Hello everyone,

After having received my XT25TG30 tweeters and Monacor WG300 waveguides, I started thinking about how to put the two together. I figured that an adapter flange would be the nicest way to do this, so I took my tweeters apart, measured them, and drew a flange in Freecad. I have attached two views of this flange.

Because the unit cost of CNC manufactured things goes down as numbers increase, I was wondering if more people than just me would like to have such a flange. If so, I could try to find a manufacturer and initiate a group buy.

Please do not PM me, but reply to this thread. Also, if you happen to know a manufacturer with good prices (preferably in the EU), let me know!

Cheers!

The guy that I’ve already repaired 2 of these amps for has another one .

The 3rd amp he has never had it repaired .

He bought a cheap oscilloscope off eBay to set the gains on these amps

He had the amp powered on and touched the positive lead to the posit r speaker terminal and then went to touch the ground lead to the negative speaker terminal and as soon as he did it blew the outputs .

What would cause the amp to blow the outputs ?
Also is there a way of avoiding this in the future if he uses the scope again to set the gains like level matching

hello, can you help me choose? .
I would like to buy a sound card in the second-hand market to save money.
its use is twofold:
microphone speaker measurements is the first function.
when I am not taking measurements its function is that of the DAC converter connected to the digital outputs of an audio player without a computer (I would also like to try the DSP to equalize). consequently the outputs of the sound card will go to a pair of speakers.
I would like a good quality of mic preamps, DACs and ADCs.
I don't want to penalize the sound card for prioritizing the type of connection that goes to the computer (USB, firewire, Thunderbolt).
besides USB2 I have a PCMCIA and expresscard port. i can always buy a converter
Hello and thanks

"Call My Name " CD will make its first North American debut at CAF 2022. ​

$25 per copy​

The composer and Recording engineer : Alban Sautour
https://www.discogs.com/fr/artist/746262-Alban-Sautour

Hello, People.

I am making a hybrid headphone amplifier, for 60-600ohm headphones, using subminiature tubes with mu of 25 (planning to use "real" grounded grid amp), followed by solid state output stage (impedance multiplier circuit with LT1206 opamps).

While 600ohm headphones make use of the extra voltage gain, 60ohm ones are reaching high levels already with output from DAP I am using, at 60% of volume.

While I am still waiting for various parts to be delivered, I experimented with the "inverted triode" circuit, which has gain of approx 1/mu. It worked, and I figured out I could use it as "attentuator stage" after grounded grid stage for low impedance loads. (A switch would be used to select "Grounded grid -> IMC" or "Grounded grid -> inverted triode -> IMC".

I would like to use the same heater PSU for both grounded grid and inverted triode, which is elevated to 1/4 of B+.

But does the same principum of cathode - heater voltage apply to inverted triode, or would it now be heater - grid voltage?

Thanks in advance.

I’ve simulated in WinISD a 11 liter speaker box with a SB acoustics sb15sfcr39-4 and a passive radiator similar to the woofer but without the magnet, it has exactly the same Sd and Xmax.
I’ve readed in many sites that for a 8” woofer do you need two 8” passive radiator but in my simulation i get better result with only one passive radiator, is this possible?

Hi experts!

Being a novis in amplifier repairs I just have to say this forum is absolutely fantastic! This is my first post ever but I have spent numerous hours to try and learn from the best. Last year I built an F6. That was so much fun and I learned a lot. Anyway, i’ve been working on an old Nad 705 amplifier that has DC voltage on the left channel and this causes the amplifier to go into protective mode and the speaker relays to open.

Right channel is ok.
I have tried to illustrate the situation on the schematic of the left channel. The blue lines indicates +8.9v to +10v. On the other channel the voltages are as the schematic shows. Between +1.2v and -1v

Is there someone that have the knowledge to point me in a direction to where the DC is coming from I would be so thankful since I’m running out of options over here 🙂
I have tested all transistors Q101,Q103,Q105,Q107,Q109,Q111,Q113,Q115 with a multimeter and a "T7 Multi function tester". Tested all resistors in this area and checked the caps for shortages (in circuit)

I have replaced C123 just to be sure.

No visual indications of heat or other distress on PCB or components.

Should i maybe replace all electrolytic caps?

Enclosing the service manual for the 705 for reference
I also found this thread from 2020 explaining almost the exact issue I have just with little higher dc voltage.
https://www.diyaudio.com/community/threads/nad-705-in-protection.356159/

I am using a light bulb current limiter when taking voltage measurements

Best regards,

Daniel E

Hi,

I am new here, trying to post a thread and saved it as a draft. However, returning to it at a later point, I cannot find where I could restore or find the saved draft. When posting a new thread I only see the option to either "Save draft" or "Delete draft".

Where may I find my saved drafts then?

Thanks in advance and kind Regards,
Martin

September 29, 1935, Ferriday, Louisiana—October 28, 2022, Nesbit, Mississippi

Which amplifier would you choose between Crown XLI 1500 and Behringer KM 1700?
Crown XLI 1500 delivers the power stated by the manufacturer and also has some more power reserve.
Behringer KM 1700 specifications only mention a max power rating (peak) and Behringer states that the expected continous power rating should be about half the declared max power rating, so one never knows for sure exactly how much power can deliver continuously into the given load.
Construction wise, Crown XLI 1500 seems to be a class A amplifier with chinese made toroidal transformer (Guangdong NRE Technology) and 4 capacitors of 63V/10000 uF.
Behringer KM 1700 is declared to be a class H amplifier and, as far as I know, it may use the same Chinese suplier for the toroidal transformer (Guangdong NRE Technology) and use 4 capacitors of 63V/10000uF also.
Is there any room for modifications on any of these two amplifiers to improve their performance and reliability?
Thank you kindly!

Some motor pulley for sale. Refer to the attached drawing for pulley dimension.

Since my shop requires a min. order of 50 pcs and I only need around 10 so there will be 40 pcs available.

$19 each, worldwide shipping included (FYI, I pay $10 each)

For sale is the originalTeflon PCB for Erno Borbely’s EB-320 Phono preamp.
$100 + shipping PP-F&F

I´ve got a Consonance preamplifier without display module.
Someone has detailed information such as make and model or replacement.

Best regards

Edgard

Since the beginning of Tekton's new array/matrix drivers, using 6 tweeters as mid surround 1 tweeter, there were alot of people discarding this as gimmick/insanity.
I was one of them. And now I have a Perfect Set at home, I can hear/understand the logic behind it.

The mid is truly one of the fastest I've heard. And the imaging (governed by the mid+high) is unbelievable. Its slightly less solid than the best 5 figures fullranger (heard from audio show, I never own them), but is way better than a traditional 2/2.5/3 ways setup.
That's also enhanced by the fact that it can be used with SET tube amp.

If anyone who have heard/auditioned the Tekton Perfect Set (or other tekton multi array models), are there any equivalent speakers out there, custom/manufacture/DIY?

