Quantcast
Channel: diyAudio
Viewing all 93807 articles
Browse latest View live

Newbie questions on a multi-way speaker

$
0
0
Hi there, first post from someone who has been lurking here for awhile.
I figure almost every new guy ask a silly question, or something that has been asked a thousand times before, so I've been saving my first post for this occasion. :p
The post will be long and 'not to the point', but I appreciate anyone that takes the time. :)

Background:
My current audio system has served me well, the amplifier (NAD 302) is almost 25 years old and the speakers (B&W DM309) 12 years or so, and I listen to music 2-12 hours a day as well as use them for movies. I credit this to a 'held back' sound, I was looking as substantially more expensive speakers but realized I would get tired of long hours of listning to them and would have needed more attention to placement in the room.
But, two things has happened, I've realized I want to run the audio from my TV to the speakers and I upgraded/built new sound system in my car that simply blew my home audio out of the water. Instead of rumbling bass I could hear the strings of the bass guitars of the same songs, and acoustic guitars has some air, and so on.
My questions is regarding multi-way speakers, but I'm looking at the whole system so I don't paint myself in to one corner. Your answer/thoughts can be to just the speaker design or the whole deal.

Positive things:
-I live in a house and have a good 300 meters to my neighbor.
-No wife or girlfriend that will complain. :D
-I'm eager to learn, and got the time to do so.
-I've got space to work in, and the ability to do so.

Negative things:
-Money is very scarce, this will take some time to complete.
-Listning position is pretty bad most of the time, as I use my PC as a media center for music and film and it's positioned on the opposite side of the wall of my TV/Speakers (so I listen to music from opposite room most of the time as I surf).
-That also positions my speakers at one end of the long side of the wall (5.5x3.7 M or 20sqM).

My thoughts so far:
-I need audio input from my TV (optical) and something from my PC (several options with my soundcard).
-I need to be able to control the volume, as the optic signal from my TV isn't level controlled.
-No matter if I use passive or active crossover a mic is a logical purchase.
-Cheapest solution seams to be a miniDSP 2x4HD, as I get the connections and volume control, as well as the ability to fine tune the system all in one package. (Combined with two 2-channel amps that will be DIY)
-I will most likely go with closed enclosure and bump up the low region with the DSP if needed, the new subwoofer in my car made me a believer. (I have modeled a lot of speakers in winisd to see how they behave as well)
-Making a pod for the tweeter (or tweeter and midrange) seems like time well spent to get away a little bit from baffle step, edge diffraction and so on.
-No passive crossover in speaker boxes, that allows me to go full active later, as well as making changes easier.

Questions:
1. My first though was to build a 2.5 speaker using two SEAS H1288-08 CA22RNX, with one of them on a 1:st order filter for the lowest region, and active crossover to something like a SEAS 27TDFC or ScanSpeak D3004/602010 (the ScanSpeak is interesting because of the small size for a pod).
But I'm slightly concerned with how the large CA22RNX will sound in the upper region (guessing crossover at 1800hz or so would be suitable).
2. Second thought is to build a 3-way, using passive crossover between tweeter and midrange, and active to the woofer (2.2 system).
Tweeters would be the same.
Midrange duty either SEAS MCA15RCY, or perhaps CA18RLY.
As a woofer the Wavecor SW270WA01 has looked the best in winisd for my price range.
As the woofer might need to be crossed over at a low(-ish) frequency, the larger CA18RLY maybe is better at extending down a bit compared to the smaller midrange.
3. I'm hoping a well matched set of speakers that has passive crossover could be fine tuned with the DSP and thereby making the passive crossover a more "straight forward" design, as I have understod that a passive filter can get really expensive (both parts and trial&error).
In the 3-way solution I would guess it's smoothing out the the upper region, possibly bringing it down to match the subwoofer in frequency respons.
But maybe I'm making it twice as hard... :confused:

You don't have to do all the legwork for me, I'm just hoping someone can point me in the right direction.
Thank you for your time! :)

Making a compact Sub without the info (cheap!)

