The British Museum, How to play an ancient rock gong

"The British Museum invited Dr Cornelia Kleinitz, an archaeologist specialising in rock art, and Liam Williamson, a modern rock drummer, to try and discover how a rock gong might have been played. This was the result.

Rock gongs are a type of lithophone that were used for thousands of years in several parts of Africa. They may have been used as part of rituals, to signal other people, or as a form of expression. Although they look like plain boulders, they have a hollow, metallic sound when struck due to the composition of the rock.

This film was created with the African rock art image project which is supported by the Arcadia Fund."

How to play an ancient rock gong - YouTube

More specifically, kitchen cabinet doors. Ugh, mine look nasty, should have dealt with this more comprehensively years ago. Should probably replace the doors entirely but don't want to deal with either the project or the $$$ at this time.

I've sometimes used wet paper towel, then dried off right away, gets stuff off without doing much damage. However there is other caked on sticky stuff from who knows what my wife is doing, and grease residue, and around the knobs/handles I think finger residue. Yesterday I used those anti-germ wipes, they take a lot off, but checking in an unobtrusive spot also not good for the finish, too harsh.

What are better products to use? In particular, those wipes I think have a good texture to get stuff off, is there a non-bleach version of those? And some kind of stuff (Goo Gone?) that won't kill the finish too badly?

I have an upgraded Audio Innovations Series 500 tube amp. An exuberant nephew bounced a tennis ball off one of the power tubes (an EL34). I examined it - it looked fine but it wasn't. It had a tiny crack. A few minutes into the next playing the valve burnt out (brief bright yellow fire) and this was accompanied by a very significant pop thru the left speaker. The left channel is now silent. Apart from replacing the valves has anyone got any idea what I should look at replacing to get some action out of this silent channel?

Hi, Ihave a Nikko Beta 30 preamp that was working OK now one channel is noisy, has anyone had this problem? any ideas on how to fix it?

Hi, Gang,

I'm digging up an old Dynaco project and am thinking of these replacement transistors. I'm looking for 'yes, good enough' replacements, not making a new, different version of the amp. Comments?

Orginal Replacement
2N4889 2N3906
BF257 2N5551
BC308B BC556
SE6020 BC63916
MPSA20 KSD1616AGTA
TIP31C TIP31C
TIP32C TIP32C
2N5630 MJ15003
2N6030 MJ15004

Thanks,
Cheers,
Frank

I came into possession of a Thorens TD-124 Mk1 in excellent condition a while back (free "long term loan" deal from a cousin). After the usual motor, rubber, bearing, and lube tasks, the next challenge was the headshell for the ESL S-1000 tonearm because it has an older style EMT connection (diamond pattern), which not many headshells include for a reasonable price. I sourced an EMT connector and a blank headshell, and made my own (some filing of the headshell tabs required). As a test, I put the TD-124 into my basement system with a new AT-95C, and it worked! It sounds better than expected considering there's been no alignment, no leveling, no care taken for the setup, and no break in for the cart. So far I'm encouraged! It's such a nicely made machine. 🙂

Here it is in action:

Thorens TD-124 EMT Connector Text January 16, 2021 - YouTube

The sale is for what you see in the photos. Asking $5k + Shipping - US Sales Only

The sale is for what you see in the photo.

Audio Precision 2522 with the following options:
IMD option
Wow & Flutter option
Burst option
CCIR Filter
A Weight Filter
Low Pass 20K filter
AUX-0025 Switching Amplifier Filter
APIB to USB Adapter
Load resistor setup for testing amplifiers - 4ohm (800 Watt) / 8ohm (400 Watt)

The software is called AP2700 and can be download from the AP website for free. Online documentation is also available.

The specs are similar to the 2722 if you're looking for more information. The distortion and noise floor is still state of the art even by today's standards. If you aren't familiar with AP test systems, this will outperform many of the newer models.

Complete setups like this and in this condition don't come along often.

Condition is excellent. Self test is almost perfect. One subsystem in the monitoring section is out by something like 0.003v. It doesn't effect the test function which is in two seperate sections. I'm not actually sure that this effects anything, but disclosing to be honest.

Rebuilding old 3-way pair, but really don’t know where to start.

Hello all

I’m am hoping this does not get too long as I do try to keep things short, but it probably will so please forgive me for that.

To start, I have a set of pretty old white van speakers that without going into all the details were fine for me for at the time I got them as due to certain reasons that would be long to go into, I was blowing the drivers in them pretty regularly which kinda worked out at the time as this was well before the internet and the way things work today and so as each one did and I finally had a few extra bucks I would just pop into the RadioShack that was about a mile away which usually had ones that could work in stock and just kept replacing them as I could afford to.

The reason I used them this way has long past and so for probably the past 20 years I have been using them for whatever speakers would continue to work for the rear speakers for the Yamaha driven surround sound system for my TV system.

At any rate, as the casings are plenty good enough for my needs, I thought I would get back to them to see if I could get all new drivers and without going to crazy cost wise hopefully ones that could upgrade the sound quality a bit, but while I understand some of the parts, to the parts to select to use for this, I hardly know enough so I was really hoping some people here might be able to help.

Of these things I think I understand the least is how to select a crossover, but for that I am guessing which speakers I decide to use is going to be relevant (?), and then I am guessing the amp that is going to be driving all this is going to be somewhat relevant to the speaker selection (?).

If that is true the amp is also a fairly old Yamaha HTR-5950 that most of the time I am using in a surround sound mode, but on occasion I like to use it in the six-speaker mode to listen to music as well.

The specs I think would be relevant for it via its owner’s manual are:

Built-in 6-Channel Power Amplifier
Minimum RMS Output Power: (0.7% THD, 1 kHz, 8ohms)
Front: 110 W + 110 W
Center: 110 W
Surround: 110 W + 110 W
Surround back: 110W

Past that for now the other info I think also might be useful for the moment is the inside speaker casing size which inside is 13-3/4” wide, 25-1/2” tall, 10” deep and the thickness of the panels is about ¾” and look to be made of glued pressboard for all of them.