Selling 1x pair of Bisesik output transformers for DAC

Version with 2 primary coils and 1 secondary coil
Turns ratio is 1:22


Asking 75€/pair, ex worldwide shipping

Hello Friends

I lik ethe dimentionso fthis subwoofer below

https://www.alderwoodspeakers.com.au/collections/subwoofers/products/atlas-pro

how to make in DIY
TAng BAnd W8-740P 8 2 drivers and peerless XLS 10 2 nos with me
but dont know how to make this kind of cardiods.



regards
anand shah

Hey Gents, I'm really enjoying the community here reading the many posts. I now have a Marantz SC-11S1 Preamp, and what a fine piece of gear it is.

Having a look, it's first-rate all the way. Highly documented issue, how/why in the world did Marantz swap the XLR pins 2>3, with 3 being hot. I got this beast home, started testing - no magical sound - until I started reading. I modified my cables to accommodate pin-3 being hot, and sure enough magical sound..

It's a bit of a disappointment I have now a 'special' unit requiring special XLR interconnects.. It's not the end of the world, quick mod, but really not free to use any old cable.

And motivations behind it? Marantz to Marantz would work just fine, in phase, pin-3 to pin-3, but start hooking up non-Marantz or XLR>RCA cables, you're listening to inverted phase and it's not usually magical. What a way to throw off buyers. It's also kind of interesting their bi-amp capability, where they propose 2 preamps with 2 power amps, great way to move a lot of expensive boxes!

I am thinking of replacing the internal signal wire to silver, I've attached the service manual and wondering if anyone might have any comment. I've ordered some JST EH style connectors and my plan is to make the internal interconnects as a quick replace / swap - no solder, etc. I'm zoning in on J102, and Tone J601 / J602 - Thinking of leaving the phono alone, as I can't foresee any phono use. What do you guys think? see anything I'm missing, or opinions?

Hi,
I plan to build a project related to a (long) FIR filter implementation [SPDIF In -> DSP for FIR filtering -> SPDIF Out that will feed a separated DAC chip].

Maybe the FreeDSP boards using the ADAU1701 could be a solution, but I have read in this thread, post#30, as a reply to FIR filter calculation, that:

ADAU1701 works with Rephase out of the box so to speak, limited amount of taps available though <500.

Click to expand...

and it is unclear if the 500 Taps limit is due to Rephase, to the ADAU1701 or to the FreeDSP boards ??

I don't plan to work with Rephase, but if the ADAU1701 cannot perform more than 500 Taps in a FIR Filtering, I need to know and identify a more powerful DSP.

Thank you for your reply,

Hi,
By reading the documentation on the FreeDSP All-in-one board, I see the pinout of the Arduino connector, fig.22:


I am familiar with the Arduino boards, and unless I miss something, I know all these pins except "WP" : the I2C bus (SDA,SCL), +5V, GND, are known, Reset can probably be picked up somewhere on the Arduino, but what is the WP pin ?

Thanks

Is it possible? Is it feasible?

I am looking for a replacement good quality potentiometer for my modded TDA7297 amp. Must fit on the original board and 50K resistence. I am looking at this on ebay https://www.ebay.com/itm/161972882607?hash=item25b6560caf:g:GB4AAOSwuAVWuVcJ&amdata=enc:AQAHAAAAsIP1zNYVqx9GEzhSgKCnsy7nJIR7jVskGQDCqmI8Ebsbw0SPN3wyQkVG18nTiKpK7L2FDcE6o90SG50+RUgAxCDFzye/w31yigA0BstGB2KemDgxzJeiw78ZvDbfh101vwoWcLYc/G8lELXo3pDB4D1wvUfigvFkNv5glpaERRNIlZ6MO0VWAv0BwOhr0tHQYZjfIInAa2E+1llqj+wZjs5gJOnOj9hOoBn0eIM2sxa6|tkp:Bk9SR4j0qKGFYQ I would prefer a single pot with a good quality, 1. would the pot above work? 2. recommend another of perhaps better quality ?

thanks

Looking to sell my GSG Full Marty (classic design) 21" B&C Subs. Finished in 3 coats of black Duratex. with Speakon connectors. Drivers are like new. Very little theater time (plenty of music though).

Asking $old for the pair.


Removed Behringer amp from the listing.

Also have two Stereo Integrity SQL-12 D2 subs in like new condition. Currently installed in Denovo 1 cuft MDF boxes finished in Duratex with Speakons. Have original boxes. Sold with the enclosures, $sold without. No shipping on the Sub/enclosure but would ship the Subs in original shipping boxes at buyers expense.

Local pickup on the subwoofers in Southwest Missouri for the Martys and SQL in the enclosures. For a serious buyer with cash in hand I can meet within a reasonable distance of Springfield MO.

Gang,

Asked Linear Systems and no response.

Anyone know what to do with the SS pins (are they tied together, I would imagine so will test) on the LSK389/489 SOIC packages?

I use these in a simple buffer at IDSS on a +/-6V system on a guitar pedal. Yay I know over doing it is my specialty 🙂

Do I ground these, -V, +V or just ignore them?

Thanks,
Gordon

Have a set of PSU1 designed for Miro AD1862 dac. Output +/-5V and +/-12V. Originally designed with 78xx and 79xx regulator ICs, have replaced them with LT1963 and LT3015. Bought from a fellow member here but have not put it to use. Caps are all Nippon Chemi Con with wima bypass. Schottky diodes. 75usd inclusive of shipping worldwide.

I've played a bit with Xsim just with dummy drivers, as I don't have concrete measurements. I then made diagrams of different 2-way speakers to see what the components do and the different correction notch that people use. I am aware that the curve I get in Xsim is not the curve the speaker gets as I do not take into account the driver's characteristics. But playing with it has given me a lot of insight I didn't have before.

Often the tweeter has a higher sensitivity than the bass and needs attenuation. I see that some have the resistor before the XO itself and others have it after. But will it depend on the individual situation whether one or the other is an advantage. A filter is shown here. I've put the resistance both before and after the 3rd order filter, to see what it does if it's on "Value" or "short", that's a smart function in Xsim, so I can see the difference in the curves in Xsim.

But is it for impedance reasons that you do one versus the other or why?

I am contemplating building a system for "light" PA. For smaller events, indoors, etc I observe that a well-designed vented system is not really being pushed anywhere near its limits.
But that system might also be working for 6 hours straight.

Assume a good-quality 12" PA woofer (with 2.5" VC) and 1" CD/horn, along with 18" subs (with 3" VC) in a 4 cu ft cabinet. Put them in sealed cabinets and play for hours on end.

Around what wattages will these motors start to heat up enough to be a problem?

Will an aluminum panel or fin radiator inset into the cabinet wall achieve any useful heat transfer?

Hello, do anyone have ELECTRO VOICE ZLX12P INPUT BOARD schematic ?

Power supply diagram it is available online but power supply is working fine, on mine there is no display and no controll at all, only backlight

Thanks a lot.

