Scan Speak R3004-662000 Illuminator Ring-Radiator tweeters.

https://www.scan-speak.dk/datasheet/pdf/r3004-662000.pdf

Pair, new, unused, in original packing.
Asking for 230€ + shipping.

Regards...

This is the continuation of a discussion over at the Original Thread.

The goal here is to add FIR filter support to Pulseaudio Crossover Rack.

For this I need some help to implement a fast FFT/overlap-based FIR convolution engine into a LADSPA plugin.

Any help is greatly appreciated!

We've been using Alexa AND a Pilot 602, but domestic considerations (and that Alexa sometimes butts in on our conversations) dictates that we purchase a little AM/FM. Recommendations anyone pls

(The Pilot has been moved since the grand-daughters were taking off the knobs, etc.)

For sale is one of my Whammy amps. Carefully built with high quality components, this is fully working and sounds superb. All the right components in the right place.

PCB has 2oz copper HASL.
Rectifier diodes are ultra fast/soft recovery HexFreds
Nichicon UPW supply caps, UKZ audio grade on op-amp decoupling
Vishay Beyschlag 50ppm 1% resistors.

Included is a new unused 10K alps pot, plus 2 x 2.2K Dale input resistors and a pair AD8597 op-amps. Other op-amps are available.

The NJR 7915/7915 regulators are supplied separately as the new owner might want to try improved regs.

Output bias is set to around 88mA with 7.5R resistors

Selling for £120

Parcel weighs 1KG - post UK is £7 - tracked shipping to EU will be £15 / USA £20

Hi

I had the unique opportunity to buy a pair of unfinished Mid Bass Horns from Sadurni . you can google them to see the system he is selling commercially .

my paint job is far from what he offers , just a simple textured black . see photos .

the driver it comes with is the famous and now unobtainable Fane 8M .

i also attached a measurement graph which was supplied by Sadurni . As you can see with some boundary reinforcement it could easily be mated to a subwoofer , or better two , and a 1" driver on top .

these horns are big , but actually for what they do quiet reasonable in size . mouth opening is approx. 31" total length about 30" .

at this point i will only sell or deliver locally , a few hours drive from Madison WI .

asking price is $2500

I bought a couple of these things last summer for the retail value of 30gbp iirc. I believe at one point when Google had stopped officially selling them that some sellers were offering nearly 50pc discount on that.

Luckily I have 3 of them and I find them very useful.

But have you seen what is happening to the prices of them and why? Well I guess people have cottoned onto them being very versatile little things.

Used prices on ebay are getting upwards of 50gbp and have seen some fetch 80gbp +

A strange world we live in!

Hi everyone.
I have a Zenith 5k29 that I am recapping and and making into stand alone amp.
on the stereo inputs they have a 2.7meg resistor bridging them.
I didnt have one of that value and replaced it with a 3 meg resistor.

So, is that a suitable replacement?
And what is the purpose of it anyway?
Third should I just wire the line in's direct to the volume pots?

//

I use ee16 kernel. Frequency: 54 khz.

The voltage drops when trying to draw power.

I put a small piece of paper between the ferrite ee16. Frequency is 114 kHz. Power is great. However, the output transistors get a little warm.

Is that how it works? Or is the core completely closed? Are you changing the primary secondary values ​​to increase the frequency?

Any plans for the store to offer a DAC kit?

Hi I'm looking for schematic/service manual for amplifier board for JBL VT4888DP line array - I'm hoping that it would be easier to acquire as its a discontinued model.
Out of interest do you guys know if it would be possible to get spare parts for this model?

Thanks in advance

I got this amp for £9 plus postage on eBay as spares and repair. Powered on but only hum through the speakers. Had candle wax spillage inside. The photos seemed the wax hadn't burnt causing shorts from the carbon so thought I'd take a chance out of curiosity. I clean vintage gear for a few techs in the area so not a problem to me.

Turned out the input knob had a wack, splitting the preamp board and seems to of damaged the input switch after I repaired the traces I'm still not getting the left channel on most inputs. Reflowing the headphone/speaker A&B board did get the left channel back but only on two inputs, so presume the input switch is faulty or I missed traces. Could swap switch from rec selector or build a new preamp board but impressed with the oversized power supply and its overall sound so may use it as a diy amp 🤔

Anyway it's got a BBC sticker on the back, what's the chances of it being genuinely used at the BBC?