For the round hole sizes for the drivers, they are: 11” for the woofer which even though is 11”, for what I have I in them part number wise is saying is a 12” speaker and is mounted in from the front. The midrange hole is 4” and the PN info on the driver says its 4” and is also mount from the front, and the hole for the tweeter is 3-1/8, although via the drivers PN its calling a 1”. That driver is also mounted through the front.

I think the only other relevant thing might be is that for one of the few nice things I own is a 200 Watt B&W subwoofer for this system, so while I’m not saying I don’t need any low-end out of these, a least they don’t have to get into any kick you in the gut ranges as trust me the B&W unit does that plenty well.

Over all in general I am really hoping not to spend more then $50.00 for any one driver.

So just as I figured I knew this would be long, but I think it has all it might need to get started, and I also know this is asking a lot of people on the post board, but if there is anyone who could help me out with things from this point it would be greatly appreciated.

Thanks

I have an old Millett Hybrid headphone amp pcb I am wanting to put into a small case with a Raspberry Pi3+ (with HAT dac) and a 2.5" HDD. I've been trying to determine what would be the best way to power all of this off of one power supply as I want it to be a self contained unit for my office.

The amp requires 24V/0.75A and I currently am using the Pi/HAT/HDD with a 5V/2A wall wart.

I've used a Tangentsoft TREAD back in the day to regulate the voltage to a Millett with good success and I'm looking for something that is similar in size as I would like this to be as small a footprint as possible. So the HDD will go under the amp pcb and the Pi/DAC will be vertical along one of the chassis sides. leaving one end of the 6" x 9" box open (amp pcb is 4" x 6").

I was thinking a dc/dc wall wart 24V/3-5A into a small linear regulator to get the 24V to the amp and to a buck converter to the 5V to the Pi/HAT/HDD. I'm not much on power supplies that have two completely different voltages so I'm kinda lost here.

On another thread, there was some discussion of Unity horn beamwidth and how that impacts the quality of the sound.

I've spent far too much time thinking about this stuff, so I thought I'd throw together a thread documenting some of the things that I've found.

When I rented the Danley SH50s, I found that they sound a lot like a giant pair of headphones. The experience is very much like listening to headphones - you get a really pinpoint soundstage. Probably more than any speaker I've ever heard.

The pinpoint sound is because the beamwidth of the SH50 is relatively narrow, and the horn controls the beamwidth down to below 500Hz.

The pinpoint nature of the speakers can be a blessing and a curse. For instance, with well recorded music, the definition of the soundstage is wonderful. With poorly recorded music, it can be a bummer that everything sounds like it's mono. This isn't a fault of the loudspeaker, it's a fault of the recording. But let's be realistic; speakers that 'throw' a lot of sound into the sidewalls can create a sense of spaciousness that's artificial, but euphonic.

I hate to say it, but it looks like I need some serious multi-variable help from the community.

I recently built out a new set of speakers (that I'm thrilled about) - and upgraded my phono situation (now a Rega P8 with a Hana ML with my current PC3 and awaiting some PCB's for an Emerald build.) I'm just going in deep and currently looking to charge the Pre/Amp setup in my system. Its great now, but I'm frankly researching to build "my" end-game pre/amp setup - the source components are sounding great - the speakers, killer, just need to fill in the gap in performance.

For starters, the speakers are relatively inefficient (more on that later) clocking in what I estimate to be about 84-86/db. @ 6ohms which makes them needy on paper but I'd be curious to better understand how these two are interrelated. I live in a small space, in what normal listening amounts to essentially "near-field) listening at relatively reasonable if not low SPLs.

I was first intrigued by building a Class A amp to power the speakers, I liked the idea of linearity and the Aleph J would represent a piece of audio history to participate in. After further consideration, the "stock" build doesn't offer too much in the way of wattage (not a con, per se) and the cost of the parts puts it into the realm of considering Schiit's Aegir with a DIY Pre, an existing pre or even a purchased one. Those first 10 watts are pure Class A, with the remainder in some proprietary "class a-like" performance scenario. To put it bluntly, the cost of an Aegir is about on par with the cost of the parts of an Aleph J. with all due respect to the Aleph amps, it's hard not to begin to consider that option,

Further down the rabbit hole, I recall my desire and passion for a tube amp - not usually reserved for lower efficiency systems - but still, a single-ended setup could offer that renowned "holographic" soundstage and maybe even a better performer at the now-obvious low volumes we can enjoy. So, plugged in a Maggie 9300 series restoration i did a few years ago (still the original tubes) which is meant to put out something like nearly 10W @ 8 ohms - ran this with a Sansui 555A from the pre-outputs - and it drove the speakers "just fine" from the 2 of 10 position on the volume pot. Was it perfect? Not at all, I think the low end suffered and the top seemed a touch sharp/grainy. But then again it was the Maggie with OG tubes. More to my point, is that those 10 watts gave me more than I wanted from an SPL perspective, but since I know that SPL isnt all there is to what is asked of an amp, then we continue.

For perspective, on these speakers, I am running a Sansui 555A, in full integrated mode - volume at 2 and it's pretty powerful, maybe could go to 3 if I wanted to rock it. Sansui AU 666, even more so, and the AU5900 - even more so. Yeah, I've got a bunch of Sansui's kicking around.

All of that being said - I've got a few options I'm considering (and I'd like to better understand how power really functions to better judge if I can run one of these tube systems as my main amp.)

1. Just pickup a Schiitt Freya+ with an Aegir and call it a game.

2. an Aleph J build and either a Schiit Freya+ or another DIY pre - maybe something from Elekit

3. Elekit 8600S or 8800 with Lundahl. Awfully tempting, if surprisingly ridden with hiccups for some builders - but based on the reading these are some hard-to-beat amps, for what seems like a reasonable price plus some elbow grease.

4. Prebuilt Tube systems - something like Decware's Zen TorIII Mark IV. This is of course high powered and definitely seems to fit the bill. I'd likely still like a pre-amp so

5. Pre-owned market - definitely would require some patience and shopping around but I get the sense that I could find something that punches well that someone would be passing down/along. Some such examples that came up in my brief query into the matter are things like - Cairn 4808, Musical Fidelity's M6S, Conrad Johnson LP70, and I'm sure there are plenty others I haven't considered.

