Hi everyone,

I'm trying to design an enclosure for a subwoofer I found in my house. I measured the Thiele-Small as best I could (I attach the file) and with some calculations I have calculated the opening for the bass reflex of the box.

I calculated the Fb of this box with this formula:

what would look like this replacing values: and it would result in 102,393

Then to calculate the dimensions of the bass relfex, I calculate it with a nomogram, this specific one:


In which the value of the cubic feet of the box is located, and then on the other line, the value of Fb. These two points are joined with a line until they intersect with the third line, from there, a straight line is drawn parallel to the X axis.

So every time this parallel touches one of the curved lines there is, a line can be drawn downwards. And there you obtain the value of the area of the opening, and the depth of the opening.

What happens is that my parallel is on the lowest line that can be observed of the third straight line. Therefore, the smallest option for the aperture is an aperture of 12.5 inches in diameter, and about 2.7 inches in depth, which is quite large, and impractical.
My question is, first, is this whole process okay?
And second, if that's okay, is there any way to compensate the area of the opening, by length of the opening? That's more practical.

Edmond Stuart demonstrated an auto bias circuit and I wonder whether anybody has implemented this within their designs or has any feedback on it?

looking to make sure I buy the right part, It's a blue Film Capacitor that reads 5n6j100.Thanks.

I have one of these little solidstate realistic sa-100C amplifiers. It has distorted sound on both channels. Kind of like the input is being over driven. Thats what it sounds like. I replaced the power supply cap, cleaned all the controls, replaced the cap in the signal path. There is no voltages on the schematic and I can find no inormation anywhere that has voltages listed. Being that it is dostorted the same on both channels is what has me stumped. There is nothing to the power supply and I replaced the cap. Any help as to where to look would be appreciated.

Jeff

Today I tried an idea I had, and I want to share this.
Okay I have some tubes which I wanted to check, some of them had very corroded pins, and probably poor contact, lazy as I am I would not spend time scraping with a blade, so I made a solution of saltwater, striped a piece of old wire clean, wrapped it around the pins of a old ecc83, taped the wire to tube top, wrapped another cable around some aluminium foil and soaked it, minus to foil , plus to tube, 8 volt 2 amps, the photo shown is from just under a minute in electrolysis, legs look much nicer now, except the part where the wire was against, but that part does not enter the socket anyway.
But be careful, to much current and to Long time will eat the pins.
Unfortunately I didn't make a before/after shot.
I had fun..

300W with heatsink ( 60W without ) ARCOL HSR 300 resistors,
7kV ac peak isolated from case, resistor element limited 2500V

72x128mm mountingbase,
41mm hight,
M6 x 20 connection threads,

9pcs NOS/NIB 8k2 +-5%,
5pcs NOS/NIB 12k +-5%,
1pcs "used" 15k +-5% (has been in "use" for one afternoon to take low power measurements)

Asking price for the lot is 200€
If you only want some of the above and for shipping costs (EU ~ €20-25), please mail me

Does anyone have a schematic for a Lanzar Optidrive 150 (Opti-150)? I got one with a couple components burned beyond recognition.

With box and PS. Built a few years back. Configured to 100 hz xover point at 12db with bass lift at 30 hz or so.
I guess that if you are looking at this you know what it is. USPS priority shipping which you pay… and Paypal

When measuring the dispersion of a waveguide in AKABAK, should it be modeled as an external domain with no interface, or as an internal->external domain with an interface? And if the latter, what shape of interface should be used? Both of the approaches seem to give reasonable, albeit different results. Here is the waveguide I am trying to model for reference:



On a somewhat related note, I'm trying to get a 100x80 dispersion pattern for my waveguide. Is it possible to get +/- 50 degrees smooth all the way up to 20 kHz using a compression driver? So far I've had better results when I tried testing a dome instead of a flat driving surface.

Purchased these from Kevin Carter around 2011. Used as interstage transformer in the 6CB5 Se amp published by Thomas Mayer. I have upgraded to Tango, hence surplus to requirements
Wired with C37 treated Silver wire in 1:1 config
Asking US$ 175 for the pair plus PayPal charges. Shipping extra

Hey and servus from Vienna,

I do have 3400 + of them. Plus means there a some opened pouches ....and I didn't count them...

SOT 25 WITH gold legs

Have a nice day

I think about €1700,-

Hi there,
Iam a proud owner of a secondhand Pearl one.
When looking through the schematics of it there is an option
to install a 9V battery between PAD 4 and 5, paralell to the diode 1N4739.
What is the backround?

Hi everyone, I too have a problem with the Klout... I recently changed all the capacitors because one channel was dead and I solved it but this summer a power surge knocked out the Klout. I changed a broken diode but before giving power to the amplifier I would like to have it tested by an electronic engineer friend but he asked me for the electronic diagram.
Do you have any information about the schematic and where to find it?

Hello and greetings to all! I've recently joined to help showcase some of my latest designs. I design, build, sell, and repair all things vacuum-tube!

I've attached a few photos of my most recent builds for attention. Cheers all! Stay tuned for more posts and feel free to reach out with any requests or questions!

Brian Proulx
Proulx Audio

1 pair Lundahl 1660/18ma interstage/line out transformers.

Very briefly used.
$200 net to me, with shipping to continental US already included in the price.

Is it possible to build a "bad" 45 amp? I recently built a pair of PP45 amps with a 53 transformer coupled driver and an 80 rectifier, adjustable bias, very old-school. The iron is ISO and Lundahl. I've built a lot of amps, but I think these beat them all! About 6 watts before clipping, but they sound much more powerful. Listening on EV Aristocrats right now, but they also sound great on my Cornwalls.

Hi I like to build prototypes like mid horns, midbass horns and folding horns. Interested in line array as well.

Hi,
I have just got hold of these speakers.
They have bass and treble but a whole range of mid-bass is missing. Noticed immediately when the oboe in King Crimson’s “I Talk to the Wind” was entirely absent!
What would cause this and how could it be fixed. I assume a crossover issue as I have bass and treble so the woofer and tweeter are functioning.

Hi All: Havent posted in a LoooonG time but need some help. I am building a simple RH84 from Kitic's excellent board but having troubles with a suitable power supply.
Being a poverty-stricken oldster, I cannot afford to eBuy a proper power transformer. Luck hooked me up with an ancient Marconi 224 radio, from which I have salvaged a working transformer and a healthy 5Y4G rectifier. My problem is this:
Transformer has the following outs: 5Vac, 35Vac (heaters are in a string) and 680Vac CT.
Wired up the 5Y4G with C-R-C (150uf, 470r, 33uf, 400V caps) and I get 450Vdc .
This is odd because the Marconi schematic shows the original PS caps are rated at 20uF/300V and 30uF/360V.