I am planning to use a mkV for my crossover and have downloaded the manual. The manual is specific about not shorting the neg out to ground like many diff out systems suggest when driving a SE input. So my question is should I add a Diff->SE converter on the output of the mkV or just use the pos/gnd as the input. The mkV uses the Sabre 2 ESS DAC's which I thought had more distortion if you only used one leg of the output. Conversely, at these performance levels, building a diff->SE converter may cause just as much degradation. Suggestions?

Have a ton of dayton bass drivers that need to be used. Hence option to go isobaric
Driver spec is 8 ohm, 85db.
For each cabinet, if I side mount two clamshell per side (4 groups, 8 bass drivers per cab) what sensitivity wd I get? Wd imagine parallel twice and series once to bring it to 4ohm.

I have fairly long, 20 foot, lengths of interconnects to my amplifiers and relatively high, 97dB, efficiency speakers so I was intrigued by the circuit. I built it as much as an excercise as something that could realistically surpass my present preamp. Imagine my shock, as a diehard Tube Head when I auditioned the finished product and found it to be nearly a match for my far more expensive (parts cost) 76 Line Stage. It's so amazingly neutral and tonally balanced from bottom to top with the ability to convey authoritative bass and delicate treble.

My 76 Line Stage is still slightly better and this little wonder is better off with someone who will use it daily. Keep in mind it is totally passive, just a volume control, a switch for the two inputs, and the low voltage elctronic buffer that makes the magic. It is not recommended for those with less than highly efficient or difficult to drive speakers.

The build includes Clarity CSA output capacitors, PTFE insulated wiring, Vampire CmHex RCA's, and a 100k PEC KKA series pot. Included is the way above average Meanwell 24 Volt SMPS power supply and a custom high frequency filter for it (the small PCB shown). Link to my all DIY system https://cgi.audioasylum.com/systems/12417.html

My cost of parts is $330 including the nice but not lovely Hammond box and I would like to get $325 including shipping to the lower 48. Payment is by US Postal Money Order only.

Here is a version of Mr. Pass M2 amp with 2SK /2SJ fets.

resistors and some caps are smd 1210 .

if anyone wants i can share eagle files / gerbers.

Here for sell a very rare Goto Unit system located in Italy. It is four ways horn system. Starting from the tweeters they are SG-16 BL , the mid-high are SG-370 with the original SG-600B horns, the mid-low are SG-505 DX with original SG-150B horns. They are state of the art horn drivers, very heavy, and big. Paired with those drivers there are the basshorns they are made of plywood on Goto Unit design with two 15" RCF woofers each. It is possible to buy only the three ways Goto. Asked price €. 12.000

for sale is a Lampucera dac, by Lampizator, you can see all information here: http://www.lampizator.eu/lampizator/LAMPUCERA/CD DAC Lampucera lampizator.html with three super regulator voltage and transformer. The case is pretty basic. €.70 plus shipping

Do you know where I can find a list of Tannoy home speakers made in the 60s?

This last weekend I heard a pair of mid 60s Tannoys that left me speechless. The guy was playing a Jadis integrated amp, low power and he played a CD of female singers.

It floored me.

Now then, I've been looking into a high efficiency speaker and those Tannoys would fit the bill but I have no clue how much they would cost. The fellow said the name but I plum forget. Of course he won't sell those, they are his private stash... I asked.

The speakers were homely... walnut, old style burlap like grill. a little over 2 feet tall, about 1 1/2 wide and foot deep. The grill came out with a brass key! The baffle was finished with cork. The drivers were coax... 10 or 12 inch with a tweeter in the middle. I don't remember if it was ported.

Just standing six feet in front of them, in a old office in an old building filled with all kinds of sumptuous components in various states of repair ( High End repair shop in West LA ), I felt like dancing. These are seriously good sounding speakers.

They sounded LIKE MUSIC.

I wonder if I can afford them.. but first, I need to figure out what they're called. If I can find on online list I can likely find them, if not I'll have to call that fellow again.

I have 26 pieces Caddock MP915-0.20R-1% thick film resistors without use .
I’m asking for 26pieces €40.

Power Rating: 15W with Heatsink / without Heatsink 1,25W

• Product Range: CADDOCK - MP915 Series
• Resistance: 0.20ohm
• Resistance Tolerance: ± 1%
• Resistor Case Style: TO-126
• Resistor Element Material: Metal Film
• SVHC: 03-Aug-2001

Price + PayPal 4% + register shipping expenses.

Shipping form Finland

Rgds
Finwbu

Hello guys! I built the Mullard 3-3 according to the original Mullard schematic.

I have 2 problems:
The R15 resistor (after the EZ81) gets very hot, a 2W type 330Ohm isn't lasting very long. a 5W 330Ohm resistor gets very hot.
Second and frightening problem: The mains transformer is vibrating. This vibrations causes hum to hear coming from the speakers and you can feel the hum!!
Caused by too much current flow? The amp sound great but you can hear the mains transformer humming and vibrating.

I use a transformer kit from primary windings (UK).
I use this mains transformer : https://primarywindings.com/product/mullard-5-10-mono-mains-transformer/

I checked all over the net and everyone is out of stock on these outputs .

The only one that shows stock is overseas and I dont really trust ordering parts from overseas .

Wondering if anyone knows a good replacement for these ?

FDA59N30

I am trying to understand the difference, if any, of cabinet vibration at the 1st modes (first breathing modes of loudspeaker cabinet resonance) if it is within the pressure frequency region. For a smaller cabinet the frequency band-width where sound acts in pressure mode is wider. So if the first resonant modes fall in this region is more of the energy (back wave of driver) transferred to the vibrating cabinet walls than if this first resonance was further up and passed the pressure zone? I guess this question would be similar to the concept Room Gain/Car Gain and if there is an effect caused by the walls/doors/panels of the room/car vibrating at frequencies where room/car gain comes into play. What would the consequences be?

Now to complicate things what if we also have a port/passive radiator present (open window, or car door to the outside).

What I have read is that if a port is present on a cabinet, lets say tuned to 50hz, there is only a depressurisation of the cabinet at frequencies up to twice the tuning frequency. So past 100hz (and if the loudspeaker is small enough) pressure is maintained above said frequency. So if a cabinet had its first mode below the 100hz, lets say 80hz, it could affect the port output. I would assume it would act like another mass spring system (another port)? Would the presence of the port mitigate the cabinet vibration so that it is less prevalent than if no port was present?


Any insights would be helpful.

Hi All,
Stumbled across this on youtube and thought to ask what everyone thinks of the design? Schematic and details
Login to view embedded media
I may have got a little excited and ordered some 6n13s tubes... And I have to say thats a gloriously pretty build!

It's almost fashionable to complain about wearing a mask. But the fact is, I haven't had a singe instance of cold or flu symptoms since Covid appeared and I started wearing a mask in public places. That is unprecendented.
If I had previously known this would be the case, I would have started wearing one much earlier.