Of course, the problem with any of this is the inability to test/trial them without committing to buying and/or reselling (yes Schiit, as well as Decware, have trial periods, but I'd rather hone in on something before spending a small wedge of the budget on shipping things to and fro.)

I guess amongst the things that I'm most curious to learn is how to better understand demand in the context of efficiency and amp/speaker synergy. It's often discussed that certain pairings work, or don't, but is there a way of simply and intelligently getting a better sense of the needs? Even some testing equipment that I could acquire to better understand the draw etc.

As you can see I'm a bit deep in the hole here, and surely some wisdom will prevail from the community.

Oh, and there's an obvious question of the budget as subtext - I'd say I was originally int he $2k neighborhood - for total spend at the moment - but after reading a bit I'd be willing to go as high as the Decware price point (3500+) and save a bit for a preamp further down. IN any case, there's a lead time on many of these choices.

Help!

Guys,
do you remember 2015? Well, that was the year when the above mentioned kit was offered as a GB. I always wanted to build this but life intervened and now I am no longer interested.
Actually the box in which the unit was sent was unopened until earlier today - yes, I know, difficult to believe.
Anyway I offer the set (not even unwrapped) as ordered then.
Now for the price - I tried to find out what I originally paid but that info seems to be gone - I think it was over 300,- EUR.
So let's take this a my asking price (papyal+3.5%) and shipping (at cost). If you are interested please let me know.

I have a Zoudio amp, its 4 channel with crossovers and EQ, its Great.

I want to try something new for my next project. I'm thinking a pair of 3 way speakers. Are there any 6 channel amps with DSP built in?

Or should I look into a Minidsp and amplifier with 6 channels.

Any other ideas??

In the Power Supply Section of the new edition of "Art of Electronics" a simple HV regulator using Linear Tech's LT3080. This seems to work nicely:

I saw a link to this - Dior Men's Winter 2021-2022 Collection.

Are the speakers real or CGI?

Dior Men?s Winter 2021-2022 Collection - YouTube

If real, are there any details of them?

Hi, Gang,

Does anyone know how many turns of what gauge wire on what diameter L1 is? All I know is that it's wrapped on a 1 ohm, 5 watt res, and that doesn't tell me much. A photo of L1/R27 should be enough.

Thank you!
Frank

Do these amps take IRF640/9640 or all 640’s ?

I'm starting a new thread to discuss the calculations of SOAs and protection circuits, in regular pushpull class AB designs.

I'm making some calculations but I'm not certain I'm doing this right, so perhaps someone will be able to bring some insights.

First I'd like to make sure I am properly collecting the SOA data from datasheets for use in plotting this curve digitally for comparisons with load lines later.

I think it might be a good tool to use excel to store that data. Such sheets could be posted here for sharing.

At the moment, I am looking at making a graph with collector currents on y axis and the vce on x axis, and although I think I have the y axis right, I'm not sure I'm doing the x axis in the best way, especially if I want to include the load reactance factor.

I also would like to end up with an excel sheet to easily calculate the values of the protection circuit resistors. I would use the leach amp as a model for this. What I am trying to figure out is what are all the parameters to take into account in the calculations for the protection circuit resistors, since there are multiple output devices and there are multiple emitter resistors with protection circuit sensor resistors on each of them, all leading to the protection circuit. This is a little complex and the SOA has to be taken into account for proper protection against shorts but to avoid any adverse effect on the sound. So basically I see the protection circuit action should occur above the clipping point, so the clipping is basically the only source of overload related distortion and not the protection circuit limiting the output power before clipping.

Anyone wants to drop in???

Alpine ERA-G320



powers on , plug up to head unit rca to g320 input but its like it has no input signal come from head unit . head unit has good output signal. what can i check on g320 thank

I like the Amp Camp amp except for its relatively low power.

Would it be possible to increase the Rail voltage to 36V without reworking the entire ouput circuit? I have found Blocked as a plug in power supply. (Edit: since the link is blocked: It is a plug in supply, like a laptop supply rated at 36V and 220 W and a 6.1A max)

The main output fet irfp240 has a Vgs of 20V and this power supply at 1/2 VCC would be 18V. Am I cutting this too close? Your thoughts please.

I need to set up my active crossover to match the passive this speaker was designed for. Can anyone tell me how I could start ???

What are my crossover points and such ?

drivers are the
Peerless 830874
SEAS Prestige 27TBFC/G

woofer is 8 ohms, tweeter is 6 ohms

CARDINAL-TBFC-XOVER — ImgBB

One pair of superb speakers designed from Scott Lindgren.I ask Scott for some truly good plans for this drivets and the results are superb.They are build from mdf.They mesure 180cm high,30cm width and 45cm deep.They sounds superb with some verry good bass that you can believe how much bass is there and this is fast and precise.Price is 400euro and pickup only,if someone will buy only 4 drivers the price is 160 euro plus shipping inside EU.

Hi

SB Audience Bianco 12OB150 Open Baffle|Speakerbuddies Lautsprechershop Hifi Stereo und Heimkino

I searched and found some info about this relatively new driver, but not a thorough review.
I would like to use it as a mid bass naked from 150 to 900 HZ.
This driver is reasonably priced here in Germany, but what are the compromises? It has a stamped Basket, is that a problem using the driver nude?
I read that the basket rings, but is that notable with music playing? Could I damp it with modelling clay or something like that? Does it make noises?
Has anybody already gained some experience with that driver?
Thanks for help.

I ordered a chassis through the DIYaudio Store in December and you can imagine my confusion when I got a cryptic message from my wife saying that fedex had left the pallet of "my stuff" in the garage. I discovered this when I got home ...



I contacted Gianluca who stated that there had been a mishap with shipping and my single chassis was delivered to Germany while the German delivery was sitting in my garage. Unfortunately for Gianluca, shipping it back to Italy was too costly and in an attempt to help him recoup some of his losses , I have offered to try and sell the parts here in the USA. I am listing these items at a discounted rate but factoring in that shipping will not be cheap for some of the heavier items. I am located in Milwaukee Wisconsin, so anyone local or willing to take a short drive, could save a little more on shipping. I will not be making any money out of this sad fiasco, all funds gained less shipping will be transferred to Gianluca/modushop.