I know someone who works at the BBC in Manchester and was thinking if of asking him about getting old equipment.

Hi I am serching for Primare C22 Remote please let me know if anyone have in unused state

I have built two rather extreme version of MoFo using 20 kg chokes (73 mOhm) and large audio grade Jensen capacitors as output caps. I also built two PSUs for the MoFo's (CLC using 4-pole Jensen Capacitors). I can sell MoFo's with or without PSU's. PSU's are about 25-26 VDC with low ripple. MoFo's are adjusted to about 3A bias which causes the heatsink to reach about 54 C. They played very nice music but I now have M2X mono blocks built into nice chassis and MoFo + PSU's takes up much space and "blocks" a bit for new builds. So I want to see if there was a Dane that could be interested in MoFo's with or without PSUs…...before I disassemble and put into boxes for later use of components.

Price would be taking the most expensive components like chokes, heatsink, Jensen Capacitors, trafos and divide by two. So MoFo's alone would be 5000 DKK for both. 5000 DKK was the price for the two special made chokes. The two PSUs would be 3000 DKK for both but would not sell those alone (only MoFo's alone).

I had originally posted this over at the AVS Forum, but I am going to move my postings to this forum as I think this is more the right place to ask

I am intrigued with horn subwoofers. It appears that they offer some great benefits with regards to SPL and also sound quality. Ability to get the same sound with less power or fewer drivers or smaller drivers compared to other designs like sealed or ported.
However, I am getting confused about all the variations and characteristics of each. Tapped horns, front loaded horns, tuba horns, folded horns etc. Also specific designs from specific people like Danley, Fitzmaurice, lil mike. F20, lilwrecker, Full Marty, Titan 39 etc etc.
Is there a thread or website that explains all of this? For instance, would clearly explain each horn type or category. Like some of the designs have a sealed rear cavity firing into the "horn" pathway where others have the driver "open" on both ends and are placed within the horn pathway using a specific formula. Also is a tuba horn a type of front loaded horn etc? Explanation of the general characteristics of each type as far as efficiency, response etc. Pros and cons. Suitable drivers. Is a folded horn used to achieve a certain box size but same thing could be achieved with a simpler design if you were willing to build a longer/larger enclosure. Finally, an explanation of who's designs are what. For instance, the F20 is a specific tapped horn...but at the end of the day it is a tapped horn.

I have been experimenting with feedback options for an input triode tube in a simple se el84 amplifier. The input tube is 7dj8. The plate resistor is 47K and the cathode 1k. So on a lark I connected a 120k resistor directly from the plate to the cathode and the amp seems to sound better. Just wondering what is going on electrically. Any ideas.

Hi everyone,

I’m looking for a pair of Fostex 103s for my new project.
Does anybody have any?

Thx Bj

Hey guys im having problems with some panel mounted female rca connectors.
I can't seem to get my rca interconnects to fit on them.
What size should these female rcas be?
Is there an acceptable range? Im building a preamp and dont want to use parts
that are not acceptable.
Anyone have any similar experience?

Hi. I'm building a small stereo tube amp PCL82 based (used on old TVs audio) Just 3W per channel and no deep bass nor very high frequencies. The idea is to build a nice retro-look wood cabinet with its own speakers, kind of a "retro futuristic boombox", old school shellac finish. 🙂

I get two (very) cheap 4'' speakers (one per channel) and I need to know the minimum sealed box volume of each cabinet.

Of course, no online data available for the speakers so I tested them with the LIMP software, added mass method (a coin of known weight). These are the output values:

Fs = 133 Hz
Qt = 0.01
Qes = 0.01
Vas = 4.82 liters

With such a small Qt and my not-so-high expectations, which should be the minimum size? Could be smaller than Vas?

Thanks in advance.

Hello

I wonder if anyone has had experience installing and using Pete Milletts software for the HP 8903B Audio Analyser using Windows 10.
Any advice would be appreciated .

what give the most clear sound?

Dual to Mono OPA627BP on buffer IV Dual to Mono LME49990MA

OR

Dual LM4562 on Buffer IV OPA1622

Sound card STX II thanks

ESS has the AMT 1 & 2 on sale again, $155 & $145 respectively.

Dear all,

I'm considering buying my first quality-entry-level turntable for my small vinyl collection (about ~40). I'm planning to grow it very slowly in the future, with select pieces only and to give that analog feeling & LP sound a run when I want it so in an evening after work - otherwise I'm a big fan of lossless digital (both PCM and DSD).

