I'm the second owner of a pair of Emerald Physics CS2 speakers for a about two years now. I have enjoyed them for the most part, despite some issues with the Behringer Ultra Drive Pro DCX2496 that they came with. The DCX2496 had some of the mods which can have been discussed in various forums, but the audio in the unit decided to completely die after the power to our house was suddenly cut due to utility work in our neighborhood. (At least, that's my best guess as to the cause.) I eventually invested in a miniDSP 2x4 HD and came up with my own EQ settings based on learning a lot about speaker and room measurements. I drive the CS2s with two XTZ EDGE A2-300 Class D amps, each in stereo configuration.

Now to my call for advice -- I've listened to these CS2s long enough that my engineer/DIY nature is starting to wonder if there are ways I can improve the overall sound experience. (I've already been experimenting with room treatment, so we don't need to go down that road at the moment.) With certain music selections I feel like there's a touch of harshness which I don't enjoy. I've found a few random posts online from back when these speakers were fresh on the scene, including some threads about "CS2 Clones". There's also a list of CS2 mods published by Ric Schultz which I came across.

I would like to retain the overall look and construction of the CS2 if possible. Otherwise, I would just start my own OB build from scratch. I'm thinking about the layer damping material on the back of the waveguide and perhaps felt on the front edge as Ric describes on his mod page. Changing out the original Selenium D220TI compression drivers seems like a tempting variable to play with. I'll have to be honest, however, that I know very little at this point about the interaction between specific compression drivers and various waveguide designs. I understand that the CS2 waveguide was relatively cheap and has its flaws, but is reasonable to explore the possibility of retaining this waveguide with added layer damping and find a swap-in compression driver with same 1" throat and threads for mounting? If yes, I'm not really sure where to start for compression driver options. Some of those "CS2 clone" threads are already 15 years old or so... I would imagine that the compression driver landscape has changed somewhat since then. (Some of the models that were discussed, for example, don't seem to be available any longer.) Also... Perhaps there are better waveguides which would fit in the CS2 baffle as-is or with minor modification?

Any advice if this is a worthwhile pursuit and what to focus on if so?

Thanks!
-Luke

Hi,

I want to put new secondary, means low voltage, windings on an old toroid transformer.
In my first attempt to unwind and re-apply the secondaries, I was faced with many challenges.
This is really difficult to do by hand.
I wonder whether anybody put new secondary windings on a toroid transformer already and what was your experience.

In my mind, a bifilar secondary winding would be perfect, but I don't dare to attempt this because I found it so difficult to just apply a single wire.

I guess everybody knows how toroid transformer winding machines work.
I made up my mind how this machines theory of operation could be applied to hand winding and came up with an idea for a hand tool.
I sketched this in CAD:

The idea is to put the tool on the toroid like illustrated, then put the wire onto the tool by just spinning the tool and thereby reeling the wire from the spool onto the tool, cut the wire once it is enough, and finally to apply the wire from the tool onto the toroid by spinning the tool trough the toroid.

Does anybody know whether such a tool exists and where to buy it?

Any other ideas for tools that may be helpful for hand winding toroids?

I was currently thinking, why are there few subwoofers with a cone made of wood?

Maybe it's for reasons of weight and resistance, or because it's difficult to make a concave cone shape in wood.
But without talking about the problems with making the cone, what would make a wooden cone a good choice for a the subwoofer?

And why not manufacture the wooden cone, in a flat format?

Is this correct ?


(using
Capacitance = 2.2μF
Tweeter Impedance = 6 ohms

Crossover frequency would be approximately 12.12 kHz in this speaker setup.)



(with a 3.3μF capacitor and a 4-ohm tweeter, the crossover frequency would be approximately 12.12 kHz in this speaker setup.)

Can anyone hook me up with schematics for Threshold S550E?
Thanks

About five years ago I bought some SEAS Excel drivers (W12CY001). I put them in a pair of loudspeakers I built for a friend. Recently he informed me that the drivers had developed corrosion on the magnesium cones. I have attached some images of the drivers. One is much worse. The speakers were located in an old and somewhat damp house, but not excessively so. I assume that the protective coating on the magnesium cones was not applied properly.
I contacted SEAS about it and this was the reply:
"Hi John,
We are glad to hear that you are happy with the sound and the speakers.
Unfortunately, there is nothing you can do about the corrosion I’m afraid. We treat the magnesium to make sure that they don’t, but this does not work in warm and humid areas of the world.
It is difficult for us to find a solution for this as the climate here is so different, and it usually takes 3-5 years before the corrosion starts. However, we can assure you that this is purely cosmetic, and has no effect on the sound quality.
Med vennlig hilsen / Kind regards
SEAS Fabrikker AS"
I did reply to this that, if corrosion will occur in damp climates, then the ethical thing to do would be to add a warning on their website about magnesium drivers. I did not receive a reply.
Regards,
John

Buck Boost with TL494, What is the use of the opamp here if it can be done without it?. any of this circuits any good to be built?.
Also a buck BJT version.
- Bruno.

I fell in love with electrostats, so I decided to build one after years of hesitation. Please pardon my rough and rudimentary approach in this initial attempt.

The attached image details the dimensions and basic structure of the speaker. As I am a beginner, a lot of the parts have to be bought for the first time, and they might be inappropriate. It would be amazing to hear your advice regarding my choice of parts.

Parts:

• Aluminum perforated plates: these I would probably order through ebay and cut them to shape
• 1/16" insulation plates: simple plastic of this thickness should do the job
• Mylar: a roll of transparent mylar from tapplastics.com with a thickness of 0.005
• Amp: TPA3116D2 Dual-channel Stereo Digital Audio Power Amplifier Board 2*120W D Class

This type of class d amp using the TPA3116 chip usually reaches 50watts per channel for stereo and 100W per channel for mono if the power supply is powerful enough. I don't think the 60W stereo/120W mono number the seller listed is accurate, as the board seems to be the same design as the generic ones from China. Anyways, I do not mean to drive them with a lot of power, just wanted a cheap amp so I don't suffer too much financially if it were to blow up. (Purchased)

• Step up transformer: IWISTAO 20W Tube Amplifier Output Transformer Pull-Push Z11 Silicon Steel Horizontal Installation

This transformer's direct link can be found via a google search. The ratio it provides seem to be sufficient at the price it is being sold at. The frequency response is also very good, so unless I am missing a major consideration, one of this will be driving my speaker connected in reverse: secondary to the amp and primary to the stators/diaphragm

• DC Bias Supply: I could either get one of those "negative ion generators" off of ebay that claims it can produce 5.5k Volts with an adequately high voltage input, or build one with a tiny transformer and cockcroft walton voltage multiplier circuit covered in eevblog. Though that route seems more dangerous as a transformer is probably capable of supplying lethal current at my target ~ 1.5kV, and I don't know what size transformer I should be looking at either.
• Coating power: probably some generic graphic rubbed on with a cotton ball
• Copper strip: a roll of copper strip to apply the bias voltage to the diaphragm
• Miscellaneous: cables/breadboard/trs/rca connectors etc. probably not important enough to be mentioned
• Cement contact glue: to hold the tension of the mylar with the insulation plastic.