1. 2 x Slim Line 02/280 10mm BLACK front panel - 3mm aluminium covers

Retail : $108 on hold for @chromenuts

2. Slim Line 02/350 10mm BLACK front panel - 3mm aluminium covers

Retail : $120 on hold for @chromenuts

3. 2 x Slim Line 03/280 3U 4mm BLACK

Retail : $68 on hold for @chromenuts

4. Galaxy Maggiorato GX288 230 x 280 mm Black

Retail : $33 on hold for @chromenuts

5. Galaxy Maggiorato GX183 124 x 230 mm BLACK

Retail : $28 on hold for @chromenuts

6. Galaxy Maggiorato 3U GX388 330 x 280 mm BLACK
https://modushop.biz/site/index.php?route=product/product&product_id=645

Retail : $60 on hold for @chromenuts

7. GALAXY 2U - 1GX288 - panel 3mm
https://www.modushop.pl/obudowa-galaxy-2u-1gx288-panel-3mm-srebrny.html

Retail : $34 on hold for @chromenuts

8. Galaxy Maggiorato GX288 230 x 280 mm 10mm front panel BLACK

Retail : $60 on hold for @chromenuts

Heatsinks
2U x 300 :

Retail : $25 on hold for @s610adam

2U x 400 : for the set

Retail : $40 on hold for @s610adam

Baseplates
Inner baseplate for the Slim Line 280/350 series :
Base per Mini Dissipante 33-400 :

Retail : $10ea on hold for @chromenuts

I have not calculated what shipping costs would be and part of this depends on whether people want multiples.

I think it reasonable to take 25% discount off the list price and then we can figure out shipping costs - I will do this as cheaply as possible.

Do not PM me, post on this thread indicating interest in an item and then we can take it to PM for details. First response reserves first option, unfortunately CONUS only ( limited to US shipping )

I do have a full time job that limits my ability to monitor the thread but i will check in and respond to people.

** there are 2 larger ( and heavier ) chassis that there is possible local interest for , if this does not work out, I will list them here too.

thanks.
..dB

FS: Woofers Seas E0045-08S W22NY001

Hi, I sell the speakers seas w22ny001 they have about 6 hours of test so they are new, the price would be 350 € + paypal commission + shipping

The price is for the 2 woofers the pair.

I’m just now looking into streaming. Haven’t done anything yet. But I keep reading about gap vs. gapless playback and I don’t see where it’s that big of a deal if there is a few seconds of pause between tracks.

When listening to a symphony there is almost always a pause between movements. I’ve been to live concerts where the pause is even longer than a few seconds. Sometimes five to ten seconds. Depends on what the conductor wants. And it’s a good thing.

So why is such a big deal being made out of this for home playback? I don’t get it.

Hello,

this might look like a stupid question since all of us know that a resistor is placed in front of the capacitor or after ist when using an L-pad. Nothing spectacular. I just saw the schematic of rather expansive 2-way kit and there is an electrical third order highpass. Before the first cap there is a resistor and right after the tweeter another resistor. They state that this way the tweeter is decoupled from the amplifier ground. Can someone please explain this. If this is correct, would it be a good idea to split the resistor value in two halves and place them in the above mentioned way? Any explanation is highly appreciated. Thank you!

Is there a possibility of adding RSS Syndication to diyAudio? It would be nice to have a feed of recent posts in my email inbox instead of having to have my browser open to this site. I am pretty sure vBulletin has this feature built in.

-D

Hello.
I need user manual (if service manual available much better) for Jungson AV-899C (AV-MC580DK).

I do already have the JA-88D schema and the JA99 as well, but I need the user manual for this AV-899C to try to rester to factory default and lñater configure it.

Thank you

hi,
i would know if you tried both of these tw.

who sounds warmer between the two?

any opinion are welcome.

thanks

regards

I'm looking for a Cambridge Audio Azur 540C (1st version) service manual to help me perform some mods. Do you have it or do you know where it's available for download? Thanks!

Just going over some studies and pages related to hearing, and loss with age.

The average middle age and up individual cannot hear past 14khz.

Further, the sensitivity above 2khz begins to drop off with a slope of around 18db/oct and once you reach your 60's, a frequency of 4khz would need to be almost 20db louder compared to 250hz to sound the same as when you heard that tune in your twenties.

Holy crap.

And if you smoke or have high blood sugar it's worse... a smoker with the diabeetus who is exposed to over 85db on a regular basis would likely really love an uncompensated dipole.

"Due to the impact of continued exposure to loud noise over time, usually the younger we are, the better we hear. The ‘normal’ hearing frequency range of a healthy young person is about 20 to 20,000Hz. Though a ‘normal’ audible range for loudness is from 0 to 180dB, anything over 85dB is considered damaging, so we should try not to go there.

As we age, it’s the upper frequencies we lose first. So by the time we hit middle-age, we can expect to hear up to around 14,000Hz. Age related hearing loss (or presbycusis) naturally develops as we age and our hearing can begin to deteriorate as a result of external factors, including the environment and existing medical conditions."

"Sounds with frequencies above the realms of human ears are called ultrasound and those below are called infrasound. Though we’re capable of distinguishing between 1400-odd pitches, most of the important speech-related sounds fall within a narrow, relatively low spectrum.

The highest note of human speech is a soprano singer’s C7 (around 2048Hz) and the lowest note is the C2 of a bass singer (around 64Hz). Though we can’t scream much above 3000Hz, US singer Tim Storms has sung a note at 0.189Hz. Ironically, no human will ever hear it, although it is possible to feel it."

The above comes from The Normal Hearing Range | Hearing Health Blog | Amplifon

I would like to know what everyone thinks the implications of this are with regard to our beloved hobby, measurements and subjective impressions of different speakers?

International power supply IF15-15 with output can be set to 12v/16amp or 15v/15Amp. It has options for various input voltages 100 to 240.

Its almost un-used, I have connected power cable and tested to make sure its working, haven't touched anything else.

Price is $15 plus shipping. All proceeds goes to diyAudio.com

Dimensions:
Weight - 18 lb, 18 x 10 x 9 inches.

Please calculate shipping from 94538

Hi!