I’ve been thinking about new subs for my modest townhouse home theatre and came across the SVS 3000 micro. By all accounts a fantastic sub woofer, producing deep clean bass. All from <11 cubed with dual opposed 8” woofers!
But it comes at a steep fiscal cost!

So, I was wondering if anyone knew of (or could help with) a design that is modest in size, deep in extension and compromised in maximum output?

I don’t need 115dB of 20hz output, I live in a townhouse and share a wall with a neighbour (like a lot of people do!), but I do want clean articulate bass with a bit of rumble on demand for movies and music.

I don’t know where to begin in designing this ( what T/S parameters to look for) so if anyone could even suggest drivers or specs to search for it’d be appreciated!

Design goal:
16” cubed enclosure (external)
<25hz response
Reasonable SPL & power handling ability
Affordable

I’d love to hear your thoughts or suggestions?

What's a halfway decent board that has these specs?

1. Remote control (for gain/volume)
2. RCA or 3.5mm input
3. 50W x 50W'ish
4. Accepts 14AWG speaker wire or clips

It'll be used for non-critical listening.
Hoping to find something in the <$35 range.

Hi all,

A simple question for discussion. Mainly looking for measurements or some links that explain it technically, but happy to hear user experience too:

Does the driver placement relative to the port in a bass reflex enclosure matter?

To further clarify, I'm wondering if the vent pole of a driver is near the entrance aperture of the port internally, if it matters, or if it needs to be as far away on the port side, or far away opposite the port side (the most indirect pathway for airflow) and if so, why? If it does have a negative impact, is it only on paper or does it manifest audibly? Let's assume the port is sufficiently large to not create noise from excessive air velocities, say, over 18 meters per second or similar for argument. Lastly, does it change with the frequency (ie, does it matter or is it different from say 17hz vs 25hz just as examples)?

Very best,

(First I'd like to re-post to the Lounge a highly relevant 🙄 self-test from https://www.diyaudio.com/community/...e-crossfeed-stereo-sound.391630/#post-7160131 )

Everyone please join a fun psychoacoustics experiment.

While listening to music:
o Close both eyes, sound becomes clearer, fuller, more delineated and organic (i.e. "BETTER"), in particular bass sounds louder; YES/NO?
o Open both eyes, instruments (individual or section) are more precisely imaged/located (especially how far from you), compared to eyes-closed; YES/NO?
(Now the fun part)
o Close left eye and open right eye, the left half soundstage is more precise, but the right half sounds BETTER; YES/NO? Of course
o Close right eye and open left eye, the right half soundstage is more precise, but the left half sounds BETTER. YES/NO?
Please respond with your results!

Now, if you agree with me (YES/YES/YES/YES), the question is WHY? (My hypothesis/explanation to be posted later.)

As for relevance, any listening test (including by oneself) must ensure the testers are consistent eye-wise. And there's a natural extension to A-B testing, or rather L-R testing!

I'm a fan of these beefy radios. I've discovered that the woofers frequently fail at even moderate volume when playing bass notes. Maybe age, maybe abuse?

The speakers crack up and distort. Cones look OK and reproduce fine at low volume.

Is there any repair?

I'm looking for a drop-in replacement on Parts Express, etc. Their customer service said very unlikely and suggest I go thru their options and modify mounting holes, etc. as needed.

Any experience on this forum?

dizmayed

Hallo ,
i have 2 output transformers from ROWE AMI MM4
I do not know how to get sekundar output

this color ist:
Black
brown-white
white
yellow
green
green-white
green-yellow

I had no problem finding a service manual and parts list for an SME 3009 S2 TA, but MAN, seems like SME hides this info for the Series V like Apple does its OS source code.

Again, SERVICE/parts manual.

Anyone?

Thanks.

Norm

I'm lazy , so there are excerpts from my correspondence on Tannoy Yahoo group; all quotes - Mighty ZM

I'm putting this here as future reference for some other desperate Tanner ; I must admit ( or I'm just boasting ) - I'm always having serius backup for all things speakers - from Aleksandar RAAL ....... even if I'm always stubborn and I'm bugging him only post hoc ..... to be sure that I didn't blew something

K3809 - cloth surround impregnation solvent ?

as I wrote - pair of K3809

cloth surround , no back cone ribs
Fs is high - around 70Hz on both drivers
I contacted Tannoy Support , but they can't help - all they can recommend is
reconing , which is out of possibility , counting on fact that drivers are in
excellent condition and just slightly used (well - same as they aren't used at
all )

so - anyone having real life experience , regarding solvent for surround
impregnation ?

whatever , guy at Hasling Audio Systems Denmark is doing exactly the same for SH
Altec's , so I think same is possible for Tanns

TIA

Click to expand...

Tnx for reply ;

There is no particular info on Altec related link , but point was that planned
procedure was implemented ...... I sent e-mail to Danish guy , asking for his
recipe , if nothing else , as starting point .

Whatever - K3808 (3809) are having impregnated cloth surround , not paper ;
that's visible on many pictures on net , and "cloth surround" is having exactly
that name in related info

In any case , if I succeed in "operation" , I'll share my findings

Click to expand...

of course - "Danish guy " wasn't prepared to share his recipe ; I don't blame him 😉
that's why I'm sharing mine

besides Sam R's problem with teared surround ......... and strictly speaking of hardened cloth surround - I'm stubborn and there is no way I'm going to change them .....

I would go to generic soft (probably acquired from Sonido guys in Hungary )
cloth surround , but will ever never invest money in new cones or - God forbid!
- neoprene surrounds 😉

I remember some guys at Diyaudio speaking of
2-Butoxyethanol - Wikipedia, the free encyclopedia
so I plan to start with that

Click to expand...

Hardened cloth surround problem solved !!
soaking both sides of surround , using small brush , with plain Ethanol 95-96% ,
brought Fs from 71Hz to 29Hz .

I'm expecting that Fs will rise to spec. 35Hz , when solvent evaporate
That's what we are calling just Pure Alcohol , and you can buy it in every
drugstore.
So much speaking of recone and surround replacement 😉

Click to expand...

I'll keep you informed , of course ;

even in case that Fs start rising again , I'll just repeat procedure , removing
old impregnation as much I can , and brush new tacky layer above it

then it will permanent solution

no damage , certainly ;

I'll post few pics in few days , after having definitive conclusion about
longevity of cure

Click to expand...

Update : after 24h rest and solvent evaporated - two steps forward , one step back 😉

steps forward are :
1 - impregnate is not brittle and cracked (inducing noise , especially
detectable at Fs)
2 - everything looks just nice , almost as new

step back - Fs is back on 71Hz 😉)

whatever , I'll proceed with more cleaning of old impregnate , and then try to
seal it with tacky surround goo , which will (hopefully) prevent repeated
hardening

will keep you informed

Click to expand...