I hope this speaker will be able to make a recognizable enough sound when I finish the assembly. Thank you all for reading.

In trying to piece together the non-included parts for my P3, w/ @Gianluca chassis, I am finding few if any places that seem to have most or all of the items. Performance Audio in Utah seems to have most if not all. I am still struggling a bit with matching up the ID vs OD for the 4 pin DIN cable and a couple of other small items. I thought it might be worth posting the various items that I think will complete the kit to perhaps assist others experiencing "Completion Anxiety" or if anyone sees an error.....

Mogami W2839
Techflex Flexo 1/4"
Neutrik NC4MD
Neutrik NC4FXX
Neutrik Blank Plate

Other than chassis mnt RCAs, which I only see the recessed ones, I don't know what to call the cable cincher.

Hello,

The basic need is for the TV to enable its HDMI ARC audio on its HEAC+ pin with CEC so that volume can be controlled using TV remote.

As I understand, HDMI source supplies +5V to HDMI Sink. The Sink relays this back to the source and let's its presence known. This is through the Hot plug detect pin-19
The Source then seeking more info about Sink READs the Sink EDID EEPROM. The source is then in a position to pass content in a correctly caliberated manner.
I hope my understanding of the HDMI initialization is correct.

Now if we have a SMART TV with HDMI input ports and HDMI ARC port with the HDMI ARC port connected to an HDMI ARC Audio Receiver by an HDMI cable, then
would the SMART TV still be considered as a Sink and the HDMI ARC Receiver as a Source?

Will the HDMI ARC Audio Receiver need to have its own EDID? If yes, how would one generate it?
No video needs to pass to the HDMI ARC Audio receiver only un-compressed stereo audio is of interest.

Any help and clarification on this would be much appriciated.
Thank you!

Dear all,
I have a problem when get a digital signal from the ARC gate on TV. I had provided +5V and get digital signal from pin 14 but it not work.
please help me, i need get a digital signal from the ARC get on TV, thank you very much.

Hi,
I tried to open a thread in the fullrange section, and it does not seem I can do that.
The post was marked pending approval, but since, it just vanished and is not published. I no more have access to the draft either.
Is there something I should do to be able to start a thread?
Thanks!

Hi,

I'm looking for a DIY 4CH DSD128 DAC to use with HQPlayer NAA driving two speakers & two subwoofers?

Fyi, I'm comfortable hand soldering SMT, I've ordered BOMs from DigiKey and PCBs from Chinese fabs, so I'm not a complete newbie.

Thanks
Richard

Hi all, I’m looking for a pair of these JBL 8” x 8” horns. I can’t find them on line. They are PT-D95HF. jbl pro parts # 364700-001

New TS400-4 15" Subwoofer & new Hypex DS 8.0 800 watt plate amp. $200.00 for both; I won't sell them separately. Local Vancouver area pick only. They both go to the landfill within the week because I have to move and got no space.

JH

* I will be unable to sell or ship items between Jan 16, 2024 and sometime in February or March. I am in the middle of a cross country move for work. My partner might be able to fill an order but I can't guarantee a timeline of when she'll be able to. If you were on the fence, please PM me and maybe we can make a deal? *

I have a variety of used and unused drivers (subs, mids, tweeters, full ranges) that I will be adding to this listing over the coming weeks. Anything listed here has been stored either in the temperate basement of my homes or more recently in a climate controlled storage unit. I am trying to price everything for a quick and easy sale.

Offers welcome, combined orders I'll be way more lenient on pricing.


All prices are without shipping, and I will charge actual cost via pirateship. Combined shipping encouraged! I can ship in or out of the USA, but for my own protection shipping outside the US is non-refundable, no returns. Within the US you may return items at your own expense for a full refund (ex-shipping) within 14 days of receipt. Local is St Pete, Florida. Meetups welcome within a reasonable distance. I accept Paypal G&S, or local cash.
For Paypal, please send your paypal to me in a PM and I will invoice you through Paypal's G&S so we both have protection for the transaction.

Apologize for the repost - I added many replies to my previous thread to add items but I cannot mark items sold in edits outside the first post in a thread.
This post is a collection of all items I have left for sale.

Woofers:
$60/pair
Peerless HDS 831735 6" woofer. I think this may have been a speaker buyout - literally my first MWAF purchase back in 2011. As you can see I was more of a driver collector than a speaker builder.
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$20
1x NS270-44 10" low profile subwoofer. I only ever tested this, never used it.
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$30 /pair
2x Peerless 831858 DVC 8" woofers. Unused except testing.
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$50/pair.
2x Dayton DS215-8. One unopened, the other tested extensively. Soldered wire on the terminals.
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$75 for 6
$120 for 12.
12 8" woofers from ApexJr circa 2012. I tested each one and mounted at least one for measurements but never used them.
Shipping is 2 boxes at 40lbs each.
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$20
Dayton NS390-PR passive radiator. Bought at MWAF, never used. Has mounting marks.
https://imgur.com/a/oVVflwy

$50 for all 4. Will not separate.
4x MCM 55-3870 mid/woofer. Tested a fair bit, mounted at least one of them.
https://imgur.com/a/Yb9HOce

$20
1x SB16PFC25-08. Tested, never used.
https://imgur.com/a/MsLeLls

$30
1x SB15NRXC30-8 Tested extensively, mounted, never used.
https://imgur.com/a/N8iIrVU

$30/pair, $50/all
4x Closeout model 930064 8″ Heavy Duty Woofer with Rubber Surround Part # 299-363
Someone used them in this project, I can't find the original specs. I don't think I ever measured them. Better build than goldwoods at this price point.
https://projectgallery.parts-expres.../4-driver-3-way-floor-standing-tower-speaker/
https://imgur.com/a/GwEn1Py

$25
1x DA215-8 Near mint. briefly tested, mounted for test.
https://imgur.com/a/EIOHPxR

Free with $100 purchase, just pay shipping.
Random sample 10" aluminum cone woofer bought from MWAF.
https://imgur.com/a/83d5aF3

Tweeters:
$60 for the pair. SOLD
Bohlender Graebener Neo3W Planar Tweeter with Deep Back Cup
https://imgur.com/a/fnthlbp

$100 pair
2x Usher 9950-20, mint condition. https://usheraudio.com.tw/portfolio-item/9950-20/
https://imgur.com/a/H5mPnAb

$120/pair.
2x Dayton Audio ES25ND-4 Ring dome tweeters in mint, never touched condition.
https://imgur.com/a/jmnhwk1

$80 pair
2x Tang band 25-1742S. Really low Fs for a tweeter, machined faceplate. Don't know if I ever measured these, I can't find the data. Should be as good as any silk dome.
https://imgur.com/a/0Xbfqly

$40/pair
Two Eminence ASD1001. One was tested in a build but not used, other is NIB.
https://imgur.com/a/cAm6TO4
Also in the photo above, two Dayton Audio H07E. $5 for both if you buy the drivers

$75 for the lot.
156 mylar tweeters from apexjr. I must have misplaced the 4 I tested, I originally bought 160. I never took the time to build that line array...
https://imgur.com/a/P5UZQZs

$10 for all 8. SOLD
8x NOS tweeter. 8480027 08354 R 920. I think these were a buyout I grabbed at MWAF for cheap.
I may have a couple loose ones in another box, but I literally just cut the band on this to find out what was in it.
https://imgur.com/a/H0dVJWR

$10
One JBL PT-B99HF-1, JBL part number 364914-001 Horn used in the fEARful and fEARless bass guitar cabinets. I built mine with the H07E since JBL was taking forever to fill my order. The part randomly showed up months later.
https://imgur.com/a/Jl7sXSr

$75 for 3
3x Peerless XT25BG60-04. great tweeter, tested but never used. Basically mint.