Is there anybody out there that could help me get a copy of the MARANTZ 2285B Owners Manual?
Calling out from nowhere else but the AMAZON jungle.

Thank you.
Bwana CHIUSI, at your service.

This is to observe in general by all devices of the above mentioned models.

At least there must be resolder at solder side of the main board in this aera.
Better solution is the replace of this transistor to a version with TO-126 outline (e. g. BD139) and heatsink (or electrical isolated mounting on chassis).

Who knows the reason for the enhanced power loss in the upper half (positive rail) ?

BTW - The laser unit (optical pickup) is the KSS-210A from Sony.
And the Transistor is Q608 (2SD1858, ROHM-MPT3) by NAD514 and Q102 by NAD 502.

My first post here. Even if I have read the forums extensively before. I am recapping a Pioneer A400.

Originals power supply caps are ELNAs made for Pioneer 10000uF/50V so called Audio grade (ELNA ACH1152 CEW 85deg).
403 Forbidden

Decided to up the storage capacitance while confirming to footprint and diameter.

I wonder between this so called Nichicon Audio series (KG) and a general purpose Cornell Dubilier (CDE) which one would be a better performer. Considering CDE is 22000uF with higher ripple current at half the price
https://www.mouser.sg/ProductDetail/Cornell-Dubilier-CDE/380LX223M050A052/?qs=sGAEpiMZZMvwFf0viD3Y3WPyvz8CmpD%2FW7xQi70ABWA%3D

vs Nichicon

https://www.mouser.sg/ProductDetail/Nichicon/LKG1H153MESCAK/?qs=sGAEpiMZZMvwFf0viD3Y3RXRUVU1xXQDkzt%252ByEd7670%3D

Or even this
https://www.mouser.sg/ProductDetail/Nichicon/LKG1H153MKN/?qs=sGAEpiMZZMvwFf0viD3Y3TGBqvvFdz90LkJq7wjot8pJSpSLoAvoMw%3D%3D

Which among them would be best for in your opinion? Going 22000uF per rail with CDE better that those Nichicon "For Audio" types?

Hello, i recently am able to pick up four 3-way ssh-771 boxes for 50 euro fully working. My question is are they gonna be ok as a theater system placed as surround behind and in front of the couch and, if anyone worked with them, is the enclosure good for a diy swap?

Hello,

I was given a Cambridge audio AZUR 640c. Version 1 I believe.

The tray belt was giving me issues, so I replaced it.

It now has a problem that when playing, after a song or 2, it will pause, attempting to play again, but wont.
Ive replaced the pickup, a KSS 213C, but no difference.

Id be happy to replace capacitors but dont know which ones could be the issue.
One thing I notced is that if I stop the spinning disc with my finger, then spin it with a gentle push, it will play for a few more seconds.

Any suggestions?

Thanks

What are your thoughts on this amp? See attached schematic. It sounds good and rather neutral to me.

I recently came into possession of a Classe 70. Since they're out of business and the schematic is readily available, I'm curious as to what you think of the design, which they apparently used on every amplifier basic form and simply scaled it accordingly

Hey There everyone and greetings from Germany,

first for all if this is the wrong section please set my thread to the right one.

My name is Michael,I am 37 Years old and since 10 years a proud owner of a pair of beautiful Infinity RS 1b Speakers. At the moment the play in a 25 m2 Living room and sounds amazing.
Now my Wife and me plan to buy our first own apartment and my Wife banned me and my Hifi stuff out of the living room. After hours of discussion I won and will get my first own pure music room. So far so good, to close the gap between that what we like to have and what we are able to afford this music room will be quite small depending on the German way to build apartments. I think I will end up in a room with 4x3,5m maybe ab bit more or less.

Now I have the mission impossible to fit these large speakers in this small room. The best way would be to get better fitting speakers but this damn infinity virus wount let me go and I won't let go my dream either.

The last days I read many pages here in this forum and as far as I know now when it comes to put on Dipol in small rooms, room treatment is necessary. Absorbing or diffusing is the way to go. But how exactly? Bass is not that problem in my room I can work with bass traps and or dsp to manage that. More interesting is how to handle the reflections bouncing back from the walls.

On which wall should the speakers be placed? The short one with less space between then but more space behind them? Or better the long one brider but not so deep soundstage Cause the near wall positioning?

Where should absorbers and or diffusers placed behind the RS 1 wings? Should the point of first reflection at the sidewalls be absorbed or diffused?

Guys u see a lot of questions and work comming to me to get my beloved Infinitys.

I thank u all for it time reading this and I hope my English is not that bad 😉.

Best regards Michael

Hi All,

Just a word of caution ...

I recently bought some items on EBAY.

Almost immediately, the seller sent me a mail stating that his daughter had just been diagnosed with Covid-19 and consequently he and the rest of the family were isolating and also getting tested.

Did I want to cancel the sale or postpone him sending.?


I postponed him sending and wished him luck.


However, it did make me think.
How many people are selling on Ebay and other sites who have Covid-19 and are either unaware of it or who just do not say?

I have always sprayed any package with anti-viral on receipt and then left them for 2/4 days before opening.


Just a thought. TAKE CARE!!


.

I've read where running a true balanced (differential) amplifier as such sounds much better than running it single ended (I'm assuming the same amp has both balanced and single ended inputs here).

Why would that be the case? Is it merely the improved SN ratio from being balanced, or is it something circuit related?

A have for sale since i don t have the neurochrome modulus 86 amp anymore.
- 2x Neurochrome Power-86 + 2 x 22v tgiatras 150va trafos.
The power 86 have the stock boom components.

I m in europe.
Accepting offers. Shipping in europe only.

Tks.

MiniDSP 2x4 module
v1.9



New price: 80 USD
Asking price: 50 USD

I switched over to Texas Instruments DSP's.
Almost never used.
Shipping from The Netherlands, costs are for buyer.