OK

K3809 - cloth surround impregnation solvent ; hardened cloth surround - high Fs
- issue SOLVED

procedure finished and confirmed
after 24h (and more ) of solvents evaporating , Fs is still good : 33-35Hz

RECIPE

what you need :

1.small brush , semi hard m ~8mm wide , same as kids are using for painting in
school
2.Ethanol 95% (pure alcohol)
3.Acetone with oil ( nothing else than nail polish remover )
4.mouse glue (yes , that organic everlasting sticky goo)
5.Vaseline
6.cotton cloth ( old T shirt or whatever)

brush - buy it anywhere , mouse glue - anywhere , everything else - nearest drugstore

important to say - surround was originally threated from upper side , mostly ;

just slight residue of original rubbery impregnate is visible from bottom side
of surround

procedure for upper side of surround:

using brush - from upper side - soak surround with ethanol ; it's best to soak
it in parcels of 10cm , then rub it with same brush ; whenever you fill brush
with residue , wipe it on cloth

repeat procedure until you make two full circles (so entire surround perimeter
is twice treated)

move to second speaker ,same procedure , again two circles ;

repeat same soak-rub-wipe-soak-rub-wipe procedure on both speakers , until you can see clear fabric of cloth , without any trace of rubber

it's fun , but only if you have some muzak and coffee 😉

after few steps in procedure you'll see what's happening ; if you think that
you'll gain anything with another soak-rub-wipe circle , just do it

leave speakers 12h , to let Ethanol to evaporate

now - put some mouse glue on small (coffee cup) plate , add acetone and dissolve it to something liquid as milk

using brush - put that mixture on upper side of surround ; if you see that your
mixture on plate is going firmer , add acetone and mix ; when you treat entire
surround , take just acetone with brush and treat entire ( already impregnated )
area with it , to make it more uniform

leave it for 12h

now - bottom side of surround :

soak brush in acetone , rub it firmly in Vaseline , then put that mixture on
entire bottom side area ; goal is to have tiny layer of vaseline on bottom side

leave it 12h

measure Fs

easiest way of measuring Fs - use sine signal generator with 50R output
impedance , connect it to bass terminals , put CRO probes on terminals

sweep frequency from 100Hz down ; when you see biggest sine amplitude , there is Fs

another possibility for measuring - instead of sig gene - use Sig Jenny program
( wave gene with counter ) , sound card to small amp , amp to bass terminals ,
AC voltmeter to terminals

put few volts of sine to bass , sweep from 100Hz down , when you see biggest
reading on Vac meter , that is it

mine are at 31 and 33 Hz , I'm not loosing sleep because of using mouse glue and
vaseline on piece of cloth 😉

Click to expand...

mouse glue
look : http://images.google.com/search?as_...=&biw=1680&bih=910&sei=66vYUKOSNouN0wXdlICoAw

Click to expand...

then one guy is saying that Mouse Glue is forbidden in some EU countries ; my reply :

in that case - just buy softest surround impregnation goop ; easy to do on line
, if living in Europe

unfortunately - Serbia , where I'm living - somehow isn't in Europe , so I'm
Paypal-less 😉

that means that I'm just lazy to chase soft surround impregnation goop from
Europe , taking in account that there is no domestic one

Click to expand...

then guy asked where to search for surround impregnation goop ;

my reply :

sorry - just google ;
search for something like this : Speaker Repair Adhesive, Sealer, Cloth Surrounds, Foam Surrunds, MI-1291

but , it's wise to buy only after confirmation from seller that really soft
thing is in question

Zen Mod

Click to expand...

then guy asked for difference sound-wise , pre and post procedure ; my reply :

sound-wise - taking in account that my pair is most mint pair I ever had
opportunity to even see (except surround condition - most probably as result of
no-usage for all long years ), I'm eager to say that they're sounding just as
proper pair of K3809 😉

right now being in stage of preparation of making boxes for them , I'm having
fresh experience just listening them in bafle-less iteration ; even like that ,
there is proper difference in bass , comparing to prior (surround treatment )
performance

whatever , fact that plain and common Ethanol is sufficiently good as solvent
for old impregnation , was nice surprise ....

Zen Mod

Click to expand...

I hope you enjoyed little story

In case that I remember to get cam to my workshop tomorrow , I'll make few pics and put it here , along with few pics of same drivers prior to fun procedure

Hello
greetings can anyone help me out i am trying to make this simple
tone control as i am not a pcb designer can this tone control be
made on a double sided pcb with lots of ground plane and SMD
components.I have made it on a dot pcb with LM4562 can it be bettered
with OPA1612 IC . Sorry for asking so many questions
warm regards
Andrew😕

64 step relay attenuator using an ADC0804 8-bit ADC.

I am not using the 2 lowest lsb's.

The biggest problem when using something like an ADC0804 together with relays for attenuation purposes is that you can get situations where one relay releases(breaks) before other relays has time to operate(make). This is especially a problem with 100000>011111 transitions where you risk having no attenuation if the first relay turns off before the 5 other relays activates.

The solution is to implement a make before break action. This is usually done by having a microcontroller control all the relays which makes it easy to insert delays that give you the desired make before break action.

However, what if we could use the characteristics of the relays to get the same desired make before break action?

Looking at the datasheet for the excellent low signal relay Omron G6K-2P-Y it is shown that operate and release times are identical at 3mS MAX with 1.4mS as a typical value. Bummer. However, when designing with relays it is good practice to include a flyback diode to protect the BJT or FET used for switching on/off the relay. The downside to this is that you get longer release times, usually on the order of 5+ mS.

In this case the longer release times should in theory give you enough time delay between the making and breaking of the relays to avoid the no attenuation situation.

This is what I have tried to implement here.

The pot should be wired so that when it is turned fully ccw, you get the full voltage to the ADC which makes all the relays go on and giving you full attenuation. Now as you turn the relay the voltage drops, turning on/off relays as you go. Since we have slowed down the release time due to using a flyback diode all the relays should in theory ensure you get a make before break action at all times.

Does the theory hold true in real life? I do not really know but I have convinced myself that it would work just fine.

Got too much stuff need to pare down. Pictures available on request on all items

• DIY early implementation of Purifi Amplifier build DIY post 359,360,362 or Audio science review DIY Purifi Amp Build post 183-244 and following. Pictures and documentation available on request. Asking $1,000.00 U.S including shipping in CON U.S. .
• Topping PRE90 and Topping EXT 90 like new. This is a very good preamp comparable to a Benchmark LA4 as far as sound goes. It is an excellent preamp match with the purify amplifier. Asking $800 including shipping in CON U.S.
• A pair of Selenium HM4750 SLF horns 2in throat 90 by 40 lower limit of 400 hz. I used them with BMS drivers with good success (no I do not have the BMS drivers). Asking $50.00 each buyer pays shipping.

Hello all,

Does anybody have any information on this unit? Seems to date back to the late 40's or early 50's. Meters full scale indicate 500V and 300mA. Uses 2x 83v, 4x 6L6G, 1x 6SN7 & 1x NE56. Any info appreciated.

