NOS Mallory capacitors for Rhodes Piano

[Skiroy]

I want the original mallory capacitors or something very close to the originals(any advice on specs on new Mallories). Anyone thats says that Fender just used what ever they could get has no credibility so please save it. I dont mean to be rude but even if they did get what ever they could get cheap those caps were made differently then today. THEY SOUND DIFFERENT. I proved this by replacing one channel with the cheap caps in Vintage Vibes rebuild kit,which I dont recommend. I recorded each channel. The Original caps sounded way better,smoother ,richer and had mojo. The VV caps sounded flat and sterile. Of course the older caps sound different from ageing but there is definitely more going on here than that. Why else would Amp tone freaks replace there caps with Orange drops or mallories instead of some generic cap from mouser(what VV uses)?

Matter of fact I listened to most of the restored Rhodes VV did on youtube. I emailed them and it just so turned out that the ones I wasnt crazy about the tone for had the electronics rebuilt by them and the ones I drooled over had the original electronic components. I am not saying that they are not very knowledgeable and good at what they do but they are business and they are selling cheap components at quality prices. So any info from someone that is experienced with this and can help me with getting as close to the original caps as far as materials and construction, I appreciate it.

[Rhodesplyr]

What brand/type does Vintage Vibe provide? There should be some identifying marks on them. If you're not good at parts identification, post a picture.

Also, you need to tell us if you're talking about the Peterson/80W Suitcase Piano or the 100W Suitcase Piano, as these are different. If you want a detailed, specific answer, as you seem to, you need to provide us with detailed, specific information, too.

The originals from my 80W Suitcase were Mallory FP cans, and I have seen Mallory FP cans from the 70s last a long time, but they also haven't made them for a long time.

And, forgive me for the suggestion, but if your original caps still function adequately and sound better, why not keep using them? If one shorts, the fuse should blow and protect your power transformer.

[Steve Conner]

Sure, just put the old ones back in. At least you know they worked.

If you're talking about electrolytics (the type of cap that comes in an aluminium can with a bung in one end) "NOS" ones can be a major gamble, I wouldn't buy them. They are known to deteriorate with age especially if left sitting on a shelf.

Maybe your electrolytics have gone crappy and you like what that does to the sound. Rhodesplyr, did these things use electrolytic coupling capacitors?

[J M Fahey]

The Original caps sounded way better,smoother ,richer and had mojo. The VV caps sounded flat and sterile.

Agree with you.
New ones have no Mojo.

Why else would Amp tone freaks replace there caps with Orange drops or mallories instead of some generic cap from mouser(what VV uses)?

You called them freaks, not me.

[diagrammatiks]

use teflon caps.

[Rhodesplyr]

Maybe your electrolytics have gone crappy and you like what that does to the sound. Rhodesplyr, did these things use electrolytic coupling capacitors?

Yes, they used many electrolytic coupling capacitors in the preamp signal path. For some reason, I only considered the main power supply filters, which are Mallory FP units that tend to be fairly reliable.

The signal path coupling caps, on the other hand, are the white plastic jacketed Mallory electrolytics that *do* tend to fail frequently, especially the ones in the tremolo oscillator circuit. The most common value is a 5uF bipolar. A axial lead replacement used to be available in the Sprague/Atom line, but these may be hard to find now. My current favorite bipolar electrolytics are those in the Nichicon ES series.

This may be a classic example of someone liking the way something sounds due to deteriorated parts.

My repair policy is that if you *love* the way your amp sounds, then, by definition, there's nothing wrong with it. I don't care if it's on fire :-)

P.S. The Sprague part number for their 5uF axial non-polar electrolytic is TVAN1303.1, but they will be hard to find. I would wager that they would be closest in construction to the Mallory originals.

[Skiroy]

Yes, they used many electrolytic coupling capacitors in the preamp signal path. For some reason, I only considered the main power supply filters, which are Mallory FP units that tend to be fairly reliable.

The signal path coupling caps, on the other hand, are the white plastic jacketed Mallory electrolytics that *do* tend to fail frequently, especially the ones in the tremolo oscillator circuit. The most common value is a 5uF bipolar. A axial lead replacement used to be available in the Sprague/Atom line, but these may be hard to find now. My current favorite bipolar electrolytics are those in the Nichicon ES series.