$35 for all. SOLD
7x Peerless BC25TG15-04. I have no idea what I was doing with these. Two have modified face plates, All have been mounted and soldered to.
https://imgur.com/a/DwiaO8g

$15 for 3
3x ApexJr silk dome tweeter. I had a fourth but I don't know where it is. Two unused, one used for test.
https://imgur.com/a/cvcdAoD

$15/pair
2x Vifa BC25SC06-04 seemingly unused.
https://imgur.com/a/eZFDOgW

$5
1x Dayton ND25FA-4 Mint in box, never touched.
$10
1x Dayton ND25TA-4 Mint in box, never touched.
https://imgur.com/a/GStB3lr

Mids/Fullrange:

$120 for the pair.
$225 for the 4x lot.
6x w4-1320SJ, 2x from one production lot, 4x from a second lot. All are mint condition, measured for T/S only. Considering these are priced at $120 new... I hope this is a fair deal.
https://imgur.com/a/0zFH1gP

$60 for a pair
2x Dayton RS100P-8. Measured for T/S but unmounted, mint condition. These are very nice drivers imo. Still sold new @$40
https://imgur.com/a/Ggo0I8F

$80 pair SOLD
2x Tang Band 50-1426SA Dome mids in mint condition.
https://imgur.com/a/JdEgrBY

$25 for the lot?
4x TC9FD18-08. At least one was tested a lot, mounted on a plastic plate to mount to my wall baffle. The others look unused.
https://imgur.com/a/xI87bX6

$25
1x RS150p-8. Mint, briefly tested.
https://imgur.com/a/y6tALGw

$50 SOLD
One lonely Morel EM1308.
https://imgur.com/a/xGNmFwG

$50 for 60 drivers.
60x Aurasound AS3-75-16FR 3" drivers from madisound 2012. Some tested, most never removed from the box. Must buy the lot.
https://imgur.com/a/tbpgJgw

Amps:
$120
Behringer A500 Reference 2ch Amp. Used for a few years, been in storage for probably five years with occasional use for testing.
https://imgur.com/a/u8KASkA

$300
Peavey GPS3500 Pro amp.
Absolute unit of a power amp. I've owned this since around 2011 and used it for home theater, bass guitar, and dorking around with speakers. Light use compared to its design capability. Just tested operation into 4Ohm dummy loads on each channel, and 4 ohms bridged (checked voltage with oscilloscope). I can't test to max since over 1800w pops the circuit breaker anyway.
Shipping will suck, so maybe we can split it.
https://imgur.com/a/zwWrAtE

MISC
$25
Rolls MP-13 mic preamp. Missing the wall wart, otherwise mint condition.
https://imgur.com/a/mq9shf0
$200
Yamaha PB-1 Bass preamp. Somewhat rare these days so I'm struggling to find market price. I think $200 is fair. I really don't want to sell this but I'm not using it to its potential.
https://imgur.com/a/lOPK635

1x Peerless 835023 in unknown condition. Free with $100 purchase. Claimed

I have been loving my BIBs with Tang Band W8 2145's in them.
(They were designed with both, the W8 1772s and W8 2145s in mind. The measurements were 99% the same, just the BIB is a few centimeters taller because the Fs is 40Hz on the 1772 and 42Hz on the 2145.)

However I also have framed pictures of Stevie Ray Vaughan, Ronnie James Dio and a few others on the wall, which are currently somewhat obstructed by the BIBs.

So I had a random thought: Why not try to fold the BIBs?
Of course they need corner and ceiling/floor loading, so a folded BIB would be too far from the ceiling, so the more precise question is:
Why not fold an inverted BIB (sideways)?

That way the wall would be unobstructed again and instead I'd have 2 cupboard-like speakers that I could put my plants and bonsais on.

The only catch:
I can formulate my idea and I am able to visualize it in my head. But I fail at trying to draw up a plan, let alone re-calculate the excel sheet's BIB-plan.
(I have thought about folding other speakers, but my mind isn't very creative when it comes to "re-formulating geometrical 3D figures)

Could anyone help me with that or even make a 3D-setch of what I have in mind?

I've added an image that maybe helps convey what I mean more precisely. (Long story short: Make a cut in an inverted BIB and fold the top half down)


Also, if my idea is totally bogus and wouldn't work or have serious problems, please tell me! 😀

@Scottmoose oh, on a sidenote, if I turn up the volume on the baby labs you designed, I can really feel the "bass" not just at the vent, but also in my body. Sure, the office room is a little small and it's not as much of a bass as a "BIB in corner"-bass, but extremely impressive nonetheless. The baby labs work damn well.

I apologize if this has been asked before. I haven't seen anything in reference to it. And I may just have a gross misunderstanding of how this all works. If so, I'm hoping someone can explain it to me. I have seen and heard people give output power numbers for some tube amps that seem...unlikely. Like this, pulled directly from Wikipedia:

"More commonly found is a pair of EL34s running class AB1 in push–pull around 375–450 V plate voltage and producing 50 watts output (if fixed bias is used), while a quad of EL34s running class AB1 in push–pull typically run anywhere from 425 to 500 V plate voltage and produces 100 watts output. This configuration is typically found in guitar amplifiers."

Okay, so... A pair of EL34s running at 450v and 55mA should be dissipating a grand total of about 50 watts, right? And that appears to put them right at the edge of their operating limit unless you up the voltage and drop the current. But that isn't output power. A fair amount of that should be waste heat. Quoting that number as output power would indicate 100% efficiency in the amplifier. Unless tubes break the laws of thermodynamics, that's impossible. Am I missing something? Because if I'm not, saying something like that is misleading at best, and downright dishonest at worst. And Wikipedia isn't the only place that I've seen numbers like that. Other sites and people quote MUCH more reasonable numbers though, so it can be a tad confusing for someone trying to learn.

I have a question beacause I got two contradictory information from two reputable sources.