Art

Hey all,

I have a pair of Quickie 8417 amps - the two rectifier version. It was returned and modded by Quicksilver for all other tubes (as said by previous owner), and currently fitted and biased for 6550 @ 70ma each pair.

Anyway with that huge 390uf cap after the rectifier, I pulled the parallel pair of 5AR4 and dropped in one of my DIY SS rectifiers (an empty octal base with two series UF4007 from pin 6 to 8 and another pair of series UF4007 from pin 4 to 8, and base filled with hot wax). Don't really see an improvement in sound, but I just don't like seeing those expensive 5AR4s getting tortured...anyway, there is a rather hard and noisy start up from the power transformer...looking at putting in a CL60 or CL90 on tranny primaries...or better simpler option?

Also any advice for quieting the mechanical noise from Transformers? These two amp transformers have to be the noisiest I have ever had...

Also noticed it still does not have a Chassis ground...odd that the factory didn't bother adding it... I will add either way...

Can anybody advise modern replacements for these transistors? All are dead after catastrophic failure in the voltage control amp.
The SU-V60 uses exactly the same circuitry, by the way.

EDIT - 2SA1306 NOT 1309

I'm selling

8 x 0.33 uF 600V Jupiter Copper, Paper, Wax coupling caps, 45€ each + shipping
2 x 0.1 uF 600V CuTF V-CAP, 60€ each + shipping V-Caps are SOLD!

I recently got around to fixing up a pair of Leak 600 speakers from the early ‘70’s. They had been sitting in storage for about 5 years, since I bought them, basically for the 12” sandwich woofers, which were ahead of their time. My brother had a pair in the 70’s and I was always impressed by the way they reproduced bass. Very tight and punchy for a moderate sized box (estimated 60 liters = 2 cu ft). My brother was a semi-pro drummer at the time, so he liked realistic bass. The mid-range and treble were nothing special and the way they were mounted side-by-side, stereo imaging was never their strong point. My plan was to replace the mid-range and tweeter with good modern equivalents and reconfigure the baffle to have mid-range and tweeter in a vertical line. I found that the 5” Peerless HDS P830860 drivers are a perfect fit for the existing cardboard tube mid enclosure. The old treble cut-out was blocked up flush and a new cut-out above the mid opening was made for a Vifa DT27TG-35-06. I know these drivers well and like their performance. The caps in the crossover were replaced just in case (they were over 40 years old!) and I tested the level matching with my Behringer RTA. The frequency response was flatter than with the original drivers, so no padding down of levels was necessary. Now I got a bit creative. The mid and tweeter sharing the same baffle as a 12” woofer is not an attractive idea. Usually this requires a really solid and braced baffle. In the original 2-way Leak sandwich speaker, the tweeter was mounted to the grille to isolate it from the woofer vibrations. Also the woofer magnet was tensioned up against the rear of the speaker by a treaded rod. Taken with the bituminous damped ½” plywood box, and the sandwich woofer, Leak were ahead of their time in many regards. However for the Leak 600 the threaded brace is dropped but a solid hardwood 2”x2” brace connects the baffle to the rear. In the spirit of the original idea, I wanted to partially isolate the mid and tweeter from the woofer by not mounting them to the same baffle. So glued a super-baffle with an enlarged woofer cut-out to the original chipboard baffle. The woofer mounts to the original (inside) baffle with the same mounting holes and the mid and tweeter mount to the super (outside) baffle. The two baffles are glued together by a 3 mm thick layer of adhesive damping compound (Bostik V60 glazing silicone). This is my attempt at a constrained layer damped baffle. The mounting screws for mid and tweeter do not penetrate into the inner baffle as this would provide a transmission path for unwanted woofer vibrations to affect the other drivers. The 3mm layer of silicone can be seen between the ply box and aluminium trim. New grille cloth and Velcro fixing complete the project. The level of vibration on the mid-tweeter baffle is noticeably less than on the rest of the box. I am ecstatic over the results. I consider that I have improved a flawed classic, while preserving the still excellent external cosmetic condition. The cheapo stands are modified IKEA Bekvam stools.
BEKVÄM Step stool - beech - IKEA
They are a perfect height but not they last word in rigidity. These speakers must be listened to on axis.

Hi All

So i received a pair of lovely 103.3 with the kef kube.

As you can imagine they need some servicing. Unfortunately the PSU has seen better days and would like to upgrade it, perhaps use a torodial or rcore transformer instead. The output voltage is 19.1vac at 230vac. This drops down to around 18.4vac when connected to the kube.

I would like to also upgrade the capacitors and opamps. Any suggestions for opamps?

Thanks

35x35x35cm big and 35kg of weight. Top materials and parts. Big mofo with 2,7A bias and regulated THEL AUDIO regulator power supply. The best I have heard and much better from any other psu in mofo. Big screw on KEMET capacitors. ClC psu befor reg. A truly hiend version of mofo and the sound is superb. I have build so many amps from pass, mirrand audio, hypex, symasym...... But the mofo with right preamp is the winner. The transparency is on another level. I have this in my system with Ccda 6sl7 preamp and this combo is amazing. Becose of weight I can shipp only with dpd, gls or dhl and the costs will be around 50 euro with insurance inside EU. The price for mofo would be 800 euro, or best offer.

Adam Munich and his x-ray machine.

https://www.popsci.com/diy/article/2012-04/you-built-what-portable-x-ray-machine/

https://en.everybodywiki.com/Adam_Munich

I anyone out there still using Liberty Audiosuite? I've been getting great results from it for about twenty years. Last week, I moved my equipment around,
which involved disconnecting and reconnecting a few cables and I've now managed to lose the second calibration channel. So I can't do dual channel measurements any more - there's no signal on the bottom half of the screen. Single channel measurements work OK and I could probably live with that if it weren't for the fact that I've also lost the ability to do impedance measurements, which is critical (obviously).

So I guess it's likely to be a wiring problem, but I can't figure out what I've done wrong. I'm using the Echo card with the standard Liberty mic amp. Unfortunately, there's no drawing or photograph in the manual of how to connect the mic preamp and connection box up. I've checked all my cables for continuity and everything seems fine. I've also tried many different possible combinations of wiring but the second channel remains stubbornly unresponsive.

Any ideas? I have a backup Echo card, just in case.

By the way, this problem has forced me to look at some more modern testing software. I've tried Holmresponse, which I couldn't get to work at all, REW and Arta, neither are of which are very user-friendly. It might be because I'm used to it, but I'd still take Liberty Audiosuite over any of them. 🙂

The pre-amp has three golden-plated RCA line inputs through an ELNA gold-plated selector and two RCA outputs.

• Four Philips JAN 6SN7 tubes, one SIEMENS GZ34 rectifier tube.
• Gold-plated ceramic tube bases.
• Jensen main rectifier electrolytic capacitor.
• All audio signal caps are Clarity caps and Mundorf Mcap Silver oil.
• All resistors are KIWAME and DALE.
• The volume control is a ladder 24 DALE stepped attenuator.
• Point-to-point construction.
• Aluminum 2mm chassis electrostatic painting with copper nickel-plated cover in the front panel and above.
• In general, is a HIEND preamp with the best components for all your life!