This receiver plays well for about 5 minutes then the right channel develops static and cuts out. Then the static begins to affect the left channel as well.
All lighting remain steady, as well as the current drain.
All the controls have been cleaned, Deoxed and tested.
The power supply has been re-capped (new electrolytics) and every transistor/fet was tested out of circuit, then re-installed, applying fresh thermal compound as needed.
The main amplifier has been completely restored, including brand new output transistors.
I've narrowed the search a bit by removing the main amp and used the preamp out to another receiver to monitor the situation. Hence, the main amp is not in question.
I've checked all the wiring, interconnects and the pc boards were examined under an inspection scope for bad solder joints, open or shorts, but found nothing out of order.
I suspect the problem lies within the P800 power supply board, but I can't be certain.
Nothing gets unusually warm and I've applied freeze spray and a heat gun all around the board to no effect.
This board is a bear to remove, but if I have to, I may be forced to shotgun all the transistors in hopes that will cure the issue.
But before doing anything rash, I'd appreciate any help to pinpoint the source of the problem.
Again, this is the 2330B - Much different from a 2330.

I have a Krell KAV500 with a slight hum when connected to grounded plug but totally silent when connected to a ungrounded one. I know a cheater plug could be used but I want to try and fix problem if possible since I plan on selling and dont want any problems. Anyone run into this issue with this amp? I have changed out the rca cables also and if you use a bad one you get a loud noticable hum in channel a bad one is used in.

Hi, i am selling here my transformer.
This was purchased from Badel Elektronik some years ago.


It it is on for 230V. It hat 4 x 19V wit 10Amps ~760Watt.

This was planned for a Pass F5/Aleph J power amp. But the project has taken a different direction, so I can no longer use this transformer.

If you have any questions please contact me.

I am asking for

110 Euro

Hi

I am building a dual 12 volt power supply. I am unsure what voltage led is required. I was hoping to replace it with a IN4007 but I realise they do different things.



thanks for any help

Dear diyAudio forum,

I'm reading about the Martion Orgon bass and trying to figure out what it is. In an interview the founder says he took inspiration from the bass section of the Klipschorn. Looking at the drawing he provides on his website his design is more simplified, which I think is interesting. He also uses an 18" driver instead of a 15".

The drawing doesn't reveal much.

What do you think the Basshorn actually consists of?

And... what is the purpose of it in this design?

I have attached the Martion drawing, a view of the Martion bass cabinet, and the Klipschorn drawings he based the design on.


Thank you,
Simon

I found a Yamaha CA1000 in the garbage next door. It was dead. All cards were removed, cleaned and resoldered. Few components were changed. It is working now but there are two issues.

1. The input section doesn't work properly, with its three separated ones. Sometimes there is a hum, sometimes not, I try different sources. So I use tape inputs, which work very well.

2. On the left channel there is a noise like a light wind.

hello~
i want to buy 1 or 2 set of Subbu DAC.
better w/ JG buffer.
i live in Taiwan.

thx~

Hi

I'm looking for a pair of EL34 pcb's and a pair of PSU pcb's

EL34 boards are marked as "advice engineering 2017"
PSU boards are marked August 2, 2019

Cheers

Hi everyone.

I 've built a "bulb" tester with a tangsten halogen tube lamp (R7S). According to an electrician friend halogen lamps are similar to incandescent lamps and much easier to find.
Is that correct, do they work and do they offer similar protection if you use them in a simple bulb tester circuit?

Another issues is that, I 've used a 500W lamp for this first built and whenever I plug amps (even a large guitar amp) and other audio devices, just for testing the "tester", there is no glow or dimming and the devices work normally.
But when I plug something much more power consuming, like a radiator (1800W) then the bulb glows instantly and the radiator hardly powers up.

So am I right to assume that the bulb is too big for the lower current audio devices (60W guitar tube amp, solid state audio and guitar amps etc.) to function properly in series?
What the correct wattage would be for 230V outlet?
50W -100W like the incandescent ones or even less?

Thanks in advance

I build the Leak TL/50 from scratch, point to point, following the schematic. Some of the voltages are a bit
high: EF86 165 (should be 150); 12ax7 315v (should be 300) Kt88 plates 478- cathode to plate voltage 425v.
across cathode 45v ;resistor ohms 493. The treble is wonderful but the bass is weak, very weak. I upgrade the coupling cap from .25 to .47uf, along with the screen grid cap on 12ax7. But still very little bass. Now I am a
novice. the only tool I have is a multimeter. Please, no complex theory. Any help to improve the bass will be appreciated. schematic link:http://www.44bx.com/leak/Leak/Circuits/tl50_ecc83.JPG

Hello,
I know that amplifier will give more power to lower impedance speaker, but it can damage the amplifier if impedance is lower than what amplifier is rated for.
And I know that is cheaper to get 4 ohm 1000w amp than 8 ohm 1000w amp.
So what would be the cons of amplifier with 1000w output at 8 ohm and 8 ohm speaker over amp with 1000w output at 4 ohm and 4 ohm speaker?

I understand that 4 ohm systems are used in cars because there is 14.4v voltage limit if not using smps to make voltage higher.
But why are 8-16ohm systems widely used in households?

hi ,

Can any one tell me what is the problem in this circuit. I tried connecting the circuit based on this diagram.I tried making this circuit but its not glowing I did exactly same connections in the picture down but its not lighting . I also used a transformer but still nothing. Do you think the connections of the vacuum is right in the pic. When I connect pin 6 to 1.2V there is a current flows

Hello,

I have been working on this crossover for a bit.

How does it look?

Any changes you would make or suggestions?

Images,

Crossover

Measurement, no gating, 1/6 smoothing, 2db scale at 30"

Measurement, 5ms gating, 1/24 smoothing, 2db scale at 30"

Thank you,

David.

I got fairly lucky tonight and saved two goodmans axiom 401 from the recycling bin. One has the surround that needs to be reglued to the frame but for the rest, they seem fine. DC resistance is 6.9r for both.

However, I cannot find any specifications for these drivers. Would anyone have some ideas on how to use them ?

Power up but no output ..getting rail voltage ..I dont know where to start looking.