Tried a half-wave 1N4007 on one side of the HV out (measures ~340Vac). I was going to create two separate PS circuits each using one half of the 680V CT windings.
Wired this up for one side to test C-R-C-R-C (150uF, 470r, 0.47uF, 470r, 33uF) from this trafo and get 447Vdc!
I can't understand why the output measures so high in either case.
I have modeled this and other configurations on PSuD and it predicts 312Vdc out at 112mA - not even close to what I am measuring.

I think that this whole thing is hinged on the load (both the real and simulated). For PSuD I have guesstimated the load at 5K, but this is probably miles off. I have noty been able to find any infor on the actual load an RH84 presents to its PS. If anyone knows that it would help a really-really lot.

As you all probably know, I need 315V/100mA for the RH84. Can anyone explain a) why the outputs of the two configurations measure 400V+ and b) how I might drop the PS Output without restricting the current too much?

Cheers all
Jess

Usually I see quite similar positive and negative spikes in impulse response graphs. I am modeling a driver in Hornresp and I get a very different looking asymmetrical impulse response (+9 -3). What does this mean? Is this good or bad?

Hi!

I have been working on a little project to to turn some of my spare speakers (SS-MF500H Specifications | Sony AU - 8 Ohms at 180 Watts) into a bluetooth system.

I am using a TPA3116 (2x 100 Watts) from Aliexpress ("1002 Hifi": ZK 1002 HIFI 100WX2 TPA3116 Bluetooth 5.0 High Power Digital Amplifier Stereo Board AMP Amplificador Home Theater|Integrated Circuits| - AliExpress).

For power, I am using a 19V with 3.67A laptop supply but also tried it on my benchtop power supply with up to 21V and 5A.

It works mostly as expected, but there is one little thing that I just can't understand. The sound quality is average at best, hence I measured the Watt consumption and even at full blast (it does get pretty loud), it only consumes around 2 Watts in total.

I am completely new to tinkering with audio, but my understanding is that it should use way more power than this (which should also result in better quality audio).

Would anyone be able to help me and point out what could be wrong - or maybe the board is just broken?

PS: I only want to achieve 'decent' sound (i.e. nothing audiophile), but I do want to make full use of the parts, meaning getting close'ish to 65 Watts at full power.

I bought a Chinese amplifier from Wuzhi Audio brand and I even bought 150 W. My problem is that when I connect via Bluetooth or AUX, the sound of music comes from the body of the devices. Whether I connect speakers or not.

Translation: I bought a Chinese amplifier from Wuzhi Audio brand and even got 150W. My problem is that when I connect via Bluetooth or AUX, the music sound comes from the body of the devices. Whether I connect speakers or not

Hi All,

I’m pleased to announce that the “Sound DIY Club” will be sponsoring “The Puget Sound DIY Speaker contest” this year. It will be hosted by the Pacific Northwest Audio Society (PNWAS), at its current meeting location in the lower level of the

Kirkland Congregational Church
106 5th Ave,
Kirkland, WA 98033

The Contest is scheduled for Saturday, October 5th, with the doors opening for registration at about 11:00 AM and the general public at approximately 11:30 to 11:45. We will attempt to start the judging at 12:00 noon.

More details follow:


What Will Happen?

The Contest will be held at the Kirkland Congregational Church, 106 5th Ave, Kirkland, WA 98033.

Doors open at 11:00 a.m., and judging will begin around 12:00 noon. We may be flexible on start time if a contestant is traveling some distance and may be arriving later than the start time; please let us know in advance so we can schedule accordingly.


Entries

There will be two "classes" of entries: original DIY designs and kits. We realize that a lot of effort, experience, skill and sometimes luck are needed to come up with a successful design. Many accomplished designers learned their craft by starting with kits of one sort or another and subsequently progressed toward original designs. For others, the lack of time or experience makes a kit a means towards better, affordable sound.

Also, if you can bring speaker stands, that would be helpful.


A Kit is defined as...

...Any pre-designed or published design (publication includes the Internet) that is the product of another person. This may be plans, parts, kit, or both plus cabinets, etc. Any major deviation from the plans may at some point constitute an original design -- however, a club appointed technical committee will have the final determination if this problem presents itself. All kits must have been offered to and available to the general public at some time. We rely on the integrity of the contestant!

The kit class is broken down by cost per pair and excludes the cost of the cabinet and finish. The breakdown for kits is as follows:

$0-$175/pair
$176-$325/pair
$326+/pair


Original Designs:

The breakdown is as follows:

One way ----under $75/over $75
Two way ----under $200/over $200
Three way -- under $300/over $300
Unlimited ---- no limit

NOTE: This is for drivers and crossover parts only; cabinet material and finish are not included. We again rely on the contestants' integrity. Your uncle who owns the HiFi Emporium cannot give you a special deal that isn't or hasn't been available to the general public. Nuff Said!

The speakers will be driven by the system supplied by the club. Don't bring your own Megawatt Hyper Triode Amp -- we're not going to use it. To keep it simple, we are not going to allow biamping or plate amps for a bass module.

The entry fee is $10 to register at the door. If you have any questions please post on one of the forums with an official thread on the contest, like this one. Also, it would help us a great deal if you'd let us know or think you're coming.

Judging

The judging will be by a panel of judges in a special room set aside for this. We will have three judges, which in turn plays his personal pre-selected musical selections (2-3 minutes max.) while sitting in the "sweet spot." Each contestant is allowed to specify general guidelines to set-up, that is, distance apart, toe-in, although corner loaded speakers will need to provide their own artificial corners. Remember that the judges will be sitting side by side so that should be taken into consideration.

We intend that judging will be totally blind -- this means that a curtain is utilized to ensure that sound, and not appearance, will be the sole criteria. All speakers will have the loudness adjusted to the same level before judging begins. Set-up of speakers will be by a club crew using notes taken at time of entry. Each judge will be issued a standard evaluation form prior to each session, and will rate each entry by assigning points, after which the form is collected by the Technical Committee member assigned to monitoring the judging (and setting SPL levels prior to each evaluation of an entry, etc). The forms are then scored by the Contest Director, or his designee for total points. After the final entry is judged, the points earned are assigned within each category to determine ranking within that class. The total overall points regardless of category or class will determine Best Sound of Show.

Other Stuff:

General admission of the public is free. We hope to have a garage sale/swap meet type offering for those who wish to sell or buy audio gear for free. However, the owners are responsible for their gear, etc. Don't expect to drop off stuff and return at the end of the day to pick up the money. (Please advise in advance if you wish to sell items).

We are going to let the attendees help out by voting for the Best Craftsmanship, Most Unusual, Most Creative Use of Material (Bondo, duct tape, silly putty, etc.).