Back to turntables, I see tons of mainstream devices, direct drive ones, automatic ones, with USB option (D/A type), etc. Not sure if they would fit my needs, I can use my hands, so minimal automatism (auto-return at the end) would be nice but if the needle just keeps in the very last circular groove for couple of seconds (or minutes), that's not a pain either.

-----------------------------------------------------------------------------------
So looking at prices and some online stores, I stumbled upon the Rega Planar 1 and Planar 1 Plus.

I'm not a big voodoo-believer but rather a down-to-earth guy.

The Plus is a Planar 1 with a MM -> Line-level built-in amp, with all of its advantages regarding keeping low level signal as short as possible to avoid noise pickup via longer external cables. I like this idea very much, to be honest.

Actually that's what I wanted to do with a regular, amp-less turntable too: mod it to have some kind of OPAMP or JFET based, very high quality amplifier board directly beneath the tonearm and put stereo XLR outs onto the chassis, with a truly balanced setup and signal level for external signal transmission.

Now seeing the Rega 1 Plus, I might only need the Rega 1 (without 'PLUS') and have my little mod made later on.

Would you recommend this turntable in general, or are there better options for the price ? (New only).


I've read good stuff about the Pro-Ject entry models too, but I'm not that deep into the vinyl world. Any opinions ?

And last but not least, the all-evergreen question of MC/MM: I'd like to give MC a chance, do these (amp-less) models run with MC cartridges as well ? I mean the Planar 1 and an equivalent (or better) Pro-Ject in the almost-same price range. And open to any kind of other brand too, of course.

To-be listened vinyl collection is widespread, just like my taste:
- a NOS, never played, ultra-mint-condition Karajan Collection (Deutsche Grammophon, with Berliner Philharmoniker) with about 10-20 vinyls or so
- Talvin Singh: HA, OK albums
- Pink Martini: Sympathique
- Dire Straits: Brothers In Arms
- Some good-old trance and techno LPs (ca. 5 pcs)
- Verdi Requiem (Karajan)
- Mozart Requiem (Karajan)
- Jane Fonda workout double LP (mint condition )

Going to try soon the new Jean-Michelle Jarre Oxygene Trilogy, Electronica and Equinoxe collections, Thievery Corporation, Tycho, Groove Armada, Morcheeba, Hooverphonic, Norah Jones, etc..


Any thoughts about the mentioned turntables ? (or different ones)

I have tried several sites, via google and have got different formala's and results, all from 1 AWG to 9 AWG. So I please need your help🙂


20 x 22 AWG = X AWG when collected in one bundle?

Hello everyone,

I'm exploring some headphone amplifier designs, all OTL. It seems simple enough to attenuate any DC voltage from the output voltage terminal by putting in an appropriately sized coupling capacitor. However, to preserve low frequency gain, the capacitor values I'm looking at imply an eletrolytic.

That electrolytic capacitor could eventually be all that's isolation a listener from dangerous DC voltages. Given that headphones go on one's head, I want to fully understand the safety implications here.

My understanding is that when electrolytic caps fail they tend to fail open circuit-- which OK from a safety point of view.

Can anyone comment on how safe a headphone amp with an electrolytic output capacitor is?

An example is the 30 uF cap in each of the schematics shown in the link below.

Aikido SLPS & Hybrid Headphone Amplifier

From a recent F7 build I have some leftover transistors sets.

Each set includes:
2 pcs 2SK170BL (Idss matched)
2 pcs 2SJ74BL (Idss matched)
2 pcs ALF08N16V (Vgs matched)
2 pcs ALF08P16V (Vgs matched)

The K170/J74 Jfets has been carefully chosen for the F7 circuit and were confirmed to yield the desired distortion pattern of the F7 (THD < 0.1%, with h2 10dB above h3).

My asking price per set is 100 euro + postage. With each set of transistors I will provide a complete sets of passives (PRP 1/4W resistors, Bourns pots etc.) to build two amp channels.

SOLD OUT

PM for questions and details.

