing I would do is check the needle pressure--2nd thing I would do is purchase a genuine, Shure brand needle, for it.
If that does not "clear it up", you probably have internal problems in the amp. Ron Rich
Re: Rowe / AMI 45 box static
Posted: Sun Oct 19, 2014 5:18 pm
by mike11
Ron I'm not familiar with how to set or adjust the needle pressure .... I've just recently started playing with the 45s ...... I have a needle on it way here it'll be here tomorrow ..... I'll put that in and report back...... If I poke into the amp I would imagine at min it will need electrolytics
Re: Rowe / AMI 45 box static
Posted: Sun Oct 19, 2014 6:33 pm
by Ron Rich
Hi Mike,
Well, first, you need to purchase a Neuses, or similar, pressure gauge. (suppliers listed above, stock these)
If you have purchased an "aftermarket" needle--SOME of them are poor, others "fair"--I find them to be very inconsistent in "quality control"--Hopefully, the one you get will be OK--
Try it with a record you don't care about, first--
You also might consider lifting the tone arm up, and oiling the shaft--I use nothing but 20 wt.ND motor oil, anywhere, in that phonograph--
Ron Rich
Re: Rowe / AMI 45 box static
Posted: Sun Oct 19, 2014 7:11 pm
by mb9513
Mike 2 other areas to check on Rowe's. the speakers themselves. if the voice coil gets out of alignment and rubs the magnet. the only way to check that is to put a known good audio signal to it. Or you can gently push the cone and listen for rubbing. be very careful as you could damage the speaker by pushing to hard. As ron said the amp may be the culprit. I have seen, in the amp, the output transistors are each protected by a fuse. if you loose one of the fuses then only one output transistor works and the sound is crappy. they are located on the underside of the driver boards, so you can't see them by looking all around the amp. remove and check all 4 fuses and their connections. Do not place a larger fuse in it. the amp is built with modules that all have plug connectors, as the age of this box, being almost 30 years old, it needs ALL of the connections in the amp checked and cleaned. "De oxit" all of the slide swithces and pots in it too. Mark
Re: Rowe / AMI 45 box static
Posted: Sun Oct 19, 2014 7:21 pm
by Ken Layton
Don't forget the many "cold" solder joints on the amplifier's circuit boards, particularly at the connector header male pins.
Re: Rowe / AMI 45 box static
Posted: Sun Oct 19, 2014 8:00 pm
by Ron Rich
Ken,
Great point--Rowe's are "FAMOUS" for that !! Also, amongst their claim to fame, are the "connectors", themselves--
On those models they used round "pins" on the "hedders" but (inexpensive !) "flat pins" in the plug housings ?? Later models used flat pins, on both, but really did not improve a bad situation, much-----"pins" in the housings need to be removed/cleaned, and reformed !
As for "replacing the fuse"--
The Rowe manual states that a blown fuse can be replaced on these amps, if the out-put transistor is changed--well, yes, if you are "lucky", and only the out-put is bad. I find this to be the case only 30-40% of the time. I would advise, that if blown, the output must be changed, AND, the driver board be examined for "burned resistors"--Most of the time, these are visible, and they along with "associated items" must be replaced--however if you see none, IMHO, it is best to check that board before placing it back in service ! You will also need to re-check bias, if you have changed any parts, or, just to be safe--
In General--and especially on these amps, I do not advise "just replacing a fuse"--On very "rare occasions" (my guess 1 % of the time), a fuse will just "get old", and blow for no reason--By replacing a fuse, even if the correct type and size, generally, you risk adding to the destruction. Therefore, I suggest that testing of the driver board be done--
Ron Rich
Re: Rowe / AMI 45 box static
Posted: Mon Oct 20, 2014 12:12 am
by mike11
I'm pretty familiar with the amps I've done a cpl rebuild ons the newer ones from the cd boxes ...and totally agree..... Fuse is is from a bad output trans and when they go they wipe out a few resistors along the way ..... You can literally follow the smoke trail to them .... Lol .... As for now I'm gonna say the speakers are ok cause I did swap then and the condition exists. In the machine and sends it to what ever speaker it has hooked to it ..... Kinda leaving me with 3 things .... Needle, cart and or amp at this point ..... I'll yank the amp tonight and reflow that and see where we end up .... Then to the tone arm of the probs still there ..... I'll keep you guys in the loop
Thank you
Re: Rowe / AMI 45 box static
Posted: Tue Oct 21, 2014 12:17 pm
by ami-man
Hi Mike,
I would check to make sure that the cartridge is wired in phase as it should be on the 125/130 watt amplifiers.
I agree with Ron you had better check that tracking weight.
Being as the noise goes away it is more than likely a connection/cartridge/needle issue rather than the amplifier, you can test the amplifier by putting an input into the auxillary input such as a CD output or any music source of around 500 to 600mv.
Regards
Alan
Alan Hood
ami-man
UK
Re: Rowe / AMI 45 box static
Posted: Wed Oct 22, 2014 7:57 pm
by mike11
I replaced the needle n cart.... Sounds a lot better but top speakers still sojnd like shit lol .... Could be blown due to their age or I'm just not used to the sound from a vinyl box I'm usually working on cd stuff that's always clear as a bell......
Re: Rowe / AMI 45 box static
Posted: Thu Oct 23, 2014 5:50 pm
by Ron Rich
Mike,
Doubt they are "blown"--is the sound system (speaker connections) set-up as per the manual ? Ron Rich
Re: Rowe / AMI 45 box static
Posted: Thu Oct 23, 2014 7:16 pm
by mike11
Ron
I have no idea ..... I don't have the manual for this machine. Only the mans for the newer ones .... Nothing in there appears to be anything other than the factory setup but that's just my opinion ... The cart and needle did clear up most all of the noise .... Before and after the song the noise is minimal very minimal which I would attribute to maybe light dust on the records..... When the speakers are playing though they are staticky ..... I agree with you it's prob not the speakers since I did hook up another known good one and it also existed in that one .... I did check and they are hooked up correctly as far as polarity ... I really don't know where to look next .... Needle to cart to amp to speakers .... I kinda covered the whole path of signal all the way up ... Only thing I haven't done was reflow all the pins on the amp but have tried wiggling and playing with all connections as it's playbg and that made no change .... Btw the cart I got was a used one it was all I could find... So we can't completely rule that out .... You know these a lot better than I do ... What would you do or think next ???
Thanks
Re: Rowe / AMI 45 box static
Posted: Thu Oct 23, 2014 7:55 pm
by Ron Rich
Mike,
Going from my great,but not too long, memory--
Without any other then the cabinet speakers connected--
Violet, and Pink wires are the two woofers, which should be connected to "E-6" --one on each channel--(at the terminal strip near the output trannys)
The other two (Brown ?) and Red, should be connected to E-5. The red on on the side with the pink woofer speaker.
Ron Rich