Awards:

Each entry will receive a certificate of participation and a print out of the entry's frequency response measured by a qualified expert designated by the Contest Director or head of the Technical Committee. Additional certificates will be awarded to class winners, as well as 2nd place .

Finally a "Best Sound of Show" certificate will be presented to the overall winner. All winners of their respective DIY class are eligible for this. Please note that "kit" speakers aren't eligible for the Best Sound of Show.

Unless overruled by the Technical Committee for violation of the rules, the decision (total points) of the judges is final.

Best Regards,

TerryO

Is the um18 22 the daddy for 30hz down?
No other driver models like it..I have been looking for 18s-21s QTS 0.4 ish for sealed subs. but nothing beats the um18.. I have rosso 21s and they need room gain to perform where the um18 does not.. These are the only drivers I have heard. So what driver would you try?? B+C 18 IPAL? expensive! Are drivers for sealed subs rare?

I'm curious about your opinions................

I'm going to get a big sealed stuffed box built (golden ratios), think 36" tall x 22" wide x 14" deep.

I would like to get the full range driver to be higher off the ground, as these will be used for low volume movies maybe 1/5 of the time.

I measured my ears @ around 42-43" off the floor and the middle of the TV is near 40".

I see the seas f8 exotic article on TNT had the (expensive) driver right at the top in a 40.8” tall x 9.96” wide x 11.22” deep sealed box (basically a sealed pipe to me) ................
"........Going back to my own Dynaudio Contour 1.8 mk2 speakers after a while was a shocking experience. Their bass sounds quite boxy and over the top compared to the SEAS............"

https://www.tnt-audio.com/casse/seas_exotic_e.html



Whatcha think ?

$90 for both. + shipping cost , USPS priority, PayPal. Very good condition. Ideal for a Ripole subwoofer project. Bought these from Madison around 2 years ago now out of stock…. Looks like forever, difficult to get.bu

Have a look at the schematic for Rotel RCD-975 (dual TDA1305) CD player (mid 1990s ???).
The serv. manual is a bit hard to follow from the way it is presented. In any case ...
The RCD-975 uses one TDA1305 for each stereo channel. (The 1305 is stereo dac with WS input).
The WS (combined -- single wire), signal from a SAA7310 decoder.
It is a bit unclear in how L/R data is presented to each L and R dac (WS) input.
On page 12 of the SM, there seems to be some massive 74HC glue logic going on. Not sure how much of this is related to slicing up WS into L and R separate components. Didn't know this was possible on a glue logic level. Maybe it's trivial. I've never seen the TDA1305 used in a such a way (two: L and R separate channels).


PDFs SMs here:
https://www.hifiengine.com/manual_library/rotel/rcd-975.shtml
https://elektrotanya.com/rotel_rcd-975_service.pdf/download.html

I have a mint condition miniDSP SHD with Dirac Live.
It still has plastic on front and top, hence "the faded look" to top and front display

This is miniDSP's most advanced device currently with Streamer, DAC, Digital crossover, Room Equalization All-in-One Device that can front a complete stereo system
With 4 Balanced and 4 Single end inputs
2-Way digital crossover with advanced Dirac Live Room Correction / Equalization
Stereo Analog inputs for your Turntable as well

****SOLD

Has anyone here ever built your own KEF KUBE 107, or used the kit? Since it’s extremely rare. I once found it but couldn’t afford, cost is about 600 USD. Anyone has its schematics, pcb layout, part lists, could you please provide us? I’ve already owned a KUBE 104/2. Its power supply is 220V version, part no. SP2123. If I built the KUBE 107, can I use it with my 104/2 Kube’s power supply?

Hi, I came across a china made Hood 1969 amp full assembled kit - but it seems to use BUX41 for the output transistors - looks like a high speed high current. switching transistor meant for military / industrial but not sure if good as an amplifier transistor - Datasheet attached.

https://www.alldatasheet.com/datasheet-pdf/pdf/22120/STMICROELECTRONICS/BUX41.html

It seems these kits started out with used motorola 2N3773 transistors harvested from other boards, then moved to 2N3055/2N9255 (maybe counterfeit) and now BUX41's

https://www.aliexpress.us/item/2251832538128541.html

Any suggestions? Also how hard would it be to swap out the BUX41's for a different output transistor if I wanted to go that route? (Adjusting current etc - assuming the boards have necessary pots)

Thanks

ES

1 pair of Lundahl 2753/25ma interstage transformers.
Brand new/never used.

$240 net to me

Well, as the title suggests I have the usual problem that also occurred with a previous amplifier I made... I suppose it can be the magnetic coupling between the power transformer(s) and the OT's.
Or rather it is more evident in the speaker coming from the central OT (closer to the toroidal tunnel) than in the more external one, and therefore further away, where the hum is barely perceptible to the speaker by placing an ear upon the cone.
I had told my carpenter friend to make me a wider frame, but he was wrong with the measurements and I had to settle with that...

Now my question, to avoid running into the same problem in the future is there an optimal method to minimize this coupling? I mean orientation between transf and (possible) power choke plus suitable spacing between these elements...

The support plate is made of aluminum as is the toroidal cover.

Thanks in advance

I recently serviced a Technics SA-5760. New caps, diodes, transistors, etc where appropriate. I worked fine for a couple of weeks. Then the output relay wouldn't engage. It turned out that one of the few transistors I didn't replace (input differential pair 2SA798 (combined housing) on poweramp board) crapped out. I replaced those, the relay works once again, but now I'm faced with a right speaker output that clips on the positive side of the waveform at about 1,2 to 1,5 volts, depending on the temperature. Thinking it was a problem with the output transistors, I swapped them with the other channel, but the issue remained. Everything looks and measures fine. No odd or missing voltages as far as I can tell. In a move of desperation, I began swapping out components with the other channel, but after all transistors, caps and the NTC were swapped, the problem still remained. I hope someone with maybe expierence with this amp or similar can offer some advice. Any insight or guidance is more than welcome. I attached the service manual below.

For sale!Used but verry good condition.The contact wires are around 40 mm long.Price 40 euro + 4,70 shipping inside EU!I buy this around 6 month back from Darisus gmbh Germany!

Hey, just working on a multichannel amplifier and wanted some insights on a speaker protection and short circuit protection circuit. I do plan to expose Q11 and Q12's emitters for current sense. I plan to have no more than 100w into a 4 ohm load. So just wanted some suggestions or ideas. I did have a look into VI limiters which could work as a 1st order overcurrent protection?

The wife has decided a tv is needed in the bedroom. So the large 12" pioneers wont fit anymore. Due to drawers, doors, etc I have only 5" both sides, and ~16" deep, but 36-48" tall.

There is an additional 9" behind the tv as well. Ive added a sketch of the working volume.