A dac diyer my friend told me that the I2S standard is always at 32 bit and during the conversion in the dac, the last 8 bits or 16bits are just set to 0.
But I remember that @iancanada once told me that only the GPIO of a Rpi can output true 16 or 24 bit during audio reproduction.
Since the Rpi is I2S standard, is the output forced always to 32 bit? Or no?

I bought 2 tpa3250 2x100w cards from Aliexpress. both did not work. LED did not light up. LM358 integrated reverse assembly. I fixed it. LED gave light. but it still doesn't work.

So I've got an interesting project plan to bounce off the wizards in this group! When looking at improving our church's sound situation, I'm planning to replace our 2 traditional PA speakers with some low profile sound bar style speakers that I can tuck right up against the ceiling because I need the headroom for visibility of the projector screen up front.

Here's my plan: Using the Klipsch R-1650-C 6.5" ceiling speakers, build 4 boxes with 2 speakers in each box (Or 3 or 4 speakers per box if need for volume), and spread them out across the front ceiling... pointing down at the correct angle to cover the whole auditorium. (I can get the speakers for $50 each right now)
We have 2 powered subwoofers on the floor that easily carry the lows, so these are only supposed to run the mids and highs. I'm trying to do this on a low budget... I realize to make this 100% professional audio, there's a million things to consider, but I hope to just kinda cover the basics since we're not talking about super pro audio here... just some pretty good sound.
1. Is this a ridiculous idea or might actually work?
2. My research seems to indicate that a sealed box would be best for this application since I'm not looking for them to push any freq below 100hz. Agreed?
3. What volume/size box should I be shooting for?
Anything else?
Thanks!

I've had this player for a long time, it's been working for more than 10 years and I only use it as a transport for my CD collection. Until now, the basic cleaning of the laser, ie the lens, would bring it back to life, but now I should clean the laser pick-up from the inside as well. Has anyone tried it? Or should I immediately look for a new laser or replace the entire HL-05P loader if it can still be obtained somewhere? Or buy a used BD390 and get a laser pick-up out of it.
The catch is that I modified the power supply on this player and thus got a better digital output compared to the Rotel RCD951, which I also have as another option.

Hi to all, Please can i have your opinion on the said speaker the sound is not that good to my ears. Do you guys think if i recap the crossover will be beneficial or i'm only going to waste my money. Thanks in advance for your help.

Correct model no. is ANM2 - sorry for the misspelling in thread title.....
A long shot, but any help here appreciated thanks 🙂

I am experimenting with a 35T OTA (spud) amp. It's up and running and producing nice, clear music (subjective). I only need about 10-20W for my classical chamber music. So far so good. But, I am concerned the design is not optimized. Here is my concern and your input would be great to confirm/deny my thoughts:

1. My existing OPT is 5K:8ohm which will be replaced with a 14K:8ohm OPT. Rp ~ 8.5K. My theory is that this should help both the bottom end damping and top end extension.

2. Currently, I am using a 1:4 step-up transformer. I am thinking of going 1:8 (as shown in the schematic) to give my voltage drive. But what about current drive? I read somewhere, with little detail, that the 35T needs "current" to drive the tube. Is this only if A2 is being used? I am currently using only A1, from what I can tell (see curves with my operating points).

3. Operating point is 875V, -9V bias, 35mA. Thoughts on this for A1?

4. The 35T is not glowing red / orange as indicated by the user manual. But, I am getting nice music. Is glowing red / orange required and if so, what changes to the operating point should be considered?

I feel as thought this could be a very nice amp with some adjustments. Right now is sounds pretty darn good, but I suspect it could be better. As always, your input is appreciated.

To all past, present and future Aspen members, and all forum members:
MERRY CHRISTMAS AND HAPPY NEW YEAR!
Let us hope that 2024 is a good year despite the negative vibes we see in eastern Europe and the Middle East.
So far Oz has been rain drenched, particularly in Far North Queensland, and even a few bushfires.
One thing never changes; we are all addicted to audio and the virus corrupts most our waking days!!

Oh, to be on the edge.........

Hugh Dean
Aspen

Hello,

Recently bought this TPA3116 board and I wanted to replace the onboard 5pin AUX jack to a regular 3pin jack to route it somewhere else, and during the process of unsoldering the onboard PCB aux jack I broke one of the solder pads, but thought it would be alright since the main L, R, ground pads are intact, connected these pads to my 3pin aux jack and the amp now only produces static noise.

I have no idea how these 5pin jacks work, could somebody explain how do I fix this problem?

I have attached the current and original state for reference of the aux pads.

Have a Denon PMA-880R where the primary of the power transformer is open circuit. The transformer is a potted toroidal. Any way to un-pot these, and probably get access to a thermal fuse or broken wire? Will simply heating the transformer melt the potting material?

Or if there are replacement transformers available?

I've noticed most amp build kits come equipped with carbon composition resistors, you know, the brown base color tubular resistors with hard edged ends. I have two Fender amps from the 60s that use such and not a single resistor in them hasn't drifted 20% high or more in value. I realize the circuits are forgiving and even a 150k in the plate rather than a 100k is going to work, but I just can't bring myself to use carbon comps in a new build.
Do you know something about recent issue carbon comps that I don't know?

I have for sale the F7 clone kit fully built and used for around 100+ hrs in a 5U/400mm case. I have since moved to SIT amp this amp boards are not being used and would like to go to a deserving member. I got this fully matched kit of parts including the PCB boards from one of the forum member. All high quality parts with PRP resistors, matched ALFET transistors, pre-trimmed original bourns trimmers and I got the matched Toshiba jfets from the store. The matching info as the numbered stickers which was sold to me I have retained it on the pcb board for reference. As these PCB boards are not UMS compatible I used wires to mount the transistors. No difference in sound quality and it works well and can be easily used with UMS chassis or pre-drilled mounting hole chassis. I have left the power cables soldered to the PCB and if the buyer wants can desolder the same including the high quality silver plated PTFE input cables. Asking $175 including shipping within CONUS states.

Hello. I would like to create portable speakers from old Heco Reflex 20h (165mm) (I received a housing without speakers from a friend)
speakers for listening on the terrace, while working in the garden or at parties.

I already have a 2x100 Bluetooth amplifier, I also have a more powerful Aiyma 07 if I run out of power. I listen to mature electronic music. I like a clear sound (On the warmer się) , but I don't want the ticking in electronic music to be tiring. I like the sound of the tweeter from the Jamo D025. This will be my first project. Please recommend some speakers at a fairly low price. The housing has room for two speakers and a tweeter.
Case:

• Abmessungen: 500 x 225 x 235 mm (B x H x T)
• Brutto Volumen: 26 Liter

Can we test this board out of mainboard? I tried to supply +5v and -5v and I did not see any waveforms. R31 was open and I have changed it. Also changed TL072 and LM211

Hi all.

I have a pair of Sonus Faber Grand Piano Domus speakers and two of their bass woofers are very bad-looking, as you can see in this picture:



That's the reason I would really like to replace these woofers, but it's very difficult to get the exact same model of them in the market. The original model is this:



As you can see, the woofer's impedance is 8 Ohms, because it works in parallel with the second woofer existing in each speaker.