Fenrir Speaker Kit drivers (one stereo pair) as described here:

Completed project: "Fenrir"

Includes "new in the box" never used drivers:

- Rival Audio R176-P-08 Carbon/Pulp Woofers (quantity 2) List price - $119 each

(reference Paper woofers by Rival Acoustics – Rhythm Audio Design )

- Wavecor TW022WA06-01 22 mm Tweeters (quantity 2) List price - $60 each

(reference Wavecor TW022WA06 22mm Textile Dome Tweeter with Ferrofluid )

- OPTIONAL - Bamberg Engineering CNC machined Facet MDF Baffles (quantity 2)

- Documentation package

You supply the crossover parts (crossover schematic and suggested parts list provided in documentation) and the enclosure, binding posts, cabinet damping, etc.

WITH BAFFLES: $250 plus shipping costs to USA recipients and Paypal fees

WITHOUT BAFFLES: $225 plus shipping costs to USA recipients and Paypal fees

I recently did a gig with networking amplifiers, it was a bit crazy compared to normal networking of PCs, ( which i normally do, since i am a In Networking ). But i think of taking in few jobs of that sort, since it is different and give a good feeling after it is accomplished
Anyhow, I also going to start off a course in CCNA,( Networking related). with the time constraints, ( doing my own thing after hours )can anyone recommend a good online college to study CCNA course?

I know many might not get it, but for the people who are in networking can help out if you can recommend a place , do reply.

Thank you in advance
Alex

I've found plenty of discussion about speaker cables, but not much about cables for speakers that have each channel driven separately.

I've designed and built a pair of active three-way speakers. I'm using a miniDSP to generate the crossovers and I feed its analogue outputs to the multichannel inputs of a 7.1 receiver via DIY Canare star-quad interconnects. These are unbalanced, although this could conceivably change sometime in the future.

I now intend running six "two-conductor" speaker cables from the AVR's speaker outputs to a wall plate (these cables will be 5' long) and then under the floor through my crawlspace to the speaker positions (a further 15' and 25' of cable). Three cables will supply three channels on one speaker and three on the other.

I would like to hear your collective wisdom with respect to how I should construct and configure these cables. With six two-conductor cables bundled together for 20', should I expect inductive interference?

I could build each cable by sandwiching two 16 gauge "zip cord" cables together, twisted and encased in braid, to make a DIY 13 gauge star-quad cable, but I would have to do this six times. I don't mind doing this if there would be a benefit, but would the six star-quads interfere with each other anyway?

Are there viable alternatives? Would six runs of 14 gauge plain Jane cable be good enough anyway? Since most of the cable will be in a crawl space, I'm not concerned about anything being plenum-rated.

Thanks for your help with this!

I'm looking for crossover schematic of Tekton DI for my summer project.

What I know so far.

- The size of cabinet.
- The model of tweeters .(SB29RDCN-COOO-4)
- The model of midrange (eminence beta-6a )
- The schematic of tweeters/mids
All attached here at post

What I don't know

- 2X Midrange and 2X Subwoofer crossover schematic.
- Eminence subwoofer model number.

I hope you can help me to complete the puzzle.

Hi,

Years ago I owned Omega Speaker Systems speakers with Tang Band full range drivers that I liked. Today I have a pair of regular 2 way speakers in box enclosures with bass ports. I was thinking of converting these to a full range driver speaker if possible. I thought I could use a 6.5” full range driver to replace the woofer, bypassing the crossover and tweeter. Will this work? Thanks.

Hi everyone,

I thought I'd share a circuit that I am currently developing to sell as a PCB. It's a high quality RIAA phonostage with an 'electronically cooled' input stage, and also features a rather interesting and unique topology to filter out the antiphase rumble that resides in the stereo difference.

Gain 40dB @ 1kHz
Vertical rumble cut-off 146Hz
Lateral rumble cut-off 14Hz
Supersonic filter 42.5kHz

Hello, today I was testing out an amplifier kit . I was using my smartphone as audio source ( Sony xperia Z5). The amp was playing no problem, turned it off, hooked it up again later and you could barely hear something in the speaker, tried headphones on my phone, one channel sound perfectly fine the other ( the one that was hooked up on the amp) I could barely hear it.
I wonder what might happend, the amp has input decoupling caps so DC shouldn't got into the phone's jack. (Sadly i learned this the hard way, I've damaged two other phones a few years back because of this on my diy experiments with amplifiers as I was a noob didn't knew caps block dc going back into your audio source.)
But how did it happen again, I measured 0v DC at the jack, 5v before the caps. So no Dc into the phone, AC from the negative feedback could go into the audio source? Is this what happend? I don't want this to happen in the future, I don't know what I did wrong.