Would like to get close to the ol 20hz-20k (a sub is allowed if it fits) normal volume is only 60-70,db. But 85-95 db would be nice at 10-50watts for special occasions. No DSP, passive crossover.

Have built 3 sets of 2way ported+CD horn, and a cornscala type build, and half dozen sealed subs. Would like something different! But not too crazy.

Been checking out the Cyburgs-Needle, Perry's shaded array, the bourbon barrel, frugal array etc... all slim stuff.But would love to use more of the space behind the TV. Would love todo some horn stuff.

Budget wise 500usd max 250usd preferable, cheaper with an upgrade path is nice.

Thanks for your thoughts!

Good morning everyone!
I would like to know if by chance someone has measured the impedance vs frequency of the secondaries of a power transformer
I read a statement that left me perplexed
And that is that the power transformers should all be with separate coils while the output ones of a tube amplifier toroidal with coaxial windings
In the sense that the former should have a narrow impedance curve while the latter have a wide one
In short, I'm a bit confused
To be honest i have just purchased a Dayton Audio Dats v3 impedance meter that could be useful
In short i would like to replace mains transformers with better ones But i have no clue about the best option
That should be one passing only 50Hz ? 😊
Maybe there is an industrial grade one out there that could be fantastic for an amplifier
Who knows ?

Hi.

Just curious - I currently have two sets of speakers, a pair of old Mission M66i, and a pair of B&W 601. The Missions have domed tweeter cones in a very soft pliable material, and the B&Ws have metal cones, much less domed.

How can they be so different?!

I'd have thought that the firmer material of the B&Ws would project the higher frequencies better, but the Mission tweets work just fine too. How can such a soft material project so well? Why are their designs sooo different?

Thanks for any insight 🙂

Hi,

For simplicities sake, I'm starting my journey with my used pair of Wharfedale 9.0 speakers. Nice speaker for the money. So crossovers are removed and separate amp channels for each of the four drivers, protection caps on the tweeters.

Let's keep everything to Windows and use my MiniDSP UDAC8 and UMIK-1.

Let's use CamillaDSP for the crossover.

So I'm looking for a new speaker PC DSP new speaker basic "software" test checklist, does such a thing exist? Software product agnostic would be best, where a free package is available to do the task it would be great if that's mentioned?

I think I would run some measurement tests to find the best crossover frequency, correct any channel volume imbalances, remove any channel delays, flatten its response?

So in plain English, ordered steps, the what and the why?

I'll add a separate sub later on, what does that add to the checklist, phase?

Thanks!

For sale is Denon AVR-4700H with all the accessories.

The unit is in like new condition.

I'd be glad to demonstrate the operation of the unit on a Zoom/Teams/FaceTime call before the pick-up.

The picture shows on the unit only.

Please send a private message.

I read this on diyAudio. ( Got interested, then confused.)

Take a guy who has decided to provide 20,000 uF per rail. He can do it one of three ways, at fairly similar cost. He can put in one big 20,000 uF cap; or he can parallel a pair of smaller 10,000 uF caps; or, he can put in two 10,000 uF caps in parallel, but separated by a 0.22 ohm resistor. If you do the ESR math, the last approach is about 10 times better at filtering the nasty stuff, although total energy storage and p-p 120 Hz ripple are similar in all three cases.

How can "the last approach be 10 times better at filtering ....although....p-p 120 Hz ripple are similar in all three cases" ?
What ESR math ?

Hi all!
I just wanted to run my design for my preamp past you before I commit and send of for final components and PCB's 🙂
make sure everything is safe and works as intended, here is the schematic of the power supply:
And the preamp:



I will add another board for input/output switching and a relay delay on the output.
The low output impedance is needed for my usecase as I'm driving a MOSFET source follower to the speakers and will be experimenting with different output stages in the future.
I am a little concerned about gain-matching the L R channels, and have considered a bypass capacitor and trimmer pot in series with R10 in order to address this.
What do you guys think? any input is much appreciated.

Well now that I have actually figured out how to wire this amp correctly(polk monitor 5s run in 120w bridge mode using channels 1 and 5) I want to connect my two acoustic monitors Into these center channels(3 and 4) in non bridge mode(60w) Does anybody have any advice on what I should do about that lower left broken nub of a speaker attachment? Should I just solder on a wire and twist it to the speaker cable? I know that's ghetto, but The Thing is completely broken off practically and I don't think I have replacement options for it

Hello.
I bought the bluetooth DSP Blenchance 2.1, when I save my settings the red light does not flash twice, but if it is saved for several minutes/hours, after that period of time it reverts to a completely random setting.

Additionally, it presents digital noise that can be easily perceived at low volume levels.

Does anyone know how I can correct these problems?

I am using ACP Workbench to configure it.

Does anyone have an otto 2 kit?

Hi everyone!

I am new to the DIY audio world, but have been dabbling in audio for some time. I decided a few weeks ago to try my hand at building my own bookshelf speakers, but have frankly been overwhelmed by all of the options out there! I need some help narrowing down some options that may work well for me and my application. I have access to a full wood shop and electronics shop, and should not be limited by tools much and not scared of tackling complex cabinet designs.

Here is the criteria I'm working with:

• My budget is <$1000 for the pair (incl. drivers, XOs, cabinets, etc.). I do not mind paying for plans on top of this.
• I live in the USA, and would prefer to order components from US based distributors, but can make exceptions if warranted
• They will primarily be used for home theater/TV, so would prefer some decent bass extension (down to 50-60Hz would be good)
  • I may later repurpose these for primarily music, not sure yet. OK to modify them in that case.
• These speakers will be used primarily close to a wall (within 9inches) on stands
• The room is approx. 15'W x 13'D (~4.5m x 4m), and will be placed centered around the TV on the 15' wall
• Listening position will be near the opposite end of the room (~3m away)
• Not particular about driver configuration: 2, 2.5 or 3 way could work
• No more than 400mm tall, preferably <300mm, and max ~350mm wide
• 4ohm is OK, and will likely only be driving them with a Yamaha RV6A for now

I am not quite sure how much has changed in driver technology and performance, so I have been trying to look around for more modern drivers. Perhaps this is naive of me, and some of the drivers from the last 10-15 years are still good value performers?

I also do not need to spend the full $1000 on a speaker set, if there is a really good $500/$600/$700 option, I would definitely consider it.

I love many of the Troels Gravesen designs, like the ScanSpeak Revelator-51 but I'm hesitant to import many of the components that I can already purchase in the US.
Some of the lautsprechershop.de designs look great, but couldn't find some of the components in the US.
The "Revel M105 Copy DIY build" by McFly on ASR also seem really cool, but I'm not quite sure whether I could build something even better with my budget.

Thanks for taking the time to read my post; can't wait for the feedback and suggestions from the DIYA community!