$
0
0
I was given a Bush subwoofer from S21192. The unit had a 5" driver in a cabinet measuring 20cm x 20cm x 25cm. I replaced the driver with a 6.5" unit from an Acoustic Solutions AV-120.

Unfortunately, I do have the specifications for either drive unit other than the Acoustic Solutions AV-120 bottoms out at 48hz in a floor-standing cabinet.

The results are okay but the bass ain't going to trouble the neighbours. Because the cabinet is so small would I be better off removing the port and converting a sealed enclosure?

Or should I discard the port in favour of 2 x 4" passive radiators?

GBPC / KBPC rectifier bridge footprint ?

$
0
0
Hi all,

I must admit I did not spend hours on looking for it but quite some time and then I though someone had done the same before...

So, does anyone have a component footprint for the GBPC and similar generic rectifier series ?

TIA,

Max

WTB: 4x 6C33C (or similar) tubes

$
0
0
Hi All,
As the title says I'm looking to buy 4 of these tubes (6C33C, or one of the similar variants), I have paypal, venmo, or I can meet locally for cash if your in the USA - MA area.

Thanks for looking

Audax HM170C0 6.5" Woven Carbon Fiber Woofer

$
0
0
Does anyone have a matched pair for sale?

Texas Instruments PCM2902 SPDIF out

$
0
0
Dear all,

I've been browsing through the DIYAudio forum for ages.


A question.


How difficult is it to get SPDIF out from the Texas Instruments PCM2902.


Thank you very much in advance.

Cleaning Records

$
0
0
Your records should play with pretty much no ticks and pops. Ok, if your cat scratched your record all up, it's going to sound crummy and you can't fix that, but just normal ticks and pops are junk in the record grooves, and most of them can be gotten out. Some of this junk is in the record when it's brand new, it's not necessarily because your teenager was playing Frisbee with it.

Why do we clean records? Dirty records sound bad. Playing dirty records wears them out faster. Playing dirty records get your stylus dirty, and a dirty stylus wears your records out faster. At 20,000 hz, the bumps in a record groove are about .0001" to .00025" (a tenth to a quarter of a thousandth of an inch) (2.5 to 6 microns), depending on if you're in the outside or inside groove. These are seriously small features and a remarkably tiny piece of dust or junk can cause your diamond stylus to dig and chip them off. If we had the money, we'd like our records stored and played in Intel's latest clean room. If you clean your records properly, everything sounds better - vocals, drums, strings, everything.

There are a lot of ways to clean records, including cleaning machines which cost thousands of dollars. We're not going to spend that kind of money. If your daddy was a Carnegie or a DuPont, or if you're a Wall Street hedge fund criminal, then go ahead and buy the $4,000 Audio Desk cleaner and hire a certified British butler, preferably named Alfred, to wear a tuxedo and white gloves whilst he uses it on your incomparable collection of rare disks.

Perhaps you're at an estate sale and you see a 1930s Duke Ellington record - you simply must buy it. Unfortunately, when you open it up it looks like the previous owner loved it so much he took it into the WWII foxholes with him. How do you get this clean?