The two phones from the past, sounded very distorted but still loud. This time no distortion but very very weak signal.

I Have killed the headphone amp(if it has any)or the DAC ( if it has one or it uses the DAC itself in the snapdragon processor.
Do you guys think if a mobile phone repair center can fix it , or they have to replace the whole damn mainboard/ motherboard?.
I' ve posted here because i couldn't find anything similar on the web,

New to the forum, and re-establishing my hi-fi system.
My Rega Mira v1 integrated amp's face plate has a number of cracks, couple corners broken off, just showing it's age.

I have been trying to find a source for possible replacement parts for it, even up to the Mira v3 amp, but not having any luck at all. Any ideas or resources you all know of?

Also: how hard is it to replace the RCA inputs? A couple have broken insulator innards.

Thank you all so much!

I'm rewiring a solid state amp. What is a good way to do the internal power wiring from the back of the amp to the on/off on the front and back again to the trafo?

My other amp uses just four wires. No extra insulation, not twisted (see picture) .

Hi Guys,

Check this out, looks good in pic but ???? Wouldn't it be great to build a BLH with helper tweeter if specs are suitable .

2 unit DavidLouis P12 hiend 12 inch fullrange full range speaker | eBay

Hi everyone,
I'm new to the forum & have a problem with an overly bright tweeter on one of my Musical Fidelity MC2 loudspeakers (v1's), which presumably means the tweeter has 'blown' or the crossover is faulty?

Can anyone advise me about possible repair or replacement of the offending parts & help me restore some level of speaker performance?

Many thanks, 🙂

Not sure how many have found Hammond iron to be grossly out of spec and very poor quality, but.... time to gripe about this junk.

I've been working on a small 45 amp... opted to use a 271X power transformer which is rated at 280-0-280 @ 60ma. With a 40ma load, the secondary is putting out a whopping 320-0-320! It also puts out a huge magnetic field and induces a huge hum output into the output tube. Just taking a flat piece of steel and holding between the power transformer and the output tube drops the hum level significantly.

My brother built a pair of 50-watt monoblocks and used Hammond iron.... the power transformers were so bad you could put a small screwdriver against the core and it held in place while buzzing away. He eventually had to dump them and replace with Dynaclone P782 units... and the amps went from humming to quiet. Hammond is also useless in helping to resolve issues with obviously defective components.

Seriously, Hammond quality varies so broadly I'm starting to think they have monkeys winding the stuff.... not much else can explain just how bad this stuff is. Oddly, I used an Allied transformer (yes, made by Hammond) on the previous amp... same identical layout, chassis size, parts, schematic, etc. and it was dead quiet.

I'm about to swear off anything Hammond... as it's a cr@p-shoot at best and a waste of time to design and build with it. I now have a useless amp due to the high hum level and am debating on building the second amp.

Regards, KM

I have been following the "field coil" discussion since the aborted Fertin group buy in Brian's earlier thread.

Some time has passed, can anyone give a rewiew/impression/2nd hand impression on how the Supravox 215 Sign.Bicone (not field coil) stacks up to the 215-2000 EXC (field coil)? And I guess to other well known speakers as well.

I am wondering if the extra money is justified. Also, what about a Supravox group buy?

Regards

Mike

Hello everyone! My name is Kyle, I've been into home and car audio for quite sometime and have recently been wanting to take my hobby a bit more serious. My current setup is pretty basic and purchased second hand. A pioneer elite VSX-55 with HSU book shelf speakers and a HSU mk3 12 sub. I look forward to upgrading and adding new pieces in the future. Look forward to getting to know you all!! Have a great day!

Hi all,

I have pretty much zero knowledge in this area but would love to work this issue out with your expert help.

I have a 2009 Mitsubishi Pajero (Australia) with a stock stereo system, MMCS head unit, Rockford Fostgate sound system and a roof mounted DVD player. I believe the same system is used overseas and in America in the Mitsubishi Outlander.

I have an RCA jack in the cargo area of my vehicle that I want to use to play music from my phone and also run a video game console.

Whenever I use a 3.5mm to stereo RCA I get extremely bad static. If I use a games console with the RCA I get a blurry almost colourless image and NO sound at all.

I have used multiple cords, devices and a ground loop isolator. When I use the ground loop isolator on the 3.5mm I get NO sound.