Spindle to pivot 247.4 mm
Overhang 15.6 mm
Offset angle 20.8 degrees

Hello, group!
Thanks for being here, I have found so much help on this site and decided to finally become a member.
I am new to valve amplifiers and have been playing around with the readily available Jan 6418 tube. I really dont know what I am doing so sorry for any dumb questions.
I have recently made some amps for my crystal radio receivers (using high z phones) which have worked great, however, when I plug my guitar in, the sound is very weak and distorted.
Another problem is that 3 of these tubes in tandem with a matching transformer can barely drive a speaker. I know that I must be doing something wrong because others have had better results. the schematic i used will be attached, i simply run a few one after the other.
I am running 1.45 v on the filaments and 30v on the plates.
Do I need to run a voltage amplifier tube before the 6418? Do I need to run a bigger power amplifier tube after? Also, can I squeeze a little more out of the 6418, by say, running the heaters at 1.5v and the plate at 36v?
Thanks in advance..

FS: NEW Saburo full range backloaded horn custom-made cabinet

Selling a project speaker that I intended to use as a center channel in a home theater setup. Custom made Saburo design professionally fabricated from 3/4" high density baltic birch ply. Wired with a quality Cardas speaker binding post. Faceplate machined to accept Fostex FE-126En driver.

Specs:
71x18x7 75lbs

Paid $650. Reduced to $275


Due to weight I prefer local pickup in DFW but willing to meet within a hundred mile radius to connect with buyers in Austin or Houston etc

MarkAudio MAOP5 Gen.1







[BOX]
model😀DBH-B08-ML
type:Back-Loaded Horn with Duct (DDBH=Damp-Duct Bacl-Loaded Horn)







MAOP5 sound at YouTube
YouTube????????-??????(Logicool C270n HD Webcam?PC?TASCAM 102i?SONY ECM-23F3???) - YouTube

I've read through the Akabak thread and not found answers to the 2 problems I'm having with Akabak 3.
First a little background. I'm working on a small surround with 2 round ports. Depending on where I place the ports, I get different tuning, so I thought this would be the perfect test for Akabak, since it should do a better job of predicting. I built the box and took measurements with the ports in various locations, then wanted to use Akabak 3 to simulate. But I have 2 problems. The first, and largest, is that the tuning is way off. Here's the frequency response (yellow is measured, black is Akabak model):
[/URL][/IMG]
But here's the impedance:

Nothing I do seems to affect the lower humps or the tuning. I've measured the driver on Klippel and am using the data (tried both the "Klippel" setting and by curve-fitting within VACS).
After a couple days banging my head against a wall, I started fresh with a different box and driver that I had data on. I modeled in SolidWorks, meshed in gmesh and used Akabak. Same problem. The tuning is off by 8Hz and moving the port has no effect in the model, even though it does in real life. Shouldn't a BEM model be able to do a better job of predicting tuning than WinISD?
The second problem is minor, but also frustrating. The voice coil excursion is always zero. I even opened all the examples and I get zero excursion in all of them. Is this feature just broke? It worked in ABEC.
Thanks.

Is a BNC to BNC cable built with RG- 316 cable sufficient for connecting instruments from breakout box / patch panel. run's would be from 6" to 3'.

Instruments meaning O-scope, auto-ranger, DMM etc.

Hi,

I am trying to replace a LM13600AN dual transconductance amplifier with linearizing diodes and buffers and have been told it is no longer made. I did find a similar part a NE5517ANGOS-ND and was wondering if those in the know could tell me if I could use it to replace the 13600.

The LM13600AN is in the Jackplane(input board) in a QSC USA 400 power amplifier. Any help would be appreciated.

My Audio Horizons 2.3svb tube preamp volume control rotates from 7 o'clock (off) to 5 o'clock (max loud) - about 270 degrees of rotation. With only one source (my DAC), the volume gets too loud (around 95db) at 9 o'clock. In other words, it's too loud with rotating the volume control only 20-30% of its range.

Any suggestions for allowing allowing the volume to be more gradual? What should be soldered to what? Thx!

Can anyone tell me the belt sizes I need for the cd tray mechanism?

I believe this is the CDM1. There are 4 belts. Not sure of their precise descriptions. A copy of a service manual might help me.

The player has been in storage for a while and the belts are all slack and need to be replaced. But as they are now stretched I do not know the original sizes.

Or can anyone point me to a supplier who can supply the correct parts, preferably in the UK or France.

Thanks.

This is my first ever post, so a big hello to everyone at diyAdio.com.

I have a problem with my Marantz CD94 Mk2. When I put a disc into the tray and press open/close, the disc slides in as normal, however after a few seconds an 'error' message appears and the tray ejects. This happened a few times over the past month, but is now happening ten-twenty times before finally playing. Can anyone help?

Thanks very much

Mick

Hello all.
Can anyone help me? In explaining step by step how I'd go about replacing myself all four belts ( which I have ready to swap) in my NOS/NIB Marantz cd94.
I do have the service manual but am inexperience with such and so its all rather double dutch to me!
I would however like to be able to do such 'surgery' myself but would need a rather step by step approach....first remove THIS screw then this one .. only then.... etc etc.
I expect this may be a bit of work for someone so if anyone wantsto private message me maybe we could work out if neccessary some appropriate fee I would pay to enable me to replace the belts both correctly and without scratching /marking what is an unused and therefore mint example of this classic 80's player. (this being one reason I'm nervous to hand it over to an outside tech!)
Thank you in advance Philip.

My pass F6 has been playing for years. Just built sp14 tube preamp and when hooked to the F6 buzz and smoke from back right corner. Had this same problem with the NAD steamer preamp. It works well with my phone dragonfly red and nodi 2

I have two Peavey CS800 amplifier amps that someone dropped off and never called or came back for. Ten years later, during the pandemic, I now have the time to take a look at them.
These are beasts. I estimate they weigh ~ 65 pounds most of which is a 6x6x7" E-core power transformer, however, they are well built, use quality components, and are easy to service. The size and weight are quite objectionable of course but they are powerful using a +/-80V bipolar power supply.
I'll check the huge filter caps for leakage an reform if possible. I'll remove the crowbar protector. I may replace the few op-amps with modern types. Initially I'll borrow parts from one to repair the other and, if I like the way it sounds, perhaps I'll purchase parts to repair the other.
I'm thinking of buying one of these bipolar switching power supplies that can be had for under $50.00 on ebay to replace the tranformer/rectifier. This would knock off the majority of the weight.
Have any of you tried this?
Also, is PTC protection device a good sub for the triac crowbar circuit?