Hi All,

Ok so this is my first post here so Hi. Picked up an Audioromy m828a FU29 tube amp from ebay - came quick, seems pretty well made.

I wanted to get the Bias and Balance right before I started using it extensively, so went about looking at it's guts. It seems the one I have differs from the schematics I have seen and the photos of the PCB apart from one person on this forum about a year ago who had gone about a similar question.

It does seem that the information been put out by some of the sellers of this amp is not compatible with what is actually in the unit. I wasted a lot of time stupidly trying to bias via the cathode, as there seemed to be a 0.4ohm resistor there (evidently not really). I could not get a real mv reading across to determine adjustment to get to 50ma total on the combined cathode.

So the 829b tube has a single common cathode and two anodes, essentially two tubes in one. It looks like the more recent versions of this Audioromy amp have no resistors for the cathode to determine the current here, but instead uses 1ohm resistors on the anodes for each half of the tube?

The attached image of the PCB area for one tube (from the other thread but is same as mine) shows the anode resistors and the white wires heading off to the top of the tubes.

The other attachment shows the instructions that have been sent around from the various sellers about how to bias the unit.

I suppose my post is here to highlight this disparity to anyone else who may have been confused about this and also to ask, can I adjust the bias and balance correctly via the supposed 1ohm anode resistors???

If it were a case of a simple in at cathode, out at anode analogy, I see how it wouldn't make any difference where the mv reading is taken? However what with the screen, grid in between the two, absorbing some of the juice, this reading might not be correct?

When talking about tube ratings, is the 50ma applicable to this tube in terms of cathode current or is it a more general cathode / anode current, making the location where this reading is taken irrelevant?

I am new to tubes since about a few weeks ago, so have a hell of a lot to learn and will refresh my basic electronics knowledge in the process.

Appreciate any help on this as I am going to attempt to bias / balance these tubes tonight and do it properly (ideally a self balancing circuit would be my solution?)

Cheers,
Rich.

$299.00 OR BEST OFFER - Price too high? Make a reasonable offer and you'll probably own them.

This lot features 13 hardback books from the Gernsback Audio Library:
1. UNDERSTANDING HI-FI CIRCUITS, Norman Crowhurst, 224 pp, 1957.
2. HIGH FIDELITY CIRCUIT DESIGN, Norman Crowhurst & George Cooper, 303 pp, 1957.
3. AUDIO MEASUREMENTS, Norman Crowhurst, 224 pp, 1958.
4. MAINTAINING HI-FI EQUIPMENT, Joseph Marshall, 223 pp, 1956.
5. BASIC AUDIO COURSE, Donald Carl Hoefler, 223 pp, 1955.
6. AUDIO DESIGN HANDBOOK, H. A. Hartley, 224 pp, 1958.
7. INSTALLING HI-FI SYSTEMS, Jeff Markell & Jay Stanton, 224, 1960.
8. TAPE RECORDER CIRCUITS, Herman Burstein & Henry Pollak, 223 pp, 1957.
9. CLEMENT BROWN’S INTRODUCTION TO STEREO, Clement Brown, 188 pp, 1960.
10. STEREO… HOW IT WORKS, Her,an Burstein, 224 pp, 1959.
11. THE STORY OF STEREO: 1881-, John Sunier, 160 pp, 1960.
12. DESIGNING AND BUILDING HI-FI FURNITURE, Jeff Markell, 224 pp, 1959.
13. HI-FI MADE EASY, Norman Crowhurst, 224 pp, 1959.

Books show some wear.
No musty odors, pages are clean, I did not see any writing.
Sold AS-IS

$24.00 shipping to USA lower 48 states. I do ship worldwide, please see below.*

I am experienced in packing and shipping heavy gear. It will be packed in a strong box, surrounded by styrofoam, secure in box without movement. Shipped promptly, tracking shared, safely packed. Gear will be padded on all sides and secure in box, care will be taken to protect anything that stands proud of the surface, knobs, switches, etc. I pack to preserve this irreplaceable, cool, old gear.

To make purchase message me and I’ll send you a Goods & Services invoice from PayPal, Venmo or Cash App, please indicate your preferred payment method.

*re: International Shipping. Due to the unpredictable nature of Customs in different countries i.e. long hold times, seizures of gear containing vacuum tubes, selenium rectifiers, mercury rectifiers, leaded solder, etc. I must be paid via Paypal Friends & Family for any shipment that leaves the USA. I will not bear the risk of the gear being confiscated. If you are OK with this, please send complete address for shipping quote. I am happy to ship worldwide and well experienced.Items sold AS-IS are not eligible for return or refund, all sales are final, no warranty or guarantee expressed or implied. Payment for this item constitutes your understanding and agreement to these terms.

Pick up in person welcome, no shipping charge.
Litchfield IL, USA

Hi, is possible to bypass internal DSP on the zapco DC 350.2 amplifier?

Hello all, this is my intro post. Long time reader never posted.

I was perfectly happy with my B&W towers and AVR when, in a coffee-shop in Seoul I heard to some intriguing sound. It was coming from a valve amp (and a couple of uber-expensive Western Electric speakers) and after coming back home I tried to replicate that bewitching sound in my house. I procured myself a cheap valve amp but the sound still wasn't what my ears could remember. I decided that I needed more efficient speakers and that's when I fell down the slippery slope that is DIY speakers.

Since I wasn't going to spend thousands on high-efficiency speakers I tried to make my own. I then discovered the Lampizator blog and that convinced me to build the Endorphine P17. Huge success... I was so happy with them that I decided to upgrade my humble EL84 SET and got myself a Line Magnetic 300B amplifiers. After more than 7 years later I still use the same combination for my main system.

During that time I built a similar speaker to a friend (who fell in love with the Saba greencones and the valve sound), following the OB path I built three sets of speakers to friends using the Martin King OB design (with the fostex and the eminence alpha). Learnt a lot along the way about passive crossovers and Thiele-Small parameters, room correction, etc. I successfully built some variations on the Endorphine theme, and also on a two way configuration (but to be honest, it was just luck that it sounded good). Siegfrid Linkwitz blog convinced me that, to strive for perfection, you need to go active. But so far I've never tried to build any active system (seems too pricey and I don't want to give up the tubes). However, the clarity of the class D power amps I used (Icepower and Hypex) lured me enough to make me think of getting rid of my 300B amplifier.

Since my ears need that level of 2nd order harmonic distortion I have attempted to build several valve preamplifiers. Always got noise issues. Learnt a lot in the process. Bought some good books from Merlin Blencowe which helped me understand what I was doing. I still couldn't get rid of the noise completely (on sensitive speakers) but getting there...

I wasted a lot of effort trying to build a MLTL using a full-range driver. I never managed to make it sound good but.... I learnt a lot in the process.