Price 2.000euros plus 50euros transportation cost in EUROP area.

Tasos Architektonidis
Athens, GREECE
demiurge30@yahoo.gr

Hello,

Is there a converter (board, module) suitable for powering symetrical DC chips from single DC power ?

thanks

B1K Nutube preamp populated board. Worked around 200h, replaced by custom version of the same preamp.

Price 100$ + paypal and shipping fees

I found the Sonido SFR200A speakers in stock at a local dealer. Since I have heard them some weeks ago at an audio show, I bought a pair. They are about the same price as a Fostex 206E but with a cast basket, wooden phase plug and AlNiCo magnet.

Before they get some proper boxes, I bought two 45 x 35 x 2 cm bamboo cutting boards. There is a 5 cm fold, so acoustically they are more like 45 * 40 cm. I routed the hole for the speaker and cut, glued and screwed on a piece of pine plank as the stand.

They are now running biamped with a Peavey FH-1 bass horn copy below ca 250 - 300 Hz. I can only compare them to my good old Beta12CX + Selenium D210Ti MLTL. I would say that the sensitivity is slightly lower on the Sonidos, but the sound is definitely better, it seems that it has even more treble extension. I need to confirm that by measurement, it may be also more like "presence" and not real HF extension. Also, the current test position is far from ideal, I need to test them further from the back wall with a matching bass cabinet below. Drums sound really amazing, the sound is very detailed, sharp and "fast".

I plan to build the Schalmei double horn with them as I do not want to stress the FR speaker below 100 Hz and have a proper low extension with a separate cabinet (most probably a small TH or Alphorn).

For sale is almost the complete active devices needed to build DIY Sony VFET amp 2016(push-pull)
1) Two pairs of Sony VFET K82/J28
2) Two pairs of TOS K2013/J313.
3) Two pairs of C4793/A1837
4) One MQ of K170/J74 (Idss=7.7mA)
5) Eight pieces of TL431
You will need two pairs of irf240/9240 to complete the active device list.

Number written on the VFETs is Vgs tested according to the 4th picture.

price US$600 for the set, shipping inclusive.

payment by PayPal “Friends and Family”
please send me a PM if interested.

Hi y'all

While setting my bias current i blew up the two output transistors of the right channel of my denon pma 2000 mk IV :-(. Yes, I know, it's a stupid mistake...

I tested both transistors - Toshiba 2SK2967 mosf n channel - and they're shorted between source and gate/drain.
I'm looking for replacements, but I'm not really well informed on what to look for.

• should I go for the same type or are there already better replacements? Are those from China on Ebay really the same, or are they copy's?
• Are there other interesting platforms to buy on than Ebay? I know mouser, but these particular toshiba's are not available... I live in Belgium.
• Do I preferably change all 4 transistors, so the left channel also?

- And, while the amp is completely on the table, are there other modifications that someone knows about that can improve sound? I know the preamp sections isn't the best...

I'm looking forward to your feedback!

Kind regards

Will

has anyone here listened,know or own a velleman K4020 MOSFET kit amplifier?

heres the link to it: http://www.qkits.com/serv/qkits/velleman/pages/K4020.asp

WHAT ARE YOUR COMMENTS ABOUT THIS AMP?

ANYONE HAS HP3580A FOR SALE

** PRICE REDUCED - 15% OFF LISTED PRICES ***

Hi,

Selling a boatload of surplus kit.

All items in Dublin and cash-on-collection most welcome, but happy to ship (preferably UK/EU) at buyer’s expense and risk. Payment via bank transfer or paypal friends/gift.

PM for further pics / details etc.

Cheers
Adrian

PS: Due to pic number limit (remaining items RCF RCF H3709 1” aluminium straight horn, Emilar EH 500 2” cast aluminium radial horns and single Emilar EE 1-2 1" ADAPTER, Renkus Heinz SSH820 2” cast aluminium horns, ZXPC 2" Throat Horn Bolt-On 18"x10"For Assorted Bolt On 2"Exit Drivers 90°x 40 and DDS CFD ENG 1-90 PRO-S 1” conical horns) in separate thread: https://www.diyaudio.com/community/...heinz-zxpc-and-dds-horns.389965/#post-7115311


(1) Pair of RCA 9458 3” phenolic/1.4” exit compression drivers with pair of NOS/uninstalled diaphragms.

These are RCA’s post-war, PM cinema compression drivers . Have the pepper-pot phase plug, I believe. On the right horn, supposedly good from circa 300 Hz to 6K. Plenty of info on the web.

This pair are UK badged and says made it in the UK, but I find that hard to believe. In excellent cosmetic condition (see pics).

Picked these up years ago (sans diapers) and managed to source 2 NOS diaphragms (in original boxes) since then. Measure 9.2 and 9.4 on my crap ohm-meter. Diapers have not been installed/used so new owner gets the very rare opportunity to hear these circa 70+ old drivers like new!

£2.2k.







(2) Renkus Heinz SSD 3301 3”/2”exit compression drivers (16 ohm) SOLD

Lots of info on web.

In excellent condition and measure 10 and 10.6 ohm.

Would make a nice pairing with the Emilar EH 500, Renkus SSH820 or ZXPC 2” horns I’m also selling (see below). Eg:

https://jelabs.blogspot.com/2018/02/altec-32a-32b-emilar-eh1210-eh800-eh500.html

https://www.diyaudio.com/community/...-home-system-pt-ii.330481/page-2#post-5811997

£150




(3) Single Altec 292a 2.88/3” phenolic/1.4” exit compression driver (16 ohm)

Picked this up years ago and had it remagged and installed with new 16 ohm diaphragm by GPA. Sat unused since then. Should be able to dig out GPA receipt.

In excellent condition and measures 10 ohms.

£300





(4) Altec 23691/414 12” 8 ohm woofers (with 210607 cones)

These are “special” Altec 414s (b’s or c’s) which were used in its 1970’s Stonehenge I speakers. Both have the original 210607 stamped cones used for the 414 and the only difference that I can tell is the dustcap has no vent in the middle.

In excellent cosmetic and operational condition and measure 6 ohms. Happy to shoot through vids of working units.

£600

IMHO, would be an ideal match with the Altec 32c horns (see below) to whistle up an Altec version of the WE 753 ala JE. See: JE Labs: Altec 753C






(5) Altec 32c (plastic) 1” exit bent horns SOLD

Based on the WE 32a horn and used in various Altec speakers, including the A8, Model 15, A8, 9849, 1221/1231. General consensus is that this is the version to have (as Altec reworked the throat length to properly account for use with 1” drivers and is less resonant than earlier metal versions).