Here's the basic ways people clean records, in order of cost:
  • Dish soap and water. Time tested, marginally effective. Soap is a surfactant and also dissolves oils, so this sounds like a good system, but the soap leaves a residue in the grooves. Plain old water has a lot of surface tension - bugs can walk on it. A surfactant is a chemical that gets rid of the surface tension and lets the water flow into tiny nooks and crannies more easily. Tap water is filled with minerals, bacteria, fungus, bleach, birth control steroids, metals, and pieces of dead cockroaches - that's why we use distilled water. Not recommended.
  • Isopropyl Alcohol + water + dish soap. A common recipe is three parts distilled water, one part alcohol, a teaspoon of dish soap. Used by many. Over time alcohol will leach some of the chemicals out of your records - plasticizers - and your records will get brittle. Your stylus will chip away at the sharpest corners, and eventually the entire record will just snap. Plus the soap leaves a residue which will build up with repeated uses. Not recommended.
  • Carbon Fiber brush. Records are plastic and plastic holds a static charge. Charged stuff picks up dust, cat hair, dead cockroach pieces, whatever's around. Carbon fiber is a conductor which will take the charge and dust mites away with it. Just get one. Recommended.
  • Distilled water with surfactants, wiped off with a microfiber towel. The most famous surfactant for record cleaning is Tergitol, used by the library of congress. New microfiber towels must be washed a couple of times to get rid of lint. If you just use this you won't damage your records and they'll get reasonably clean. Recommended for already reasonably clean records. But we can do better.
  • Wood glue. Place your record on a turntable and put some wood glue on it. Run a bead of glue from the inner track in a spiral out to the outer track. You'll need to use a spiral spacing of about 1/4", so about 10-12 turns for the entire record. Then use a plastic straight edge to spread the glue evenly over the entire record surface. Let the glue dry - about an hour if sitting around, perhaps 15 minutes if it's in front of a fan. Then peel the wood glue off, bringing a bunch of stuff from inside the grooves with it. To peel the glue off, flex the record gently - you'll see the glue pop off in a small area. Gently flex around the record in a circle, then the whole glue piece should come off in one or two large pieces. You'll have some little stragglers at the outside and inside edges, you'll have to get these carefully. Then you'll have to clean the record carefully - running water followed by a careful G2 cleaning. Some swear by this technique. I found it worked ok, not great. Steam cleaning the record after the glue treatment resulting in further improvements. Hard work for so-so results. Not recommended.
  • A record cleaning solution + brush. Originally this was made by a Missouri company, DiscWasher. DiscWasher sold out to RCA, but the stuff still works. The current Discwasher liquid is D4. Some of their old employees have a new company, GrooveWasher, making an updated version which is slightly better. And there's about a dozen other companies making knock-offs, available at Amazon, EBay, Walmart, record stores. A notable alternative is Mobile Fidelity Sound Lab ONE Cleaning Solution. Any of these are recommended for maintenance cleaning. Not sufficient for a seriously dirty record. Helpful hint: the oak handle doesn't actually do anything useful. You can just use GrooveWasher G2 fluid and microfiber rags, like the ones you buy at Walmart, Harbor Freight, Costco. If you buy microfiber rags, wash them twice before using: when new they have a lot of lint on them. Highly recommended.