This may be a classic example of someone liking the way something sounds due to deteriorated parts.

My repair policy is that if you *love* the way your amp sounds, then, by definition, there's nothing wrong with it. I don't care if it's on fire :-)

P.S. The Sprague part number for their 5uF axial non-polar electrolytic is TVAN1303.1, but they will be hard to find. I would wager that they would be closest in construction to the Mallory originals.

I was told it was a 80watt and the caps are white plastic mallories. I like how the originals sound but I can tell one side is different than the other. It is a little muddy in the mix compared to the other side which sounds alot more richer than the VV caps but I can tell are needing replacement in the near future. What are some symptoms of a cap going bad in the tremolo circuit? I had the left side of the Tremolo not coming on. I cleaned the POT and it worked again,but then later it stopped working so I replaced the POT. Still didnt worked. I replaced the Transistor and it didnt work until I turned up the Vibrato intensity. Now it works but occasionally doesnt work until I mess with the intensity. Not a lamp issue because both lamps work fine when vibrato is disengaged. Could this be a cap and are the 2 Blue NP caps the ones in the Vibrato circuit?


So the Nichicon ES are the best replacements in your opinion,not current Mallories?

[Rhodesplyr]

What are some symptoms of a cap going bad in the tremolo circuit?

Well, tremolo not working can be a clue... :-) These are always the first components that should be replaced if it doesn't work.

Could this be a cap and are the 2 Blue NP caps the ones in the Vibrato circuit?

As I indicated above, if they haven't been replaced, it's likely an electrolytic capacitor problem. The oscillator circuit charges and discharges them constantly, which tends to be hard on electrolytic types. The second most common failure would be a bad transistor. These act as oscillators and On/Off switches in the circuit. The blue epoxy-coated capacitors are polyester film capacitors, which rarely fail, especially at solid-state voltages. Electrolytic capacitors are prone to age-related failures; most film caps are not (though that is a generalization).

So the Nichicon ES are the best replacements in your opinion,not current Mallories?

One thing I think you don't understand--and that you need to understand--about the electronics parts supply business is that it changes constantly and rapidly. Companies abandon product lines and start new ones, and they get bought and sold. Keeping track of all these changes is one of the challenges of being a tech or amp manufacturer. Mallory, as far as I can tell, is now owned by Cornell Dubilier, and only a few types of electrolytic capacitors are still sold under the Mallory name, mostly higher-value computer grade units. They no longer make or sell capacitors in the ~5uF range, and they haven't made those white plastic jacketed types for a very long time.

The Nichicon ES are my favorite non-polar electrolytics, in general, but the Sprague Atom units I mentioned might stand a chance of being more similar to the Mallory originals. Also, you won't find a 5uF cap in the Nichicon line; 4.7uF is now the standard value. The value difference isn't particularly significant. And Nichicons, like most electrolytic capacitors these days, have radial leads. Axial lead electrolytics are made in smaller numbers and tend to be more expensive as legacy/replacement parts.

You can get the Sprague Atoms here:

TVAN1303.1 - Sprague Electric - CAPACITOR, 5 MFD, 50VDC, AXIAL ALUMINUM ELECTROLYTIC, +-20% TOL NON-POLARIZED

That's about 10x the price of the Nichicons, but they are apparently available.

[Skiroy]

Please excuse my ignorance but I have a few fundamental questions.

1. Does changing the values as far as voltage or mismatching different Voltages of Capacitors effect the tone in anyway? I have some that are 50V while others are 25V. Would it be more accurate to stick with these voltages?

2. I only see 2 5uf caps while the rest are 1,10,50,100 and 8 MFD caps on my preamp. Are you saying I should use the Sprague Aluminium Electrolytics for all of these? And can I use Non-Polarized Caps in the place where my preamp has polarized caps?

[gbono]

1. Can't speak to the "tone" issue but aluminum (and tantalum) electrolytics should have a 50% working voltage derating for reliability.
2. Sounds good to me (pun intended).

