Upgrading thepower supply capacitors and rewiring with braided OFC cable.
telefunky
Posts: 3
Hi, My n-name is Telefunky and I'm from Hampshire, UK. I'm new to this forum so if I've posted this in the wrong place I'm sorry.
I would like some help. Some years ago I had a 1970s Rotel Transistor Amp, I think it was a RA???(insert number) any hoo I had the power supply capacitors upgraded and it was re-wired with shielded OFC Braided cable by an amateur HI_FI enthusiast. It sounded great after this inexpensive upgrade but alas has long since gone to transistor heaven.
So my question, do I copy the values of the o.e when replacing the psu caps? Do I use the best quality I can afford? Is it best to do this to a simple transistor amp with no built in tuner or does it not matter. ( I guess it does 'cos a modest Tuner/Amp will have hundreds of cheap and nasty components for the sake of the many erroneous functions needed for the product to appear to be "Good Value"
My old Rotel had a source selector, Volume, Bass, Treble, Loudness, and a Power Switch. It responded very well to the upgrades and the dynamics of the frequency range were cleanly defined in the same way real life ambient sounds are.
Some music was out of this world, Zappa studio albums like "Apostrophe" and "Joes Garage with properly tuned drums, toms and snare, delighted the listener with what sounded like an impossibly slow widened square wave turned thru 90 degrees. Panning with good/speakers x-over coils was 10 times better after the mods.
Yes I know I should get some valve bi-amps but trannies can sound o.k for most use.
I pay Homage to the technicians on this site, for your task is a noble one,'cos u create audio illusions for the human ear. Even a high-hat sounds great "tisch-tish-****-****-****" thru good Hi-Fi
Cheers
TelefunkenU-47
I buit my speakers with the help of my friends testing facilities , nothing too silly, in fact as cheap as I thought I could get away with.
A)s Vistation Ribbon Tweeters,
Morel MW142 75mm aluminium Hexatech v-coil Woofers, 35mm bass port tube, Visation film cap&graphite coil x-overs tuned to computers analysis after initial build, wired with OFC silicon cable in computer designed 35 liter cabinets that I built from 1" Oak laminated SMDF with full mitred joints and flush fitted units.
B)s Visaton G20 FFL Tweeters, Visaton W100S midrange, Morel MW142 Woofer, X-Over tuned as before and fitted into 55Litre Cabinets sprayed with auto paint black, this time Midrange at the top , tweeter in the middle etc. 2X 20mmby60mm Port Vents either side of the tweeter.
The A set look like something from the 70s and the B set, late 80s just after the ghastly plastic fake wood look faded out and the "shows up dents and dirt" black was popular. Still, they sound great at modest volume levels.
I would like some help. Some years ago I had a 1970s Rotel Transistor Amp, I think it was a RA???(insert number) any hoo I had the power supply capacitors upgraded and it was re-wired with shielded OFC Braided cable by an amateur HI_FI enthusiast. It sounded great after this inexpensive upgrade but alas has long since gone to transistor heaven.
So my question, do I copy the values of the o.e when replacing the psu caps? Do I use the best quality I can afford? Is it best to do this to a simple transistor amp with no built in tuner or does it not matter. ( I guess it does 'cos a modest Tuner/Amp will have hundreds of cheap and nasty components for the sake of the many erroneous functions needed for the product to appear to be "Good Value"
My old Rotel had a source selector, Volume, Bass, Treble, Loudness, and a Power Switch. It responded very well to the upgrades and the dynamics of the frequency range were cleanly defined in the same way real life ambient sounds are.
Some music was out of this world, Zappa studio albums like "Apostrophe" and "Joes Garage with properly tuned drums, toms and snare, delighted the listener with what sounded like an impossibly slow widened square wave turned thru 90 degrees. Panning with good/speakers x-over coils was 10 times better after the mods.
Yes I know I should get some valve bi-amps but trannies can sound o.k for most use.
I pay Homage to the technicians on this site, for your task is a noble one,'cos u create audio illusions for the human ear. Even a high-hat sounds great "tisch-tish-****-****-****" thru good Hi-Fi
Cheers
TelefunkenU-47
I buit my speakers with the help of my friends testing facilities , nothing too silly, in fact as cheap as I thought I could get away with.