I believe I've narrowed it down to only the cable that runs to the roof mounted DVD player unit from the rear RCA jack. As when I play DVD from this unit the sound and image that is transferred to the front head unit are fine.

The front head unit plays CD's and radio without issue.

I'd love some ideas of what to look at and try in order to solve this issue!

Thanks in advance for your help!

I keep reading that the 4 drivers are TC4452's but the on this one there are 2 TC4422a's and 2 MIC4420ZT's. Can i replace all of them with TC4452's? It appears that the TC4422a's are for the low side and the MIC4420ZT's are for the high side. Does that sound correct?

My latest project:

577-B597-B-876-F-4-CE7-AEC2-119125-C3-FA69 — ImgBB
935-F8875-F84-F-429-E-888-C-691130-B7-B97-C — ImgBB
1-FCB78-F7-C1-AD-49-CB-9-BC3-A5-CF2-AEE563-D — ImgBB
EF74-FFD8-F17-F-427-E-8612-5887-D584-B5-F7 — ImgBB
BF945262-FAF0-402-F-9-EF6-63-EFCC9-DDCA0 — ImgBB

I hesitated posting since it is just a redesign of an old system. It has a beautiful rich stereo sound, honey drip and silky. The integrated dual turntable is excellent and fine tuned to work with the phono stage and power delivery, of which there is plenty of.

What I did:

- Cleaned up all contacts and switches.

- Got rid of the bottom cabinet. Constructed danish-like tubular legs and assembly.

- Got rid of the gaudy doors, took apart one door and reused the material for a simple sliding door. I sewed the doors’ fabric to cover the new door’s centre panel. The hardware is self-closing drawer slides.

- Added the auto light when you slide the door open.

The final outcome is a very Japanese looking object with modernist influence. First stereo that I regret leaving the house.

Hi All,

Anyone have a circuit for the DAC section of the Arcam Alpha CD 6 player. ?

Mine has no output from either channel.

Are there any common faults?

Andy

Referring to the round holes on this Philips PCB, both sides shown.

Looking for class-d chips with digital inputs (i2s), hardware control (no external µC) and some power (>100W) i found the automotive amplifiers from ST Microelektronicś:
Class D Audio Power Amplifiers - Digital Input Audio Amps - STMicroelectronics

The info brief looks promising
- SNR and dynamic range are excellent
- the feedback loop includes the output filters
- i2s input
- plenty of output power
- can be operated without external µC
- but give a lot of goodies with i2c control, ie. live impedance monitoring
- ...

Did anyone used one of these chips? I could not find any reference schematics or application notes - asked ST's support - but got no answer until now.

We lost another great musician.
He was SO much more than writer & keyboard player with Pat Metheny.
I just wish he had released more music as leader.

RIP Lyle
Lyle Mays, Evocative Pianist Who Helped Define The Pat Metheny Group, Is Dead at 66 | WBGO

mlloyd1

A friend passed on the sad news of the passing of Richard Dunn of NVA.

Thoughts with his family and friends

He brought a different perspective and approach to his commercial brand and I'm sure had many followers.

Hi there,

I am building my house right now and was going to use a sonos sound bar in my great room. I was going to build this into the wall and have it flush, however once I opened the box I noticed that the sonos sound bar actually projects sound out the sides/back. This will clearly not work as it would more than likely distort the sound.

I am looking for a white sound bar that only projects forward, that would be comparable to the sonos playbar. Any suggestions? I was going to put the soundbar in a void in the wall, and then do millwork around it to have a nice clean look.

Someone had suggested to me that bose has a nice white soundbar, but when I looked at it, it seems to project sound out the side (and possibly back) as well which would again cause issues if it is in the wall.

Thank you

Been away for awhile working on my spouse-acceptable 4-horn speaker and it’s done, more or less - I’ll have to post a show-and-tell sometime soon. (I’m certainly no expert, but it’s been an interesting project, and maybe someone can learn from my mistakes.)

Anyway, _with equalization_, using cheapo measurement tools (Dayton audio imm-6 mic) I can get a decent looking response curve composite of the 4 drivers, using pink noise and the FFT part of the AudioTools app on an iPad:

...but in listening tests, the vocals sound pretty well defined but “distant“ and a little thin (like the singer was literally some ways behind the rest of the band.)