I will try to post about all my failures and see if I can get any good advice from anybody who may have tried similar things and managed to succeed.

I have an elan z660 with minumum 8 ohm load per channel indicated. It's been shut down for probably 5 years due to damage to my speakers by my dogs when they were babies. I decided to fire it back up since one of my Polk monitors is still good and figured why not get the owner's manual? Well, it turns out that I had no idea whatsoever How to use the bridging function Or how to wire my speakers to it correctly the first place. I don't think I damaged it because it still works and I never noticed any obvious clipping.. My question is how the hell should I hook up The monitor fives and the acoustics while running bridging mode? If I hit the bus switch, all six channels fire up, So if I only wire each set of speakers to 4 of the channels, that Will leave two of the channels receiving signal and presumably pushing output with nothing connected to them. I hope this makes sense. I'm going to include a picture as it's currently set up with just one speaker at 6 ohms in bridging mode, sounds good for now. I guess it's not as simple as just connecting all 4 speakers to the plugs in the back, LOL.

Yesterday I was thinking about how to fit larger horn parts to my CNC and then I realized that if I use more sides than just 4, I can get a larger horn with the same axial length parts. I originally thought about 6 sides, but 9 seems to look really cool. It is now just a design study - 1" or 1.4" driver, 3 x 3 - 4" mids and 3 x 8 - 12" for lows. All will stay open backed (due to weight and ease of buiding) and maybe there will be even an ambience tweeter in the back. The diameter will be around 100 cm, depth around 60 cm with a coverage angle of 75 degrees (or somewhere between 60 - 90 degrees), I could not fit a larger one in any of my rooms anyway. Even this one will be hard to move through the doors.

I would like to do it "right", following all the MEH rules and do lots of simulations. At my normal indoor listening levels, these will be able to play down to 30 Hz (with EQ) even with open backs, there is plenty of subwoofers around the house that could be used if needed🙂 I see these in stained birch plywood (12 - 15 mm), prototype will be built from 16 mm chipboard.

Should I really need a box, I could build one with 8 sides and fit a rectangular box around it with 4 (triangular) ports in the corners.




This design is constantly evolving. If anyone is interested in the 3D models and OpenSCAD scripts, send me a PM.

Hi guys
I got a LM4780 Amp from AliExpress. It sounds really good but I wanted to skip the cheap volume pot and hocked up the wires directly to the coupling caps, but no sound at all.
I am feeding it from a Wiim Ultra with 2 volts rms output.
Anybody a clue what's going on?

Hi I have an Alpine mrv f300 on the bench.

The amp switches from blue led to red when remote is applied.

I found a shorted 47uf capacitor E3701
After removing the cap the amp powers up normally.

I replaced E3701 and it immediately expanded and went up in smoke.

Attached are pics of the cap location and associated circuit, amp is 4ch digital.

What could be causing the capacitors to fail?

Thanks in advance

ALL SOLD. A FEW ITEMS LEFT IN MY STASH IF ANYONE IS DESPERATE.

Quite a few PSU boards available

1) Talema CRC dual boards for discrete or normal 78xx / 79xx regulators. Designed by Prasi for me these have been excellent powering my Miro DACs. Made for small 7VA talema type PCB transformers 50mm square.

One side is dual polarity +/-, the other is for +5V / +3.3V or what ever you need. The sides can be split apart (FIRST BIG GREEN BOARDS IN PIC)

£5 PLUS SHIPPING.

2) Cap Multi boards by Prasi - Mark Johnson circuit - High power versions and also medium power versions with LT4320 bridge and SMD parts under boards. A few medium versions have SMD parts fitted.

High power - £2 each
Medium power - £3 each



3) Prasi LT4320 bridge PCBs - high power and SMD versions, also PCBs for IXYS qigh quality Bridge rectifiers (white boards)

all £1.50 each or £10 for the lot.

I need a pair, genuine, of course, if anyone can help me out for a reasonable cost

Thanks

Hello. I about to buy a set of these classics. But the rear woofer in one speaker is not orginal. Does anyone have one to sell or does anyone know of a replacement that will match? Are front and rear the same? Asking cause I have seen 4 woofer to first gen M1 on ebay,they were 2 different types..sorry for bad english,I’m from Norway

Filip Eriksen

Mein Name ist Christian, Elektrotechnikermeister aus Bayern.
Nach langjähriger Pause mal wieder etwas Zeit gefunden, um die verstaubten Projekte langsam auf Wohnzimmerniveau zu bringen.
Danke für die wertvollen Tipps, die ich als Mitleser bisher sammeln konnte.

I haven't really narrowed down what I'm after. Building a belt drive with a high mass platter. Was considering the sota total eclipse package.

If you have something that may work, please let me know.

Don't feel I really have it in me to start something from scratch right now.

What is the math(s) used to design the waveguides behind the Nautilus loudspeaker. Is it a 1/4 wave design that tapers to a point? Does volume not matter? Is it a sealed or t-line enclosure? “Experiments showed that tapering the horn shape and then curling it up would perform just as well but would occupy a much smaller volume than a straightforward, constant cross-section pipe. ”



This got truncated. :/

I'm building a preamp using AMB Labs LCDuino-1 https://www.amb.org/audio/lcduino1/

It requires a remote the work with the RC-5 protocol. I'm looking for something HiFi like, aluminum, nice feel etc etc. Below is the best I could find. Does anyone know of another remote or kit? Or possibly something touch screen based that you can customize and program.

https://www.aliexpress.us/item/3256...0035107.1005003975141324&gatewayAdapt=glo2usa

What models do you use in your projects, range 10-50K?
Thanks.

After 20+ years of searching, I finally found a Vendetta Research MC Phono Section. This is the SCP-2A variant in 4 boxes. I will show modifications / updates in this thread. My plan is to stay true to John Curl's original design while updating caps to get decades more life from this unit.

Current plans include:

• Replace all electrolytic caps. This looks like it will cost about $30 + some tax and shipping
• set loading to 100R (same as my PassDIY Pearl 2, Pearl 3, and RS Xono 2019)

I may get a single faceplate fabricated sometime in the future, that's not top priority.

MarkAudio MAOP11, 6"(15cm) full-range masterpiece, was installed in a Stagger Damp-Duct Backroaded-Horn AD (adjustable duct type SDDBH), the final form of backroaded-horn type.

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Hello all,
any info for Piemme interstages are welcome. Sound quality, etc. Thank you.https://shop.piemme-elektra.it/categories/373/products/8690

I have a selection of electrolytic and couple of large polypropylene capacitors surplus to requirements. See photo.