So I would like to get suggestions of 8 Ohm woofers from other brands to replace these 6,5" woofers. They can be 6,5 or 7-inch and don't have to keep the exact same sonic characteristics of the original woofers. In fact I would be happy if the new woofers could give a more "punchy bass" to the speakers.

Suggestions are very welcome.

Demetrio.

Just purchased a Kenwood VT-181 ac millivolt meter and it is working perfectly.
The only thing which is a little bit annoying me, is the litte offset between the input voltage attenuator scale
and its rotary knob. I want to correct it by taking that knob of the shaft and re-adjust it.
But: how do I take that knob from the potmeter shaft? I first tried to see if I could remove a disk on the knob
to get access to the screw but I failed. What is the way to do it here without damaging the knob?
Looking into the VT-181 manual did not show anything on this matter.

Guys, hello.
I have pair of these speakers.

https://www.roksan.com/en/blog/the-ojan-3-and-3x-is-released/
Originally they had some nice tweeters, but looks like they were damaged and original voice coil was replaces by something else taken from JBL 62 Titanium Laminate.

If anyone can post some info on original tweeters will be very good.

Looking for a pair of 4 ohm TD15S preferably with black phase plugs. I’m in South Carolina. Thanks!

Hi All,

My trusty Nad amp is playing up.

Basically one of two things are happening....The volume is dropping, or/and one channel is cutting out.

Im pretty sure its showing signs of both.

Any idea what the problem might be of if its fixable?

cheers!

I have a Onkyo M-5030 Power Amp and an Onkyo A-809 Integrated Amplifier that I would like to see about possibly getting more detail sound wise.

If I understand things correctly the OPA-2134 has a Higher Input Impedance and output than the NJM4558D hope I'm saying this right.

I don't know where to start to figure out how or what to change component wise on my Circuit Board to accommodate the OPA-2134 if this possible.

Also, the Output Transistors are 2SA1106 & 2SC2581 which are no longer available would be grateful for any advice.

Hello,

This is my second thread in this forum and my first thread was about the EZ80 rectifier. I am thankful to all members who helped us and we now have a working amp. See thread below.

https://www.diyaudio.com/community/threads/help-with-ez80-rectifier.403700/

We (myself and my son) are now building a new amp, an ambitious one, with two speakers. The circuit is attached. The problem is that none of the electronics shops are able to wind a EI output transformer for our specifications, Viz , Center tapped primary rated at 0-200V-0 and 25W and secondary at 0-12V at 25W. We are thinking of using two 8Ohm speakers in parallel (4Ohm in total). In the absence of a output transformer, what alternatives can we use?.

I'm tempted to buy some old tube radios at the weekly flea market and scavenge parts but i'm not sure if they would match specs.

Hi dear diyers. I print 5 PCB of the new UDP3 board (Umbilical Cable Driver for Pearl 3). 1.6mm thick, 2oz superficial copper. I paid them 50 euros in total. This means that the price at which I sell them is 10 euros each. Only shipments to the EU. Contact me privately if you are interested. I kept 2 for myself and friend of mine, I have 3 left.

I own both a McIntosh C-28 preamplifier, and the second preamp which a Pioneer Spec-1 with the additional SG 9500 equalizer to go with it.
Was wondering if anyone has compared the two of these preamps to see which one has the most pure and more robust sound. Please let me know, as I’m trying to figure this out. Thanks

I have great envy to design with the high precision 16bit MDAC LTC1595.
This DAC comes with 2 grades, A, with +/-1LSB max INL or for much cheaper, gradeB +/-2LSB.
I can use the reference input as bi-polar sign bit with adjustable voltage to serve as volume and use only the 15 bits to make the grade B as precise as A.
The only encouraging example I found is the Schiit Audio Yggdrasil
https://www.stereophile.com/content/schiit-audio-yggdrasil-da-processor-measurements
Any DIY exemple?
Any con I should be aware of?

I have ordered a Tractrix 290mm horn, made in plywood.

After a lot of “research”, the HF driver seems to be a good option.
I need the horn to cover the range from about 1Khz and all way up….no super tweeter.

The Tractrix horn has a 2” connection, and I then came to realize that the HF206 is the exact same driver, but includes the adapter.

I managed to find the HF146 at a really good price though, but I then miss the adapter.

Before ordering, I want to ask if the original adapter better than the adapters to be found on the market?
The original looks quite solid, compared to the cheap-looking plastic ones……

This amp is fairly new to me and owning it is a bit of a mixed bag. Something is wrong and I need some advice as to what may be the issue. Or at least some ideas as to what may be at play. The amp, while working, sounds marvelous. Best I have ever owned. Then I'll hear a brief crackling sound and them the amp produces no output from both channels. Turn the amp off then back on again....nothing. Replace the front 2 12AU7's, fire the amp up and off she goes sounding wonderful. Might go a week, lately a couple days then poof, off again. All tubes light up just no sound from either channel. Replace the front 12AU7's and away we go playing fine music. Till I hear that brief crackle.
Arrrgh. I have run 4 sets of 12AU7's through the amp and none stop this from happening.
Other observations.....
After swapping the 12AU7's the longer the amp is off the longer it seems to go between shut offs. Looking for things to try or look for before sending the amp in for a check up. Any ideas?
f1jim

Hi Everyone,

I am trying to learn analog electronics and figured I need to do some 'hands-on' work in addition to the book and lectures. I bought an Adcom 5300 locally for $40 which was listed as not working with both thermal protection lights on. As the lights turn on immediately after plugging the unit it I figured it is an issue with the thermal switch (thermal breaker) since the unit is still cold. I opened it up and checked the 7812 voltage regulator and had good 12v on the output. I started looking at the right channel and measured the voltages on the LM555 chip which seemed reasonable assuming thermal breaker 'open'. The thermal breaker is an Uchiya UP72 85C device and it appears it did not fail "open" but rather had failed as a high value resistor (measured ~14.2kOhm) which effectively forces the transistor Q118 to saturate and turn the output of the LM555 high (thermal LED "on"). I ordered new thermal switches (will take a while) so in the mean-time just put a jumper wire in place and sure enough the thermal LED turned off and I was able to test the R channel is fully operational.
Now, for the left channel I figured I will do exactly the same and sure enough when the unit is in 'stand-by' with 12v coming from the 7812 voltage regulator and all other voltage rails off the LM555 reads 12v on the trigger pin and 'low' on the output and the thermal LED is off. BUT when I turn power on the thermal LED comes on and I have 12v on the trigger pin of the LM555 but the output is high -- actually I'm measuring ~10.8v which doesn't seem right for 'output on'. It is almost as if the voltage is back-feeding from the rest of the circuit. I de-soldered and tested Q010 (2SC1845) next to the thermal LED (it's actually Q019 it's a typo in the schematic) and it tested fine. I also de-soldered an tested Q020 (2SA992) and it also tested fine.