Remember that new capacitor designs (aluminum, ceramic, etc) can have a 10x improvement in ESR. I won't comment on the subjective nature of listening test results but just reworking a 30 year old component in a 30 year old piece of gear might cause issues unrelated to the "new" capacitor.

I've worked on a few Rhodes pianos and find that proper care and feeding of the harp and its related electro mechanical components outshadows the subtle changes of caps and transistors in the signal path.

[Jazz P Bass]

Please excuse my ignorance but I have a few fundamental questions.

1. Does changing the values as far as voltage or mismatching different Voltages of Capacitors effect the tone in anyway? I have some that are 50V while others are 25V. Would it be more accurate to stick with these voltages?

2. I only see 2 5uf caps while the rest are 1,10,50,100 and 8 MFD caps on my preamp. Are you saying I should use the Sprague Aluminium Electrolytics for all of these? And can I use Non-Polarized Caps in the place where my preamp has polarized caps?

#1
The voltage rating of the capacitor is the value that the cap itself can withstand, before something internal goes bad.
You rate the cap (+30%)for the maximum expected voltage the circuit involved in will see.
#2
If a circuit calls for a polarized or a nonpolarized capacitor, it is "generally" a good idea to stick with that type of cap.
There are certainly exceptions.
It all depends on the circuit.

Please keep in mind that you are asking some very obscure questions without a reference to a specific circuit or application.
Can you post any schematics?

[Rhodesplyr]

1. Does changing the values as far as voltage or mismatching different Voltages of Capacitors effect the tone in anyway? I have some that are 50V while others are 25V. Would it be more accurate to stick with these voltages?

Voltage rating does not affect tone.

2. I only see 2 5uf caps while the rest are 1,10,50,100 and 8 MFD caps on my preamp. Are you saying I should use the Sprague Aluminium Electrolytics for all of these? And can I use Non-Polarized Caps in the place where my preamp has polarized caps?

You can, but there's no reason to use non-polarized caps in other positions.

At this point, I feel the need to say that if you're going to attempt this sort of work, you should take the time to educate yourself about the basics. In other words, these are such basic questions that no one doing this kind of thing should need to ask them. I'm not trying to sound harsh. I'm saying that the information is out there on the internet, and you can google it and read it on your own rather than asking people in online forums to type it out for you.

[Rhodesplyr]

Please keep in mind that you are asking some very obscure questions without a reference to a specific circuit or application.
Can you post any schematics?

The circuit he's asking about is the Rhodes Suitcase Piano preamplifier, the earlier 80W "Peterson" version as seen here:

http://www.fenderrhodes.com/ch11/fig11-8.jpg

The +25V supply to it is regulated in the power supply module located in the speaker enclosure, connected by a four-pin cable. The two light-bulb/LDR units provide the classic Rhodes stereo-tremolo effect via two separate power amp modules in the lower section.

The non-polar electrolytics are used where you'd expect them to be, in the signal path between transistor gain stages. The rest, except for the single 1uF cap, are there for power supply decoupling.

[Skiroy]

I understand your point completely but at this point I dont really need to know much besides which caps to buy(If someone could be kind enough to spell it out for a idiot) and soldier them on the board. I dont plan on doing this on a regular basis just to get this Rhodes done and I am finished with my hand in the world of electronics. I am fully capable of soldiering.

Lastly do the brand,quality of resistors and diodes have any effect on the tone? I already used the VV resistors without any noticeable tone change but I was thinking about also using the diodes and then tracking down the Caps you suggest with the proper polarity,voltage and capacitance values as are exactly in my preamp.

And yes my preamp is the 80 watt version as you poster pointed out.

[J M Fahey]

IŽd suggest you buy new very high quality caps from big, advanced companies, which have both the know how and the machinery to back what they produce.
Not dusty over ripe NOS parts or "hand made in the garage" exotics.
Some brands I trust (for good reason) are Vishay (Sprague/Mallory), EPCOS (ex -Siemens) and some of the good Orientals, such as Panasonic or Nichicon.
There are certainly other good ones too.
What I can't trust is something that *was* very good, no doubt ... 30 years ago.
Good luck.
jm2c