All are unused except where stated and less than 5years old. All from UK distributors, non from China.

raadial / press in.
470UF 250V x8 42mm x 25mm 10mm pitch
470 250v x2 30mm x 25mm 10mm pitch
470 400v 45mm x 35mm 10mm pitch used
100 450v x1 25mm x 20mm 10mm pitch
47 500V X 4 30mm X 15mm 7.5mm pitch wire leads


Axial wire leads. (not shown in photos)
100 250v x4
10 450v x2

Box polypropylene
50uf 600v 50mm x 40mm x 28mm 4pins

I prefer to sell all 24 for £32 (under half price) + £4 for UK postage. (£10 for EU)
I will include some capacitor clips freebies if I can find them.

All are from UK distributors, non from China.

PM me please iof interested.

Thanks

Im considering buying a Forte model 3 amp, but for some reason they are a lot more expensive on the used marked than the 1A...
I have been reading a bit about some of you converting the model 3 to 1A, but have not seen any mentions on the other way around.
Is it possible, and is it a difficult operation? What kind of equipment do I need for this?

Heya all!

I've been building mainly headphones for about 3 years now, and I am starting into speaker design. I am fairly confident I am pretty good at what I do considering I work in the Audio industry for CAD modelling for In ear Monitors, but I just wanted to ask about there being resources on a specific topic:

Building speakers from scratch - the voice coil especially.

I know this is a bit of a rabbit hole, and potentially a very dangerous one. However, it is one I am wanting to go in to. I have contacts for headphone and loudspeaker magnets, so I am all sorted there, and the structure of the driver is easy done. The membrane I can easily figure out myself, but the voice coil is a little daunting when it comes to headphone design. While I understand it is easier for loudspeakers considering the lower impedance, are there resources available that I can be given a shout for headphones? Like how much length is
needed to get to a certain impedance, and what material it should be attached to so the coil doesn't break apart. Other additional info would be helpful!

I have spent the past few hours looking into this topic, and the headphone subject has incredibly scarce information which is why I am here. Just need a bit of help on the voice coil and I would love to update the progress in this thread.

Thanks!

Hello everyone, I'm new to this forum, I'm looking for up to 100 pcs of a Hydrogen Thyratron Ceramic Tube 8765.

SemperFi I believe your thread above from 2021 you said I happen to have some hydrogen ceramic thyratrons, if you still want to try that... it's JAN 8765 to be specific.

I know this is a longshot but do you still have them? Does anyone else from this forum have any of theses that they want to sell or know where I can find any?
Any help would be greatly appreciated.

Today I feel like the biggest idiot in town.

I have below the desk the first part of an amplifier for my active 3-way. I made a couple of months ago the first 2 LM3886 pcb's and put them in an old 19" rack I had around. At that time I also wired up the transfo, a little board with fuses, the rectifier/capacitor pcb, mounted the LM3886 pcb's to their heatsinks and mounted the heatsinks on the chassis. Because I missed some connectors it then went under the desk and other projects took over.

Now I pulled it out, fired up the psu and checked if that was ok. Made the wiring for both LM3886 pcb's and connected the first one.

Switched on, no bang, no smoke, nothing got hot and the protection relay activated after a couple seconds. So all good! I connected a loose speaker and a function generator and fired up again.

Nothing, absolutely nothing. Even the relay didn't activate. So I pulled out the scope. Signal was at the input. Nothing at the output but 1V offset. Strange. Connected the second module.... idem ditto.

Ok, then signal tracing with the scope. I touch the first pin of the LM3886.... hey, this seems to move!

Ok, so the idiot writing usual mounted the LM3886 to the heatsink, then the pcb with angle brackets to the heatsink and as a last thing HE SHOULD HAVE SOLDERED THE LM3886 TO THE PCB!

I feel so stupid... Going to solder them tomorrow and see if they are OK.

HAHA! When I typed the title, I got a list of threads under the heading "Is this already being discussed here?" - Well, I hope not! I only meant that I won't greet you strangers the way my dog would.

This place is kind of intimidating, as I'm just a guitar builder & home recordist who solders only when necessary. I have tinkered with & repaired electronics, especially recapping PCBs. I have wired dozens of electric guitars & a couple houses. But I certainly don't understand how the stuff fundamentally works, I merely follow directions.

I found this site was because lately I've been searching for info on tube amps and fell into a wonderland - your member builds area. I spent a whole evening just scrolling thru all your builds, gobsmacked! DIY?!?! No, no, no! I mean, sure in the literal sense that you're making things from scratch. But, I see predominantly professional quality work here. Makes no difference whether you sell it. Indeed, the best work is hard to sell, because the general public aren't discerning and it's not economical to make anything all by oneself from start to finish these days. SAD to say! But, rest assured, few who work at any factory could do everyone's job there. You do. That's damn impressive!

Dear All

Today I have problem about power amplifier.

From the spec of circuit it can drive max 80 watt but the transformer that I have it max 24 VAC , 500 mA which is not reach 80 watt.

When I use this transformer it will overdrive sound if potentiometer reach max position.

How do I need to adjust the resistor it the circuit ?

Circuit refer below



Best Regard

Hello,
In the course of my sim rerun of my old circuits I was surprised when I find out that the extra transistor on ltp input found on AX series amp of Apex works well in balancing the currents and voltages of this bootstrapped CFP that I have drafted. The only problem that I found was that the lower resistor 3k3 (R14) receives about 300mW. The upper resistor 3k3 (R13) current was halved sharing with 680r (R31) tied on the collector of Q14.
AC analysis, transient response, square wave (1khz) shows good results. RC network 330p/470 tied at the legs of the ltp is optional. The scheme gives a good amount of ULGF and gain margin in exhange for dropping a few phase margin and some overshoots in the square wave test for the higher frequencies, but without it the circuit displays a fair amount of gain margin of -16 to -17dB and with about -77° of phase margin.
I actually created the pcb lay-out and thinking of revising it but I have decided to put a hold on it at the moment. I wanted to ask you if the additional extra transistor (Q14) will actually work. (without putting R14 in smoke of course 🙂). By the way it doesn't work without the current mirrors. I have simulated a few bootstrapped amps and most of them does not show a good balance of voltages on the output Re's. The lower minus rail always has an extra voltage of about 2mv higher from the upper plus rail. ( referring to measured voltages across each output re 0.22r, plus side vs minus side). And yes I am preserving the bootstrap 'ala' P3A 😉.
I have attached the ltspice files for you to check on (models included).

I appreciate any feedback. Thank You!