Since I’m after good _sound_, not a pretty eq graph, I’ll probably try playing with the equalization and see what sounds best, but I’m curious. Without spending hundreds on good test gear I’ll use once, am I doing it right? ie _Pink_ noise, with an FFT graph? Or should I try to equalize to white noise, or with the RTA module?

If you are looking for an extreme quality amplifier and you don't need high power this is the project for you because nothing can have higher performances.
After 20 year I have rebuild the same project because this is perfect on all aspects except the efficiency but this is normal for a true single ended class A.
This project is an hybrid amplifier composed by a tube voltage amplifier followed by a single ended mosfet current amplifier with an exclusive configuration.
I have published several articles about this my current amplifier and this design was the winner of the award in the Circuit ideas in May 2000 on Electronics World which is the most important electronic magazine in the world.
This amplifier was built by a lot of people around the world and everyone are enthusiastic about the result, the sound is compared to that of the best single ended vacuum tube amplifiers but this have a higher performances in terms of driving capacity (damping factor) and low distortion.


Here the measurements and the files to produce the pcb.

Folks:

Does anyone know of a good source for low-cost aluminum or brass Imperial standoffs? I'm specifically looking for #4-40 0.375" male-female standoffs, but wouldn't mind picking up a few other sizes. Metric standoffs are plentiful and cheap -- I can find brass M3 10mm m-f units for under $0.15 apiece, but their similarly-sized Imperial cousins are harder to find and about 3x more expensive.

Regards,
Scott

Hello


I'm thrilled to have finally joined diyAudio community after so much time spent reading post on the forums.


I'm an amateur guitar player and I started building tube guitar amps from kits and from scratch for about a year now. "Princetone" is a homage to my first amp build, a tweed Princeton (which I play everyday). I plan to get on audiophile amp territory aswell.



See you around 😎

Hello,

I am thinking about building an Computer-based DSP/Active-Crossover for my home cinema. My plan is to use an Dante-PCI-Card as Input and one or two USB-based oder Thunderbolt-based Audiointerface(s) with enough analog outputs like an Motu 24AO. So the hardware is not a problem but the Software instead.

Is there DSP-Software for computer available where I can do the following:

- Mixing, copying and Routing input channels to Outputchannels (for example one dante input should be copied to three outputs for three way active xover)
- Highpass, Lowpass and Bandpass filters for xover (Butterworth, Linkwitz up to 48db ocatve)
- 96khz / 24bit operation (maybe upsampling before)
- Low-Shelf and High-Shelf
- Linkwitz Tranform
- Parametric Equalizers

Is there I software (independent if Windows or Linux) available which can do that with standard Audio-Devices in the OS (Asio/Wasapi in Windows or alsa/pulse in Linux) with a graphical interface?

I know that brutefir and some linux command line tools can do it but something graphical (best woud be webbased via browser) would be better so you can do changes on the fly without writing a new config file for each simple change in the config.

So in principal a DSP software like you have it in DSP-Controllers like "Nadja under control" for my Nadja Modul or "Hypex-Filter-Design" (for the hypex modules) just for Computer (which will work with system audio devices as input and output).
Is there something available which can do this?

I have for sale two pairs of Audax AP130Z0.
Price is 50 Euros for each pair.
All units are in very good condition.
Only their terminals, due to soldering, are not in a perfect condition but without any operating problem (see photo).

I'm a new member of this community and would like to share my gained knowledge and experience.

Im trying to choose between two different Western Electric amps and Im hoping you can point me in the right direction.

I am debating between the WE124 or the WE118a. I would change the 118a to use 2 6L6s vs 4, but other then that it would be the same.

So ideally the only difference between the two amps would be the phase splitter. The 124 uses the input tubes as the phase splitter and the 118 uses an input transformer for the job.

Would love to hear your guy's thoughts on the matter.

I’ve seen many classic corner speakers, often horn based, but some including JBL/Altec are just standard vented enclosures. I quite like the idea.

But when reading up on the subject there seems to be a split on whether the bass frequencies are usefully boosted or the room is over excited and the bass suffers.

Is there a definitive answer as the shape holds a fair amount of WAF points for dealing with large speakers?!

Hi folks,

I have 2 complete Kits of Powersoft 3004PFC (4-channel plate amp with heatsink, connection board and DSP-D) for sale!

These are new, one had been mounted for testing, the other needs still to be unpacked...

We did not need this much power, and the units were simply too big in our monitors.