I am having a hard time figuring out how these transistor can back-feed ~10v at the led. Can someone help me out? Thanks a lot!

I found plenty of asymmetrical crossover designs in active crossover world. It’s defined the low-pass and high-pass have different slope rate, e.g., low-pass = 24dB/octave and high-pass = 12dB/octave, and vice versa. First, I thought it might occur coincidentally from the crossover tweaking. However, I rethink and realize that a number of them were constructed by the electronic or active crossovers. Therefore, it could be interpreted that my first understanding was wrong—they should be intentionally created because those crossovers have adjustable frequencies but with fixed asymmetrical slopes, as described above. I’m curious to know what are benefits or purposes of the asymmetrical crossover configuration?

After a few minutes, sound fades to nothing. Clean or gain channels, high or low output makes no difference. A few days later, turn on the amp and get a few minutes of sound again. Speaker and emulated output have no sound/signal, not even hiss. FX loop send has output when the amp works. No visible damage inside. Used contact cleaner to no avail. What could be the problem?

Hello all,

At some time in the not-too-distant future I will be moving to Japan. I plan to bring my Tubelab SSE with me, and plan to continue building tube amps (TSE-II is next).

There is the obvious issue of 100v mains, which can be easily solved by replacing the power transformer (I wish I had originally bought the Hammond 374BX for the SSE, which is universal).

The bigger question for me is how do I ground my amp(s)? Japanese power outlets are two-prong, non-polar, with no ground. According to Japanese electrical standards, devices are supposed to implement their own short circuit protection. However, I have read that it is possible (common) to ground larger appliances.

I do not want to run an ungrounded tube amp in my home. There must be a straightforward grounding solution, as tube amps are quite popular in Japan, AFAIK. Also, is there something I could/should reconfigure or modify in the amp itself to ensure it is safe? Perhaps re-install it all in a non-conductive chassis, with non-conductive controls? Perhaps that is overkill (forgive the pun).

Selling a pair of tannoy kensington se drivers. Raw drivers only but I will provide factory schematics for crossovers. Asking $1700usd.

I'm searching for the most efficient (voltage sensitive) 19mm dome tweeter on the market. It has to be in the low 90s dB/2.83v range and easily reach past 15k off axis to qualify. Its needed for a small nearfield monitor with a very hot midbass.

My initial choice was the beloved Seas 22TAF, but its technically a larger driver with average off axis performance. The 22 TFF is similar and not quite as sensitive. SB makes some smaller units, but they're also not quite as loud.

If anyone has an idea, please let me know.

I have been searching for information on a Heathkit IT-17 tube tester manual.
While searching the internet I came upon this Forum, so I joined. I cannot find the threads that I found during my internet search. Anyone have any ideas where they can be? Thx

Hey,
Total newbie...big surprise😉,
Working on an ancient Sylvania AA5 tube radio. I damaged a socket(very brittle). It's an 8 pin loctal socket for a 50A5 tube.
Having a hard time finding a replacement socket without paying $30 for shipping. I'm wondering if there is an equivalent tube that would fit a regular 8 pin octal socket.
Any ideas would be greatly appreciated.

Thanks,
Betula

Hi everyone, has anyone ever had experience with bnc 18tbw100. What are your thoughts on this speaker. Also does any one knows what guage coil wire is used on it?

Some of the four Focal T120 1” tweeters in each of my pair of VMPS Super Tower IIa/R speakers are showing deterioration in the foam surrounds. There is not yet any apparent deterioration in the sound (at least that my old ears can detect). I have had good luck with diy replacement of the foam surrounds on other speakers but have not yet found a source for the repair materials for these tweeters. The pictures show one of the most damaged tweeters. Any ideas or suggestions greatly appreciated.
Jim Gregory
Sausalito, CA

Hello, for some audiophiles everything can get in the way of faithful audio reproduction.
So my question is: What type of chair interferes least with audio reproduction?

From what I can tell, low-seat chairs tend not to disturb the ears like high-seat chairs.
There are also problems with the backrest materials and chair model that can get in the way.
For example, chairs covered in fabric like velvet tend to absorb sound, while leather chairs reflect sound.
Reclining chairs (armchairs) are widely used for home theaters, but most have a high back.
While club chairs have low backs.

At least for me, the best type of chair is low-seat velvet chairs.
But, I want to know more about how chairs can interfere with audio reproduction.

I have an on-going thread about a second Pioneer A-70 amp. I successfully repaired one, this second one is being a little more challenging.

Kinda stuck here, I think the OP-Amp may be shot - perhaps not...
The problem is the "line-straight" mode. If the Amp is turned on with out being in "line-straight" mode, all seems ok and it comes out of protection. If you push the line-straight button, the amp drops into protection and R23 circled in red cooks off produces a nice stream of smoke. It's a 22Ohm 1/2W resistor.

I have checked the switch and it seems to be in correct working order. It's a two-sided 12 pin switch and I get continuity just where I should depending on the position of the push button. Side 1 is in play and is pictured below as S1-2-2. When line-straight is in the off position the equalizer circuit is turned on which allows for the use of the tone control sliders, loudness and sub-sonic functions. The amp seems to operate correctly in this mode - at least it will produce audio to the speakers and the correct voltages are seen on pins 4 and 8 of the op-amp (-15V and 15V) respectively. Other voltages look correct as well

Here is a cut down representative schematic of the surrounding circuitry:



Q63 is the two channel OP Amp (It's a uPC4558C-P)
So, do you think it's the op-amp or is the problem elsewhere - what is causing R23 to smoke?
Thoughts? Thanks for looking.

I am helping my customer to sell his mint condition LCD5 $2300. included two sets of Audeze LCD 5 cables ( 4 PIN XLR and Single ENDED )
If you are interested I will link you up...He is located in Houston TX

I’ve had this Pioneer SX-780 sitting on my lab floor for about 6 years now and I said that now is the time. It had a failed Darlington power pack when I got it, the STK-0050. The single good pack I donated to a friend to get his 780 going. That pack is still going strong 5 years later.

I’ve seen two options, this Pyramid Audio package, very simple circuit that uses these four pin Darlington outputs, STD03P and STD03N.



The other option is a much bigger circuit, designed by someone that hangs out here and audiokarma I believe, it uses standard off the shelf BJTs.


I don’t have schematics for them, but from what I understand both are fairly well known so I’m hoping people have formed opinions on them.

For the first option, those Darlington devices are no longer available, but I was smart enough to buy a couple dozen of each back when Digikey had them. I have this single Pyramid board in the pic and was planning on etching some of my own to make more. So I have everything needed to go that route.

Same with the second option. A few years back I had about 100 of those green boards made up. I have plenty of the TO220s and TO3P devices as well as everything else. So I wouldn’t need to buy anything for either option, just etch a board for the first option.

Would going from the original Darlington pack to a board that uses Darlingtons be the way to go? I know the second option is probably more widely used. Not sure which offers better performance, but wanted to get opinions of the two hopefully. I’m working on the receiver now, the outputs will be taken care of last.