  • Enzymes. Some of the stuff on your records is organic crud from your hands, or, God forbid, chocolate and unidentifiable goo from your grandson's hands. And there's bacteria and funguses growing in the grooves - these little critters are everywhere on the planet that we've ever looked, seven miles down in the ocean, on top of Mount Everest, even several miles deep in the crust when we drill into the Earth. We've even found them clinging to the space station in complete vacuum. Life finds a way. Enzymatic cleaners will get this stuff off better than other fluids. Put the enzyme cleaner on your record and let it sit for ten to 15 minutes. Enzymes are biological molecules used to digest food - proteins - and are cooked up in vats of bacteria. We can't make these on our own with chemistry kits, only living cells know how to make them. So there's no magic proprietary enzymes, and the guys who make record cleaning supplies don't have the best bio labs in the country. Solvents like alcohol get in the grooves and work more or less instantly, but enzymes are complicated protein molecules, shaped more or less like little soccer balls, and only one spot on the protein is active. So you have to give the molecules time to spin and turn and latch onto the organic crud and break it up. You can cook up your own batch of enzymes with yeast and sugar and pineapple and a couple months, or you can buy an enzyme cleaner at any store - Walmart, Home Depot, Lowes, your local grocer. Cleaners that remove pet stains and odors are enzymes, and some cleaners just say enzymes on the label. Or you can spend two or three times as much for a bunch of audio marketing guys to buy a vat of enzyme cleaner from some big company and bottle it up as their own proprietary magic ultra-cleaner, carefully tested by their brother-in-law's ex-girlfriend who has a degree from the University Down The Street in biochemistry. You know, the same marketing guys who think you need $14,000 speaker wires, $6,500 RCA cables and $3,500 power cords. Highly recommended. The enzymes that is, not the $$$$ wires and cables.
  • Steam cleaning. A somewhat obscure but slightly popular method. Place the record on edge in your sink. I use a bit of bubble wrap so the record isn't actually touching the sink. Fill your steam cleaner with distilled water. Go over the record moving along at about an inch or two per second (a couple cm per second). After steaming do a good cleaning with G2 or D4. I recommend the PurSteam or Bissell hand held steamers, about $35 at Amazon or Ebay. This works well on seriously dirty records. If you're going to do a lot of this, get a label protector - a pair of acrylic disks with o-rings that screw onto your record and keep the label warm and dry. Highly recommended.
  • Wet playing. Put your record on a turntable. Spray D4 or G2 cleaner and some enzymes on your record. Wait for 15 minutes. Play the record wet. This is very hard on your stylus, and it's possible you will get liquids all over the turntable, so I don't recommend this for your real turntable. Buy a used turntable at Goodwill or get an ABS turntable from Hong Kong on Ebay, about $25. Use the $2 cartridges you can get from China on Ebay. Change cartridges every twenty filthy records or so, throw the old one away. This works well on seriously dirty records. I have concerns about the stylus driving some of the particles into the plastic. I'm not a fan of playing dirty records. Recommended.
  • Spin cleaners. There are several of these available on Ebay and Amazon for $35 - $200 with names like Studebaker, Spin-Clean, Album Washer, etc. I think they're all about the same. They do a noticeably better job than just using a spray cleaner and a brush - like a GrooveWasher - but are more trouble to use. They work by having a couple of microfiber brushes on each side of the record, then you spin the record through the brushes and cleaning fluid. Since the record is verticle the stuff tends to fall down instead of staying in the groove like when the record is horizontal. Recommended for deeper cleaning. They come with solutions which are more or less like Discwasher D4 or Groovewasher G2 fluid. I'd use the real thing - G2 - when you run out of cleaner, and add some enzymes too. Recommended.
  • Ultrasonic cleaners. There are several of these available on Ebay and Amazon for $200 - $4000. I haven't used them. They have a good reputation, so they must work reasonably well. Expensive, tentatively recommended.