What ready made Chassies du you use for your FirstWatt amp?

I am planning a build on an M2x amp and Ive been checking on some chassies:
Dissipante 4U 400mm frontale 10mm NERO coperchi e retro in alluminio 3mm

4015 Full Aluminum amplifier Enclosure/AMP case/ Preamp box/ PSU chassis | eBay

WF1185 Aluminum Enclosure Class A HIFI Amplifier Chassis Preamp Case/Amp Big Box | eBay

WA129 Aluminum Power Amplifier Chassis Class A AMP Case DIY Luxury Shell Housing | eBay

What chassies are you using?
Links and pictures......

Hi,


I've got a bass amplifier that has a fairly loud buzzing sound. I currently live in a fairly old house where there weren't earth in every socket so I thought the buzzing came from the lack of grounding. I installed ground wires to all the sockets and the buzzing sort of stopped or at least reduced.


A couple of weeks ago I noticed the buzzing to be louder again and I also noticed that if I put my hand on the amplifier the buzzing ceased or at least reduced. After some fiddling I also noticed that if I bend the ac cord into a loop the buzzing got reduced too. I thought this is because of a bad ac cable so I replaced the ac cable with another one.


The buzzing didn't stop but I noticed that if I maintain a certain size of loop on the ac cable the buzz cease to exist.

So the problem is actually solved but I'd like to know why is this happening and if there is more elegant solution to it then looping the cable?
Thanks!

I am looking for the schematics for a Soundstream Reference 604.

I was given this amp but it appears that the feb driver board
for one channel is burnt up.

The resistors for the output transistors on that channel are also burnt.

Any help would be great!

Thanks

I found a pair of RCA 40-5003 speakers in a thrift store. These are “big brothers” to the well known Minimus 7, I think they were also known as the PRO-X55AV. I’m not sure if they’re the same as the Minimum 77. From the research I could do in the thrift store, they have a 5 ¼ inch woofer in a vented enclosure and use the same tweeter as the Minimus 7 so I assumed I could use the Zilch crossover with them. The cabinets had a few marks but weren’t too bad, and peering into the grille it looked like the foam surrounds were intact (more on that later). They were asking $10, with my senior discount they were $8.50 out the door - not too bad! We were moving into a new house, I thought these would make a decent garage setup. If not, there was little downside.

Fast forward a few months, we’re moved in and gotten 90% set up so I pulled the speakers out to see what I was dealing with. First I decided to give them a test with a signal generator to see what the response looked like. I drove them to a pretty decent level at 1 kHz and started going downwards. When I was at something like 60 Hz they started rattling and I noticed some dust flying by the corner of my eye. Uh oh.. a quick glance at the surrounds confirmed they were toast. Oh well, I guess appearances can be deceiving, time to refoam.
I ordered a Simply Speakers FSK-5L foam kit, it required cutting away some of the outer portion of the surround but was otherwise a perfect fit. I cut & glued with all the enthusiasm and skill of a second grader, but after allowing the glue to set up for a day the woofers sounded much better. Luckily you can’t see them behind the metal grille!

Once this was fixed I could see that the speaker rolled off pretty sharply at 70 Hz, by 40 or 50 Hz there wasn’t much output. That seemed acceptable for a garage system. Listening to the speakers, they were OK, kind of sizzly on the high end and not much detail.


On to the crossovers. I ordered the parts for the Zilch 2.2 from Parts Express.

Just like the M7, these had a 0.4 mH in series with the woofer and a 2.2 uF bipolar electrolytic and 0.4 mH in the tweeter circuit. I had planned on removing the stock input terminals and building the crossover on a blank copper clad board with banana jacks on the back. Unfortunately closer examination of the back panel of the enclosure showed that there were a number of posts there – mostly unused – that prevented simply mounting the copper clad flat on the rear of the enclosure.

You could cut out the PCB to accommodate the posts but that was more work than I was willing to do. I decided to see if I could modify the stock crossover PCB so I could keep the stock terminals. That turned out to be easy to do.



First the woofer circuit, the 0.8 mH stock inductor comes out and is replaced by Parts Express #257-550. The new inductor is much bigger, but it does fit. You can route the wires pretty easily but you have to enlarge the holes with a drill or hobby knife to fit the lead. This removes most of the pad’s annular ring so you have to scrape away some of the solder mask to allow for a secure solder joint. Luckily the removal of the stock inductor leaves a hole in the PCB that allows for a cable tie to hold down the inductor. Some hot melt glue on the inductor flanges further secure it.

There wasn’t room for the Zobel resistor #015-3 and capacitor #027-422 on the crossover PCB so I simply hot glued them to the woofer’s magnet structure and soldered the leads directly to the woofer terminals.

The tweeter was also pretty simple, the stock 0.4 mH inductor remains in place and the 2.2 uF electrolytic is replaced by a 2 uF film cap #027-414. The 1.8 ohm #015-18/47 ohm #016-47 divider (PE didn’t have Zilch’s 2 ohm value) is implemented by standing them up with the 1.8 ohm connected to the input and the other end of the 47 ohm resistor then wrapped around the PCB to a ground connection. The junction of the resistors is then soldered to the 2 uF cap, and all three components are hot glued together to prevent movement.

The modded crossover fits in place with no problem, and re-assembly proceeds without difficulty.


Now to the best part, listening. I set them on the only stands I had handy which were a bit short at 24 inches high. The difference was amazing! Set about 8 feet apart, and 12 feet from the listening chair, the image popped into place very nicely. Vocals were also very smooth. You wouldn’t call the bass extended by any means, but up to levels that made conversation hard it gave a good account of itself. If you really turn it up, you can hear port noise so there are limits.

As my son would write TL;DR the Zilch mods are pretty easy and make a big difference. I’m going to pair these with a Lepai amp and drive them with an Echo in the new garage, this should rock!

Maplin lateral mosfet pcb's.
I took the original Maplin circuit and added extra decoupling to front end.
Added DC offset trimmer.
Removed inductor (this can be added external to pcb if required.)
£6.99 each plus £2.40 p+p to UK. Paypal please.