Thank you,
Dan

The ~35 cm (250 hz or so? ) offset stub at the exit end (and closed end) ?

Audio Grade O-CORE unused only tested.

240V only
2 x 35V @ 150VA
15-0-15v @ 60mA

Included is a Mark Johnson Cap Multiplier, new and unused plus two top quality IXYS rectifiers.

£60 plus shipping

Thinking of importing a Geshelli DAC to the UK for use with my B1 KORG nutube and Amp camp Mini for use with music on my phone and adding a CD player at some stage.
but i am mainly into vinyl. Any advise before i order would be welcome. Thanks.

We have available a number of SR fuses to clear.

Below is a full list of what we have in stock, you can email us to place your order and we will email you an invoice to pay online. david@mcru.co.uk

PURPLE FUSES WERE £190 EACH NOW £150 EACH

ORANGE FUSE WERE £155 EACH NOW £77.50 EACH

BLUE FUSES WERE £130 EACH NOW £65 EACH

RED FUSES WERE £70 EACH NOW £35 EACH

BLACK FUSES WERE £90 EACH NOW £45 EACH

SHIPPING IS £5 UK - £15 EU - £18 USA - £22 ROW - TRACKING CODE WITH ALL ORDERS

My daughter has been getting into vinyl recently, so I've decided to get her a decent-ish turntable (Fluance RT82) and pair of Edifier S2000MKIII speakers. Right now she's destroying her vinyl on a cheap plastic piece of junk turntable from Amazon and migraine inducing soundbar.

The turntable will inconveniently need to be placed on the opposite side of the room as the speakers, so I plan on pairing a WM8782 ADC to an AptX HD I2S input BT transmitter (24bit 48kHz). Not ideal, but it will be infinitely better than what she has now.

Vinyl and turntables are somewhat foreign to me, but I guess the recording levels can be all over the place? I'm kind of lost on how much headroom I need for the ADC to optimize for noise and potential clipping.

The stylus is an Ortofon OM 10 (4mV @ 1kHz 5cm/s) and the preamp I purchased has a gain of 40dB. Right now the WM8782 board is set for 2Vrms full scale, but it can easily be changed. I don't have a clue if that's too little or too much.

Greetings all,

I could use some assistance with the following standard thru-hole VU design. I would like to modify the wattage points at which the LED's activate. What appears to be the variables n this example is at the Zener diodes in most of the LED circuits.

Can someone please tell me how to calculate what value Zener diodes are needed to attain activation at the predetermined wattage? I haven't been to school in 30 years and in all my efforts, in every calculation I try, I am unable to even simulate the circuit below to even get the values shown in this schematic. I am obviously missing something, and it's driving me bonkers.

Example:

LED #7, Zener diode value = 18v in this circuit, the LED activates at 50 watts and above.
- What calculation would I use to determine the Zener diode value needed to have the LED activate at 80 watts and above?

This example is using an 8-ohm speaker connected at points LS. (I am only interested in modifying LED's 5 thru 10, if that helps simplify)

Your assistance is GREATLY appreciated!

I have been looking at a number of soft start boards on Aliexpress, Ebay, etc., and wonder if any of them are any good, if there is a "better" one,

From Connex Electronic, Power Soft Start v3,

https://connexelectronic.com/product/power-soft-start-v3/



Yuan-Jing Soft Start Module (110V / 220V) w/ Thermal Protection, Product Code: FNB-POW-SB-001,

https://www.yuan-jing.com/soft-start-module-110v-220v-w-thermal-protection



Lusya 2000W Amplifier Power Supply Soft Starting Board 100A High-current Relay For class A Audio Amplifier board AC220V or AC110V G1-006

https://www.aliexpress.com/item/32998344730.html




GZLOZONE POWER-S.S Class A power amplifier high current power supply delay soft start DIY Kit 20A 110V/220V optional

https://www.aliexpress.com/item/32813795278.html



Power Supply Soft Start Board For Super Power Amplifier Bingzi Transformer AC110V AC220V

https://www.aliexpress.com/item/1005006389308823.html



Also open to suggestions for Soft Start options.

Anybody know where I can get scrim cloth?

I re-clothed some speaker grills with white fabric. It’s totally see through. I need that scrim cloth backing. Know where I can find it?

This month, December 2023 marks 10 years since work began on the moOde audio player project.

Thanks to everyone for your dedication to moOde and for helping to improve and support this nice Free Open Source Software for the wonderful Raspberry Pi and DIY audio communities.

Consider making a donation to acknowledge a decade's worth of commitment to DIY audio and the enjoyment of music. It's a great way to show your appreciation!

Let's keep the coffee flowing and the project going 🙂

Enjoy the Music!

-Tim

Selling 1x Ortofon SPU #1 S cartridge

New and unused

Asking 450€obo, excl worldwide shipping

Asking $4000

By far the best speakers I have ever heard. I'm not one for a hyperbole when it comes to audio but once I set these up I literally stopped thinking about speakers! That hasn't happened to me since I was 12 years old. They just sit there and let the music come out, flow in a full body beautiful high resolution way.

The speaker cables are quite long and set up with nice connectors

It has the analog signal processor for this three-way version. I labeled everything clearly on the back of the unit to ensure no mix-ups.
At the moment I have three different amplifiers feeding them. Let me know if you have any questions about amplification and I would be happy to talk. The main thing is to have the gain matched.
Only selling to pay towards a car I just bought. Honestly kind of hoping whoever's reading this won't buy them!

Dear Friends,

You must have noted that I can't stop myself to explain stuff in the field of audio design.
That is something inside me, and it needed an outlet.
So I decided to take the plunge and set up a course for people who want to learn to design audio electronics.
I have secured a classroom in a local educational organisation in the Belgian city of Hasselt.
That is at the Belgian-Dutch border and I hope to get students from that (wider) area.

We will start end of October, and basically have classes two Saturdays per month until next June.
I have selected a first project (design, build and test a phono preamp).
We will go the whole mile designing the circuit, some basic simulation for verification, a PCB layout, building the unit and measuring the final performance.
The goal is that all participants will have a completed unit at the end of the course.

I have a basic website where all is explained and where you can sign up for the course: linearaudio.academy
The website is in Dutch as that is the language spoken in the area, and needs some more work the coming time but the basics are all there.

So, if you know somebody (or yourself) who might be interested in this, please forward this info.
At any rate, I plan to document our progress here.

Jan

Hey everyone.
Been a long-ish time reader of the forum but this is my first post and now would love your input on a build I am going for. The build is for my dads birthday. He used to be an audio nerd and had two little red monitors that he gave to me in my teens. I don't want the 2 towers to be huge so that's why I'm only going for an 8'' woofer.