Plan A:
My preferred way to clean "clean" records - place the record on a microfiber towel (which has been washed more than once), spray G2 on the record, wipe off with another microfiber towel. If there's still pops and crackles then it isn't really clean. Watch the record label - if the pop happens every time the label comes around, that's a scratch and you're screwed. But if they're random, most of them can be fixed.

Plan B:
My preferred way to clean "dirty" records:
  1. Clean with G2 or D4.
  2. Spray on enzyme cleaner. Let sit for 15 minutes.
  3. Steam clean. Dry with microfiber towel.
  4. Clean with G2 or D4. Dry with microfiber towel.
  5. Set the record on the turntable, use the carbon fiber brush to get rid of static electricity.

Sources:
web page, "thing to search for".
  • Carbon Fiber brush
    • Ebay.com, "carbon fiber record". About $4.50 from China, about $7.50 from the US.
    • Walmart.com, "carbon fiber record brush". About $9.
    • Amazon.com, "carbon fiber record brush". About $15.
  • Surfactant
    • Ebay.com, "tergitol". About $15 / quart. A quart is a seventeen lifetime supply.
  • Washing Solutions
    • Walmart.com, "groovewasher". Commando kit. About $15.
    • Ebay.com, "groovewasher". Commando kit. About $15.
    • Ebay.com, "groovewasher G2". 8oz, $20.
    • Ebay.com, "Mobile Fidelity ONE". 16oz, $20.
    • Ebay.com, "Phoenix Record Cleaning". 32oz, $25.
    • Ebay.com, "RCA D4+". 1.25oz, $15.
    • Ebay.com, "Revolv Supreme Clean". 32oz, $32.
  • Enzyme Solutions
  • Label Protector
    • Ebay.com, "Record Label Protector". About $20.
  • Cheap Turntable
    • Ebay.com, "ABS Turntable". $22.
    • Ebay.com, "phono cartridge". set sort price low to high. $2.
  • Ultrasonic Cleaner
    • Ebay.com, "Record Ultrasonic". About $200.
  • Spin Cleaner
    • Ebay.com, "Record spin clean". About $40.
    • Amazon.com, "Record cleaner". About $35.

Acknowledgements:
I got history, information and insights from the friendly guys at Groovewasher, whose business is just a few miles from me in Kansas City. I also got a lot of information from Dave Spriggs at Sofi's at the Stagecoach in Salado, Texas. Dave has been selling records for several decades, and has cleaned more records than I have seen.

How much THD are you allowing in your amp designes?

$
0
0
Up until now I use as little feedback as possible in my headphone amplifier designs (made 2 until now. The last one a 2 stage amp).
Did made a lot effort to get the THD below 1% but my second design is suffering around 3% THD at an output level of 700mVRMS into 300 Ohm load.
What is your target THD for your designs?

FS a pair of Magnequest Cobalt EXO-45 transformer

$
0
0
For Sale a used pair of Magnequest Cobalt EXO-45 output transformers. 5k primary with 8 ohm secondary.They where used in a 71a amp for a short period of time.
My selling price is $700.00 for the pair plus shipping

For Sale a used pair of Magnequest chokes BCP-15, They where also used in a 71a amp for a short period of time.
My selling price is $120.00 for the pair plus shipping
Attachment 800859

Attached Images
File Type: jpeg CoBalt EXO-45.jpeg (640.0 KB)

Combining Zobel network with feedback network

$
0
0
An idea I had while doing noise analysis on an amp design:



Click the image to open in full size.
The idea is that capacitive divider provides a low-noise alternative to resistive feedback network at higher audio frequencies, yet capacitively loads the amp output - however a Zobel network is already present, so it can share that duty as part of a capacitive feedback network.


This relaxes the need to use low value feedback resistors for noise-performance (except perhaps for LF).

WTB: IAN’s SPDIF interface+FIFO+Clock boards

$
0
0
I am looking for a solution to convert SPDIF output to I2S for my first DAC project which will be based on ryanj’s D3 board.

I’d like to keep it as simple as possible.

I’d rather it was one of Ian’s as they seem well supported.

Ian’s 2020 group buy hasn’t started yet, so I figured I’d see if anyone has a SPDIF setup they’d like to part with as I don’t need the latest and greatest for a first DAC attempt and I’d like to save a few bucks as this project’s cost is adding up fast.

Ian states that I need a FIFO in order to use his SPDIF Interface board. The SPIF manual also includes a clock board in its SPDIF FIFO example.

I’d prefer to follow the manuals example.

So far I’ve been contacted about a SPDIF board that is available, but I’d be interested in buying any or all of the boards mentioned.

Feel free to PM me with what you have for sale and the asking price.

Thanks very much.

SEOS-12 Synergy / Unity

$
0
0
I've read a lot of Synergy threads but I still don't know what it takes to make one from scratch.

Aside from a pair of SEOS 12s, I have laying around:
Faital Pro 3FE25
Dayton DE250 clones (mylar)
Seas P21RE
blowout PE 6.5" polycones
3" Aurasounds, and a few other randoms.