Loads of info on the net, including:
https://electravolt.blogspot.com/2018/10/the-tale-of-three-horns-variations-of.html

https://hifihaven.org/index.php?threads/altec-2-way-build-ala-jelabs-802-32-414.3452/

Becoming quite valuable now given the attention from J-Rob and JE.

In excellent cosmetic condition.

£400







/ENDS (PART 1)

I am in the uk.

TLDR: I am trying to decide which way to go with tools.

I have used various tools in the past, but they are not very good.
But neither am I.
They were good enough for hacking up wood for garden stuff. Sheds, bases, fences, that sort of thing.

I have never had the time to work out how to do things better. Now is the time.

I do have a small garage, but I don't currently have a lot of floor space. Not quite big enough to fit an 8x4 sheet. But I am considering removing some stuff to make more floor space.
I am considering seeing if I might get rid of some things to make space. It all depends on how much space is required really.

I just got a second hand circular saw (i found my last one in a skip and I can tell why 🙂 ) But need to put more effort into making it square I think.
Bosch GKS 190. But I am not positive it is square.
I don't think my straight edge is straight 🙂

I have a half decent chop saw (bottom end makita).

I have started having a crack at the fun OB speakers to see where I need to improve.

My questions are a bit vague while I am trying to work out which way to go. If doing a half decent job will be too much money or space, I will have to accept it and try and find a place that cuts things to size.

I would like to be able to do it myself for other things like simple furniture as well.

Skill saw

My straight lines with a skill saw were not always straight. I am assuming that is my technique. Although, do better skill saws have better adjustments to get their angle dead right? Mine seems a bit vague when setting the bevel.
Also, is it actually possible to be as consistent with a circular saw as with a table saw?
I already know I need to make more space as I was over reaching, having to stand on it to cut it 🙂 stuff like that.

I also tried doing it on a folding workbench, but I think the floor is a better way to go while the bits are bigger, right?
I just need some thicker sacrificial bits underneath to allow for C Clamp space, right?
(Plus an actually straight, straight edge)

Table saw
I am thinking this is the other option.
I am also thinking I would love one.
I am also thinking I need loads of space for this.
Am I right I could roll the table saw under something for storage?
But then I also need support for the wood as I cut it, right?
I suppose the question is, how much space and money would I need?
(I think I might have to do some research into getting someone to do the cutting 🙂 )

Jigsaw.
Again, only had a cheap one which was frustrating to use.
I am thinking this is a necessary tool for driver holes.
Can I get some advice as to which way to go please?
what sort of numbers am I looking for?

I have an ok screw gun and corded drill.

Sorry it is a long one.
thanks.

I plan on building @mabat's ce360 out of wood because I have access to cnc machines and I prefer horns/waveguides out of wood 🙂

My proposed crossover is at 800hz because the directivities would match with a 15" and ce360 plus cp380m can play that low and could still extend to highs. I think I will need to go for a bass reflex box to get some bass out of this setup. I like slots so most probably I will have the 15" in its own bass reflex box with slot on the lower front side and add the ce360 waveguide as a self standing unit on top.

I have access to B&C and Beyma 15" woofers. I think 40hz tuning could work with a suitable one . I am open to suggestions, I never played woofers up to 800hz, so I do not exactly know which ones to go for. Do lighter cones have an advantage?

I plan on doing it passive, a LR 24db filter would be ok, I guess.

Any suggestions, pointers or criticisms are welcome.

ps. I have rew and dats and will measure when I build the boxes and waveguides with the drivers to finalize the crossovers.

Hi all,
Maybe anyone know the parameters T/S:

Fs,Qts,SPL,frequency response

for Altec Hollywood Dia Cone Model 600 Speakers?

https://www.ebay.com/itm/1754674053...5u95wZc5UEXkelOaZP6+CobPg=|tkp:Bk9SR4TfqI-FYQ

regards,Alex

Hi

Im looking for some advice regarding an amp I´m planning to build. I have started to gather the components and at this point I´m looking for the coupling caps, 2uf 400V. They seem hard to find and the value 2uf is higher than what I´m used to. In amp´s I´ve built earlier the value is usually 0.22uf or 0,33uf.

So, my question is; is the value in the schematic 2uf right and if so where can I find a coupling cap with this value?

Any suggestions are helpful.

Cheers!

I think the even pins would be ok. I'm quite concern with the odd ones. Thanks

It's finally finished. Nothing spectacular, but feature rich, pretty damn good sounding and fancy lookin'. Driven by a single, cheap 7.5-9V switching or linear power supply, with 5 inputs and 1 output with tape monitor , switched by small signal relays. Controlled by Apple TV compatible remote, panel operable with two independent encoders, with graphic 2.4" OLED. Attenuation done with PGA2311 running on +-5V with negative rail inverted from +5V and stabilized with -5V LDO. Firmware ported from LDR Pre MkII. Volume steps are 1dB, from 0-99dB

Why PGA2311? Because I heard Musical Fidelity M3Si which is using the similar chip for volume control, and it sounded fantastic.

All passives are SMD 1206, easy to solder even for 56 year olds like me.

Some of the features:

1. Sleep timer (1 - 255 minutes, 0 for disable). Also switches off external relay if connected, for turning off power amp for example.
2. Screen minimum brightness (0-255)
3. Screen maximum brightness (0-255). Screen dims down from max to min after Screen Saver timeout
4. Screen saver timeout
5. Channel Balance (+-20dB between channels)
6. Fully customizable input and output names
7. Fully customizable welcome message
8. Screen off time (1-255 minutes, 0 for disable)
9. Safe volume level - volume value will not be saved on power down above this value, to prevent a surprise on next power up.
10. Child lock - disable encoders and hide a remote 🙂
11. Automatic delayed power amp control, also manually switchable.

This has now been discontinued.

Looking some advice on whether its worth the extra volume to have a separate internal chamber for a plate amp.

I have a Powersoft Litemod 4HC (with heatsink) on the way as well as an 18 Sound 12LW1400 and am going to build something along the lines of 6th order bandpass enclosure that 18 Sound have on their website: 12” BANDPASS SUBWOOFER. 2 channels to power the sub in BTL and 2 channels to power a set of full range coaxial speakers i have.

A separate internal chamber within the sub for the plate amp seems more secure, but to provide adequate cooling its going to add a significant volume to the enclosure. Or is it likely to be fine in the main chamber. Keen to hear peoples experiences and recommendations.

Anyone ever used RS components to purchase parts from ?

They are the only ones showing stock on the outputs I need

Homemade binaural mic the two elements are headphone drivers.a small step up transformers adds a few db of boost.
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Rion NL-52 Class 1 sound level meter in factory hard case.
UC-59 microphone (-27dB sensitivity).
Rion 512MB SD card.
NX-42EX software package installed (extended function program - logging, RS232 comms, comparator function).
Sold w/Pulsar 105 acoustic calibrator (Class 1).
Never field used - demo unit only - retained as backup instrument. Perfect condition.
Made in Japan.

Located in Melbourne, Australia. Will ship international.

Asking USD$2600 + shipping.