Now onto my questions: I'm planning a 3 way design: 8'' woofer + midrange + tweeter. Floor standing speakers to give the woofer enough volume (at least 50l). Does this build make sense from a driver point of view? are there better options for any of the parts? Just wanna gather feedback if I'm not looking at something that'll be critical.

my current favorites are the following:
Woofer: Dayton Audio RS225-4 Bass-midwoofer link woofer sens: 91 dB
midrange: Dayton Audio PS95-8 Full-range Woofer link mid Sens: 85.56 dB
Tweeter: Dayton Audio RST28F-4 Dome Tweeter link tweeter sens: 93.5 dB

Then I would build a passive XO to go along with everything and match the frequencies and sensitivities. The FRD files for all the drivers are pretty easily available that's why I decided to start off with Dayton as my first build. Other option would be to go with the Dayton KABD-4100 DSP + Amp combo, but I would prefer to learn by building the XO myself. Add on question: it's gonna be pretty easy going from the 93.5dB sens of the tweeter down to the 85dB sens of the mid using a 2nd or 3rd order XO, correct? Haven't gotten around to simulation that yet.

Cheers!

Curious about these DHTs. Hard to find any information on either but they are in Franks with curves. Anyone used them and can comment?

https://frank.pocnet.net/sheets/060/l/LP2.pdf

Out of curiosity, I decided to model in LTSpice the direct-coupled 6B4G SET published in Lipman's Practical Amplifier Diagrams (1947), which is identical to Don Garber's Fi 2A3 & Fi X. Lipman does not provide operating voltages, nor have I been able to find any for Don Garber's amps by searching the web.

So, I started with a typical operating voltage for the 2A3 (250Vak), using a B+ of 295V. There's supposed to be 45V across R5, which is the grid leak resistor for the 2A3 and plate load resistor for the 6SF5. This results in some pretty unorthodox operating points, with about 15Vak/0.5mA across the 6SF5 and the 2A3 operating at just 5mA. Surely this can't be right?

I've modeled both the original Lipman/Garber circuits as well as Garber's updated one, which replaces the variable resistor R3 and R4 (1K) with a single 5K resistor, and also replaces the 3K cathode resistor on the 6SF5 with a 2.2K (I've verified this change by looking at online gut shots of later Fi 2A3 stereo units). The voltage results are nearly identical in both.

Has anyone built or worked on the Fi 2A3? Does this seem right? Have I messed something up in the model?

I started to wonder, which commercial or diy movable / portable subs have the biggest enclosure in volume, and by movable I don't of course mean enclosures that are a structure that is built to be a part of a building or some shipping containers outside the house lifted on trucks, I am talking about single enclosure subwoofers that you can still move around your room to different positions and even borrow to your friend.

I'll start with my sub that I built almost 15 years ago in Finland, which had a 850 liter sonotube enclosure with a Maelstrom 21" driver. It worked great for low frequencies and at the time I did not hear anyone having bigger one in that country. I do remember someone first had built a 650 liter sub with similar specs. In fact, that is why I built mine one step bigger.

For commercial subs I have no idea how big they get, but if I take a random example with two 21" drivers, this one is 1200 liters calculated from the outside dimensions, internal volume is of course different.

https://www.dasaudio.com/en/products/systems/ux-series/ux-221a/#dt

I have a bunch of projects coming up on my bench and I'm interested in box/case/enclosure/chassis providers. I've perused the standard chinese chassis fare on Ebay, I know of Par-metal (and of course Bud and Hammond) as well as the store here, and I found some interesting options on Amazon ("junction" boxes like this one: https://www.amazon.com/gp/product/B09J2935KZ/ref=ewc_pr_img_1?smid=A28DZI5I4PJFY4&psc=1 - image below since this link may not work for long). I'd like to know what other sources you all use for project enclosures.

I've searched here but the threads for this seem to be minimal. I hope I haven't opened a topic that's been addressed a lot in the past.

Thanks much in advance!
Carlp

Sto cercando di finire un vecchio progetto... ho bisogno di uno o due shunty PcB... saluti

Hi !

I have to replace a fuse in this amp, Rotel RA-930AX. On the original one, is engraved "250v T4A S". What does mean the "S" ? I only found T4A fuses in stores.
I thank you for your reply!!

JB

Hi,

I had a pair of 3-way loud speakers which an audio engineer friend of mine helped me build. I was making furniture at the time and I made the cabinets and he built the cross over network and provided all the plans/specs.

He also gave me an NAD 2600 amplifier which he modified with a huge set of capacitors sticking out of the back, he said they were rare military spec. Anyway, for the last ten years, I've been living with my brother and the whole thing has been confined to my bedroom and so I have not used them much at all.

I've been spending half my time in Greece though and finally am moving there permanently this Saturday. There I have a small 2 bedroom house, the main living area is about 15x25 with a tile floor and 12 foot ceilings. I've got a small klipsch bluetooth speaker which I have been enjoying but am thinking about importing my speakers - the amp has to stay behind because the current is different.

I took apart the cabinets and took out the drivers and the cross over network with the plan to take all that to Greece and build new cabinets there.

It all fits in my suitcase, but I can't take much else and my big question is whether it's worth the hassle, given the age of the drivers, am I better off just buying say a $500 set of speakers that will sound great, not take up too much space and be much less of a pain in the a$$.

Here is a list of the drivers, and I'll attach an image of the crossovers.

Vifa P25WO 10"
vifa p13mh-00 made in denmark
and the tweeter I can't make out the whole number, H1 ..........-06 27tdfc made in norway

I think if I could sell it all, I would be happier to just let it all go to a good home, but maybe I could end up with some great speakers.

Finally the cabinets I built for these were pretty big, like 24" tall, 14" deep and 12" wide - something like that - not exact - all out of 1" mdf. If I put these in a new cabinet I wonder if I could end up with a decent sounding speaker in a slightly more compact box.

Any advice would be appreciated.

As far as I know, there are four manufacturers in China produce the 300B. They are ShuGuang, TJ Music, LinLai, and GuiGuang. Interesting enough each of them have several types of 300B tubes with different price range from hundred to several hundred a piece.

I am very curious how they are different from each other???

Johnny

Happy New Year

I have got a problem with one of my Cremona midrange (not the mid-woofer), that stopped working (tested: no continuity). I managed to remove it from the cabinet using the suggestions that I found in an old post (great stuff!). I have a couple of questions though:
1. There are two 4 Ohm Scan Speak possible replacements for the Mid Range:
(a) 15M/4531K (b) 15W/4531K
The physical measurements are the same as the Cremona driver; however, the frequency response are indeed different with the 15M being about 3dB more sensitive.
https://doc.soundimports.nl/pdf/brands/Scan-Speak/15M4531K00/15m-4531k00-data-sheet.pdf
https://doc.soundimports.nl/pdf/brands/Scan-Speak/15W4531G00/pdf_Scan-Speak_15W4531G00_1.pdf
Am I correct to infer that the driver used by SF is the 15M?

2. In old articles and marketing material, one reads that there has been some "customization" done by SF in Italy. However, details are a bit vague... I get the feeling that in reality, for the first series at least, SF customized/adapted the cross-over to these Scan-Speak drivers? These drivers really look identical... Anybody here knows the truth?

Thanks in advance!
Andy