I'm fine with buying new drivers. Keeping it on a budget would be nice. Cost of BB ply, CNC, and XO parts will get me if the drivers don't. (I live in an apartment, no saws or routers)

Here are my requirements / constraints:

-I don't need high output. I listen at low volume levels.

-Passive XO. I have miniDSP HDMI but I want to use the speakers as part of a home theater. So one channel each.

-Sealed bass cab. I have two Seas P21RE that deliver as much bass as I need. I'd like to use them. Was thinking of using miniDSP just to match the woofer and synergy levels while still having them occupy just one channel via passive XO.

-I use planar tweeters currently and really like them. I like what Patrick Bateman is doing with getting HF extension in a Unity. I'd like to have that, but if the cost of admission today is just going with the DE250s I have then I'm fine with that.

-It's gotta be easy on the ears. I find a lot of speakers, especially those with metal drivers, to be fatiguing and make me want to turn it off.

I have a umik for measuring.

I have seen Bill Waslo have good success doing this with the 15" SEOS. But I haven't seen it done with the 12".

Thanks
Brad

First build Alpair12p Mar-Ken Golden Ratio, Newbie Questions

$
0
0
I've been reading this site for years, this is my first post:)
The foam on my AER drivers in Oris Horn has disintegrated and not in a rush to refoam, I decided to build the Mark Audio golden ratio speakers with Alpairs 12p. I have the drivers playing in their boxes at low volume and am impressed with the sound already. I will drive them with a 300B 6SN7 DIY mono blocks. Pardon my ignorance, I have some questions for build: I have 1/2 wool felt for lining the insides, does the vertical baffle need to be lined up with felt as well? Should i use the rubber gasket that came with the drivers or mount directly to birch ply? And what wire do people use for internal wiring?
Thanks a lot for your input!

4x Pure Audio Project 15" Neo woofers

$
0
0
I have 4x PAP 15" Neo woofers for sale. Sparingly used.

$550 + shipping. Shipping via UPS or FedEx CONUS only.

These are the dust cap version which were, a month or two ago, replaced by the phase plug version.

I had them side by side for measurements and can share, the dust cap version is more linear.

Fix Any AmpliVox (USA) Product Questions...

$
0
0
Realized there is absolutely no repair forums for AmpliVox (US) products. Please post questions here regarding the SW610A, S610A, SW910, SW915, SW925, SW805A, S805, or any other AmpliVox products. I might be able to help.

Optimal gain distribution

$
0
0
I am planning a conventional push-pull tube amplifier with 807 output tubes. I intend to linearize the output by applying feedback from the secondary to the cathodes of the output tube, and an UL tap 33% from the anode.
The first stage will be probably a pentode (E83F or E180F) and I would apply global negative feedback from the output to its cathode.
The phase splitter is a dual triode long tailed pair, with a current generator in the common cathodes.
What I am thinking about, how shall I distribute the gain between the input stage and the phase splitter stage for minimum distortion. If I keep the gain of the first stage low (by large cathode resistor > local feedback), then it can work at low distortion. But then its output signal will be too low, and the gain of the phase splitter must be increased. In this case the distortion of the second stage would be dominant.
My idea is to adjust the gain of the first and second stage for minimal distortion without GNFB, and apply the GNFB after everything works fine. I am planning some 12 dB GNFB, i.e. the open loop gain will be about 4x the closed loop gain. The open loop input signal would be 500mV for full output power. But the question is how shall I distribute the gain between the first and second stage?

Critique request - Cylindrical stacked "folded" vent design

$
0
0
My goal is to use 3D printed router templates to make reasonably sized cylindrical enclosures from stacked 19mm pieces of MDF, not unlike what's been done for several line-array setups on this forum. I want to to create a model that accommodates different drivers and/or response requirements by varying stack diameter and height.

The bottom half would be a down-firing subwoofer as described below. Top half would be front-firing FR, either sealed or ported, potentially with 'clockable' multiple drivers for dispersion.