A)s Vistation Ribbon Tweeters,
Morel MW142 75mm aluminium Hexatech v-coil Woofers, 35mm bass port tube, Visation film cap&graphite coil x-overs tuned to computers analysis after initial build, wired with OFC silicon cable in computer designed 35 liter cabinets that I built from 1" Oak laminated SMDF with full mitred joints and flush fitted units.
B)s Visaton G20 FFL Tweeters, Visaton W100S midrange, Morel MW142 Woofer, X-Over tuned as before and fitted into 55Litre Cabinets sprayed with auto paint black, this time Midrange at the top , tweeter in the middle etc. 2X 20mmby60mm Port Vents either side of the tweeter.
The A set look like something from the 70s and the B set, late 80s just after the ghastly plastic fake wood look faded out and the "shows up dents and dirt" black was popular. Still, they sound great at modest volume levels.
Post edited by telefunky on
Comments
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Welcome to the forum.
What amp are you thinking about upgrading, another Rotel? If so and IMO, you'd be better off buying a high end SS amp to start with. Since you're in England, may I suggest Musical Fidelity.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Cheers Guys, what a friendly welcome even though I typed on and on.
Two more things when I tweaked my old Rotel my mate said get a new volume potentiometer that has distinct increments controlled by resistors as this was better than the not very exact method of the carbon track. Is this a good investment? Could save a few quid on Servisol tho!
Second PSU caps; I take it that the price range is from tens of pence/cents to several pounds/dollars per item or is there a cap-king made from materials that cost 1000% more but only perform 5% better. 'cos the law of diminishing returns is the privilege of rich hi-fi snobs.
I don't mind if it has the legend POWER CAP Emblazoned on the side in some kind of High-Voltage font like some kinda BS conspicuous Sub-Woofer branding that teenagers love so much. -
The stepped attenuators are a reasonable upgrade but I wouldn't spend the extra quid... Did I use the term quid appropriatly?
Welcome to the forum!
madmaxVinyl, the final frontier...
Avantgarde horns, 300b tubes, thats the kinda crap I want...
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wouldn't spend the extra quid... Did I use the term quid appropriatly?
Yes, indeed.
Thank You my Brethren Cousins. With so much flashy electronics out there that is NOT Hi-Fi its good to know theres a site like this.
Im from Hampshire, which like Dorset and Devon are Farming Counties. Hampshire and Devon have mostly arable farms, so the countryside looks all pretty, a green patchwork quilt of lots of tiny farm and woodland copses sprinkled about. Dorset is dark brown quagmire of piss mud and **** mud, thats right its mostly Dairy Farms. So I dont sound like Bart Simpsons impression of an 18th Century of a Cockney Shoe Shine Boy more like the Southern Farmers accent. Including of all places Plymouth. So a bit like some of the founding Fathers before they started doing that John Wayne thing but not as intense and we sometimes drop the odd vowel. -
Welcome to the forum. I like your name.
Like F1 mentioned, you're probably better off buying a high end amp. If you buy another Rotel, pay parts and labour to your technician, you may be spending as much as a better quality amp like MF. Also, if you buy new and have your techie work on the amp, you will void the warranty.
Maurice -
Like F1 mentioned, you're probably better off buying a high end amp.
However I heard about http://www.amazingwatcher.com which is a free website that will watch items for you on Amazon and let you know when amazon has them in stock at regular retail price.:) -
^^ReportedHT Rig
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It's not that I'm insensitive, I just don't care.. -
Welcome aboard!Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
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To answer the original question....blanket upgrading ps caps may or may not be the place to start. Usually, coupling caps are a better investment, for instance. Or the attenuators, as you mentioned.
Raising the capacitance values of the caps depends again, to some degree, on the circuit. If it's all solid state, then usually. The last cap in the ps is the one that effects sonics most. Something like a Blackgate powertank there might pay, as they are excellent sonically. Generally, high performance caps mean upping the temperature rating and more importantly getting better ESR ratings, which mean they perform better with higher frequency trash getting to them.
Which leads to another place for very effective upgrading...better rectifier diodes. Soft recovery diodes throw much less trash into the ps and the audio.
CoolJazzA so called science type proudly says... "I do realize that I would fool myself all the time, about listening conclusions and many other observations, if I did listen before buying. That’s why I don’t, I bought all of my current gear based on technical parameters alone, such as specs and measurements."
More amazing Internet Science Pink Panther wisdom..."My DAC has since been upgraded from Mark Levinson to Topping."