On sale one pair of Lundahl LL1635 SE 5mA transformers in good working and cosmetically condition.
Price would be 225EURO per pair, including shipping cost inside EU ONLY (registered mail with tracking).
Payment via PayPal preferred



Thanks
Chris

On sale three (3) pairs of Lundahl LL1671 SE 30mA transformers in good working and cosmetically condition.
Price would be 225EURO per pair, including shipping cost inside EU ONLY (registered mail with tracking).
Payment via PayPal preferred



Thanks
Chris

Hello everyone. I am designing a 3 way crossover in Xsim. The frequency is OK but the impedance response is terrible. I have tried Zobel networks without success or even much improvement. Could someone please point me in the right direction.
Also, on the frequency response traces, the system trace is higher that the bass and mid response. Surely that can't be right! The maybe but not the bass. The Xsim file is attached.
Thanks for your help.
Peter

Hi there,
I am modeling speaker crossover for bookshelf ~6L BR box with SICA 5.5 coax tuned ~67Hz, 40-50g of volume filling approx.
Already was stuck on faulty mic, faulty amp, several measurements with human (mine) error and so on. Such a simple task of measuring everything went extremely long and tedious. Maybe there are more my errors somewhere, but I cannot find them. Please correct my workflow.

Now I have everything in VituixCAD measurements done according to Mr. Kimmo Saunisto bible with REW and transferred to VituixCAD. Everything done more or less by the letter, only measurements made every 15 degrees, not 10, and only horizontal plane. It is a coax, so for these first simulations it will be enough.

The stuff which still gives me headache, from simple to more advanced:

1. Given the fact, that coax woofer part of driver which is positioned more for mids, not low notes - how much "ok-ish" is my BR volume? I want them to play as bookshelfs without subwoofer. Maybe some time I will add one if I build one I like. My taste is no subwoofer at all than cheap one. But this is topic for another conversation. My tactics was lowering the inside volume of the box from ~9,5L to ~6L, leaving everything the same. It sounds little better on smaller boxes, all the simulations and measurements made in 6L 68Hz BR box. So - is this acceptable BR tuning? It is far from perfect, but going for higher internal volume and lower tuning freq - it is outside this driver comfort zone and pretty ugly simulation curves. Doing opposite kinda defeats the purpose to have them as the only low freq sound source. Manufacturer recommends 8L 68Hz or 9L 58Hz boxes. What box size and tuning is your choice?


2. Impendance measurements and simulation. I am still building simple homemade rig for measurements with 100Ohm resistor, there is no DATS on my table, and probably there will be none in near future as my relationship with Dayton is bad ATM. So for now I am using manufacturer provided impendance curves, which probably are measured on big standard baffle with no box on the other side or any other random method. BR box adds another spike in impendance, in the tuning frequency, and, if I am right, not much in the upper range? Crossover in my simulations is ~2,5kHz, so is it safe to assume, that BR box raises impendance in the form on second spike a lot, and has very little impact in the higher frequencies, correct? Similarly with tweeter: it is closed box itself by construction, so no change depending on the woofer BR box, but does the baffle size/shape impact tweeter impendance curves? And finally: is there any tool which can MERGE manufacturer impendance curve with BR box curve? I haven't found in Vituixcad tools one, just the predicted one as in Winisd and other tools.

3. Harman "curve of preference", VituixCAD score. How acceptable Harman curve is for you personally? I have been experimenting with Vituixcad + EQ APO, soundcard as digital crossover, with pretty interesting results. I screenshoted them at 30 degree listening angle, as 20-40 degree shows smoothest SPL curve, highest score, also sounds most natural while listening
3.1) Manufacturer suggested crossover, for unknown baffle, 9L, 58Hz tuned box. Mine is ~6,2L, ~68Hz. Completely unbearable, too shouty, but not outright bad. You can find similarly tuned small speakers with "HiFi curve" in ASR reviews or in some showrooms. Probably with simple 3-way EQ you could make it even listenable. All the other crossover came from this one. Note not so quickly dropping woofer response up crossover frequency:

3.5) Crossover with best score (without notch filter). Very listenable Probably one to buy components for. 3-order LP on woofer too now. That extra 1Ohm resistor on tweeter makes response smoother, but I doubt that to the level you can hear difference. Pleasant sound, realistic vocals, bit too sharp on the 5-10kHz range on some sounds, don't know exactly where, but not annoying:

3.6) Also with series notch. At the cost of 3 extra components - even smoother response and +0,05 preference rating score.


The other crossover variants are pretty much the same story: even the pretty ugly one can easy score 5,5+, which is unrealistic, so I need to checkbox target curve to get realistic sore how good it is. Which ones to use:
Full space or Constant DI?
SL_ON? SL_LW? SL_PIR? SL_SP?

Which scoring ASR reviewer use? Want to compare my creation to objective tests of other speakers.

My goal is to have pleasant sounding speaker - this SICA woofer has a good timbre, so it is a good building block, want to squeeze most from it. Also it has to be psychoacoustically correct, it will be for some time my main speaker on my desk, my head has to be clear after hour, two, three hours listening in background levels, also several songs per day at louder levels. Probably Harman curve is a good place to start, correct?

4. Tried to simulate all orders of crossovers, the ones that produce workable curves are: 3 order on tweeter and 2 or 3 on woofer. Only two combinations. The question is simple - if we have VituixCAD, most of the answers about the correctness of slopes etc. are answered in what simulation shows? There is no rule to make it symetric-assymetric? Whatever works, right? Have no idea how to read impedance bumps and that they mean and where they are ok, and where they are not. Only understand, that there is no BR bump in my simulation, already asked about it. So, besides that, are my simulations more or less correct?

Thank you for your patience! All the opinions and facts are welcome. I am now in the level where the more I am going into DIY audio, the more I understand that I suck.

I'm curious why so many tweeters? They are connected in parallel with a 10uF and a .22uF cap and three resistors. The tweeters measure 6 ohms and the 10" woofer 7 ohms.

The transistors I offer here were bought in Germany around 1990 all are ESD packed.

100 pieces 2N3819 N JFET (high gain) Motorola TO-18-3, # 2.50€/ piece good for ACA as input Fet.

100 pieces 2N4393 N Jfet Siliconix TO-18-3 # 3.60€/ piece 150 pieces 2N4393 N Jfet Philips TO-18-3 # 3.60€/ piece

200 pieces 2N5459 N Jfet Motorola # 0.30€/ piece 300 pieces 2N5462 P Jfet Motorola # 0.40€/ piece

The Minimum order is 50 pieces

Worldwide Shipping from Finland. PayPal is accepted, the buyer pays the additional PayPal fees of 4%. PayPal friend shipping the 4% is waived, I still recommend shipping with tracking. The shipping costs can vary depending on the country. The shipping costs for the EU are 9€ as standard without tracking (PayPal friend) or 19€ by registered mail up to 100gr. Outside the EU it may vary by country. If you are interested send me a PM.

Here are schematics BOM and gerbers of the amp described in https://www.diyaudio.com/community/threads/200w-mosfet-cfa-amp.243481/page-75#post-6000469
Damir

R20 and R24 in the amp are there for overcurrent protection, but used value is a bit to high, better use 1.5k instead 6.8k.