Hacker Gondolier Caps

[kirstyd]

I cant seem to find any 50NF caps anywhere, can anyone please tell me if the ones in the photo will do to replace caps 6&7. I also have a new 50+50 can to replace caps 11 & 12 but it has a plastic coat, will this be a problem?

[G6Tanuki]

47nF is the "harmonized" step-scale version of the legacy 50nF [see here: https://en.wikipedia.org/wiki/E-seri...ferred_numbers for the mathematical logic underlying the numbers involved]

They'll do just fine.

[kirstyd]

Thank you very much. Will put them in tomorrow.

[Nickthedentist]

Yes, they're perfect in every respect

[David G4EBT]

It might be worth mentioning that while you're at it, that if you haven't already done so, you may wish to consider replacing the cathode by-pass capacitors, C3, C5 & C10, which - if they aren't already duff - will be well past their best. All are 50uF so modern equivalents are 47uF. You can check the working voltage on them - usually 25 to 50V. Modern ones will look puny by comparison, but will be up to the task.

As to the twin 50uF reservoir/smoothing capacitor can being plastic coated, that will only be a problem if the existing one uses a clamping clip onto the can as the ground connection, rather than a negative tag. Your new unit will most likely have a red, yellow and black tag. The black tag must be grounded. The red one will be the outer cap in the can and if it isn't stated on the can, ('Res') that will be the reservoir cap, (which is connected to the cathode of the rectifier valve), which has to work the hardest - the yellow tag is for the smoothing cap (which comes after R21 - the 200 Ohm resistor). Sure, they're both 50uF and will work whichever one is used for smoothing or reservoir - it's just a matter of being kind to your caps, (as you would to your cats, if you have any!).

Hope that helps a bit.

[kirstyd]

Fitted the new caps today and all seems to be working OK but there is some hum when turned up loud. Some years ago [20+] i fitted a new cart to this machine because the original had packed up on one channel. The one i fitted is an ACOS GP104 with just three connections. I am just wondering if that one has developed a fault as well. The photo of the date was written by me some years ago when I found that date stamped under the amplifier. The blue caps and the two black ones are some I fitted some time ago because one of them was leaking so I decided to do them all.

[Edward Huggins]

There really should be no apparent hum at all on these, even at 75% volume control rotation. If the hum is increasing with volume then it may be from the pick up lead screening. The Acos 104 was one of the first stereo cartridges and will be over 45 years old. This might need replacing. I guess you are using this as Stereo bridged to Mono without a stereo add-on amp.

[kirstyd]

I will try another cart and see how it performs. I have two other units that use the 104 ACOS. They are in good order so to save messing with the cart connections I will try one of those.

Will let you know how I get on.

[kirstyd]

Just a quick thing, but while messing with this machine tonight I accidentally touched the pick up leads together [that's the blue lead to earth] and the hum disappeared altogether.

[Edward Huggins]

That might be simply because you've shorted out the input.

[kirstyd]

Yes Edward thats exactly what I did and the hum disappeared just a very faint hum at full volume. I will experiment with a few cartridges at the weekend and see what happens.

[Edward Huggins]

If you are to try out other cartridges, make sure you just use medium-output types.

[kirstyd]

Hi all.

Well I think I have finally cured this thing. First I fitted a new cartridge and although that improved the sound the hum [or should I say buzz] was still there so after checking everything I have done I finally found the fault. As those of you in the know will know the tag strip under the deck has five tags the two outer being pick up for the two channels the three inner being joined together, only on my machine they were not. Although there was a short bit of wire in place it had numerous dry joints once freshly soldered the hum was gone. Also the thin leads coming from the cart have tiny spade connectors that were loose I gave these a little squeeze and everything was fine. Thanks again for all the tips everyone. That's that one sorted.

I have another Gondolier slightly older that has the Garrard 3000 deck in it. I have also fitted this one with a new BSR SC11 cart and while it works OK the bass is excessive even for a Gondolier it's so bad the speaker makes a cracking sound when turned up reasonably loud even with the bass turned right down. Any ideas guys?

[Edward Huggins]

It may not be a speaker (they rarely fail) or an interestage fault, but a possibly a power supply problem causing HT starvation when you increase the volume.

[Nickthedentist]

As a starting point, you could swap the two amps over temporarily to rule out the cartridge and speaker.

[kirstyd]

i will swap the amps and see what happens .

[kirstyd]

Hi all
had another chance to look at this over the weekend resulting in me swapping the amps as suggested and sure enough the fault is on the main amp .and that was when i noticed the difference in the electrolytic caps .I have taken two photos of the caps in question .The photo with the smaller blue caps is the amp thats working well .the photo with the black caps is the poorly one now is it me or has one of them got caps fitted the wrong way round?

[Ted Kendall]

Yep, that looks like it. The negative end of jap electrolytics is generally the one they indicate - so just to take an example, the middle three are the wrong way round. That would cause some interesting effects...I'd say replace them all, the right way round, and see if that clears it.

[kirstyd]

Thanks Ted. Will swap em round and see what happens. Cheers

[kirstyd]

Had another look at this today .Started by putting those three caps the right way round but to no avail the fault persists .I have since systematically swapped every thing i can [valves from good one into bad one and the reverse .No good ][Amp from good one into bad one ]works perfectly proving that the speaker and the tone set up are fine so the fault is on the amp.next i did some voltage tests and there are differences also there is some wax on the transformer of the bad one but its voltages are the same as the good one suggesting that its ok .had enough for today .Sometimes you just have to take a rest then start with a fresh mind .Will double check those voltages tmro and let you know what they are