The idea started while browsing smallish subwoofers and playing in Basta; I noticed the the port length is quite long. I came up with the following design, and wonder if it will work. The design is a long port folded 5x within the cylindrical shape. The ports will "bend" via plates that connect 2 triangles. These top & bottom "joining" plates are clocked so that the port "flows" clockwise.

Working backwards from these "joining" plates, I calculated the triangular port angle so the area would match as best possible, to try to maintain the same cross-sectional area throughout.

A sample design, based on the Tang Band W3-2088SOF. I envision using similarly routed "rings" for the box itself, down-firing.
-160mm outer diameter
-10mm walls
Here's the Basta 'recommended design'. I believe Port Velocity is OK for chuffing at a max of ~14.22m/s?

Click the image to open in full size.

Here are the 4 "plate" designs required to make this work:

Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.

Here's the example cab design. Solidworks tells me that internal volume (aka port volume) is 2560cm^3, which is pretty close. Obviously the bottom "box" and top "cap" are missing:

Click the image to open in full size.
Click the image to open in full size.
Click the image to open in full size.

Long story short - aside from the labor to actually cut all these pieces, is this an idea worth pursuing?

Wharfedale e50

$
0
0
Hi. I have a pair of Wharfedale E 50's which I've owned for about 10 years. I put them into dry storage in a loft (attic) a couple of years ago and then got them back out yesterday. When I hooked them up to an amp it was immediately obvious that something was wrong with one of the bass units. Its not working at all except for the loudest spikes of bass when it just makes a brief distorted sound. I took the driver out and swapped it with over to eliminate the chance of wiring or capacitors something being to blame but the driver is the same in each cabinet.
When I tap the bad driver it sounds dull and doesn't resonate at all, the 'good' one makes a loud bassy sound with the lightest of touches as you would expect.

Its possible that a repair has been carried out/surround at some stage in these speakers past as there is evidence of glue. However, even though the glue looks tired and brittle and dry, I cant see any sections which look as though they've lifted.

"Spider" seems slightly stiff but the speaker seems to move freely in and out when pushed on. Here are a couple of videos of what im hearing and seeing.

I've just moved house and have been looking forward to setting these up again now I have the space so would love to know if they are 'fixable'!

YouTube

YouTube

YouTube

semi conductors for F6 kit

$
0
0
In addition to the JFETS I assume I also need these to complete the F6 kit?

"4 - IRFP240

4 - 5.1V Zeners"

These are currently on backorder on the DIYstore.

Are there other, external sources for these or should I just wait ?

Confirming I need both the JFETs and these semi conductors ?

thanks

NAD C720BEE (C320BEE) fixed.

$
0
0
Hi.
I am French.
Excuse me if my English is not very good.

I own a NAD C720BEE.
It does not work anymore.
I did not use it for several months.
He was, all the while, in standby mode (amber light).

The breakdown is:
- VACATION SWITCH ON/OFF -> ON => POWER/STANDBY/PROTECTION LED -> AMBER.
- POWER Button -> ON => POWER/STANDBY/PROTECTION LED -> stays AMBER, but i hear, after a few seconds, some clic on some relays.
- The TROUBLESHOOTING GUIDE indicates : CHECK THE 12V POWER SUPPLY CIRCUIT.

I have not +12V, on E-Q413 (J123 (12V)), because i have not +18V.
The +18V is generated from the +37V.

For information, the value of +/- 46V (V+, V-) are +/- 37V. The power supply is, therefore, in degraded mode.

The VFD board is OK.
The Reset (FM + CD) is OK.
The Software version ("FM''+"AM") is V 1.03.

After investigation, R45 (33 Ohms 1/2W) is broken (no +37V on C-Q41)
R45 was broken because C49 is in short circuit.
Becarefull: the schematic indicate : C49 47uF/ 25V, on board it’s a 47uF/50V.


Good luck.

Loubine.
Viewing all 93807 articles
Browse latest View live