Price: Euro 1.000,00 + shipping (this is really ridiculous..)
Located in EU, so shipping to US will be around 100 Euro.

I have other two 3004PFC amp modules available, might be completed to IS version.

What size punch amp is this ? I tried googling gut shots and can't find it.
thanks

tested on a Hickok TV7-U were 38 is low
tests
90
89
nice tubes 115$ plus shipping from 60491
thanks rick

Audiobank AAB-1.1600

Hi, Could anyone perhaps help me out with the Power Suply Schematic of this amp ,Or maybe even complete schematic. Please and thank you in Advance. (Audiobank AAB-1.1600)

I posted this question on another forum, but read some good content here so decided to join.

Still not confident in my ability to interpret old tube datasets, so I thought I'd just ask here. I have a pair of 6K6gt that need an output transformer. I am considering two designs: 1) push-pull with triode connections, 2) parallel single-ended with triode connections. Both designs keep me around 5 watts.

Regarding OT primary impedance, what values should I be looking for to accomplish each design separately?

I think that I understand the Naim hierarchy for Naim Pre's and PSUs, but reading the specs for the PSUs doesn't tell you what supply rails are actually utilised by the 282 and the 252 in each pre/PSU combination.

Can anyone point to work or investigations carried out which identify the supply rail requirements of the Nac 282 and the 252?

I'd just like to understand what is actually going on.

Many thanks

Well, I'm far enough along in my test cabinets, that I thought I'd create a thread for this.

I reformed by dual 55-2421 cabinet to end firing, moved the first horn path to center, instead of offset, and made it out of fresh ply, so it's 'to length.' VERY respectable numbers down to 43hz. No it's not flat to 40. but it's within a half step, so I'm happy.

The numbers aren't bad.. I especially like the very flat 103db through the 50's and 60's, a little dip in the 80's, and then off to the races as you hit low hundred's.

For $50 in drivers and 1.5 sheets of ply.. it's pretty respectable.

Measured C-weighted, corrected to flat, rounded down to nearest .5 db 2.83v / 1M / Drivers in series

HZ DB
40 99.5
43 102
46 102
50 103
53 103
57 103
62 103
66 103.5
71 102
76 101
82 101
88 101
95 102
102 104.5
109 107
117 108.5
126 107
135 105
145 102.5

Hi all. I have built a pair of 2 way sealed box speakers which comprise of a 10" woofer and a 1" dome tweeter. Xover is a linkwitz riley and xover point is at 4000Hz. The box is somewhat undersized and I have used some polyfill to improve
The woofer's performance. Qtc is at about 1.2. Despite the high Qtc the bass is not that boomy and works OK. Box resonance is about 71Hz and f3 is about 63Hz. When I turn up the volume the mids from the woofer tend to swamp out the bass.
My question is can I use some sort of equalization
To dip the mids to melow out the sound. I have read that a BSC may be used and if so can it be applied after the xover. Othereise please advise what else I can do to improve this scenario.
Kind regards
Billy D...

This amp is using 2SK1190 as the power supply fets .

Does anyone know of a good replacement for them ?

I was having problems with my amp that had the old style driver boards without offset adjustment pot. So I purchased brand new stock blank driver boards (last version made) and stuffed with new parts. I can bias the amp OK, but the DC offset is 26-27 volts in both channels! Also, don't understand why my relay clicks on with all this offset. The DC offset adjustment pot does nothing when turned. Any idea where I should start looking?

I am looking for Heresy parts:

*K-22 woofers
*Type E crossovers
*K-77M tweeter- need one

..also looking for a Forte 2 passive. Thanks

For Sale:

Restored Magnepan MG3.5r. Perfect condition - Cherry rails and Black Socks.

Bass and Mid Voicecoils reglued with Magnepan supplied 3M N30 Glue, ready to rock another 30 years. Tweeters are also perfect and have the Tweeter protectors. The Crossovers have been rebuilt with good quality components.

Pickup in West sub of Chicago...

Need to sell to finance the next restoration project - a set of Quad ESL-63.

Hey all, got a Carvin DCM2000L 2 channel amp. Does not fire up. Fuse OK. Lost interest......I have a schematic too. Nice clean 1U chassis...

$60 + ship? Pickup in west sub of Chicago.

Marantz 3600 Per-Amplifier (Stereo Control Console) . Per-Amplifier is in need of repair. Powers up, right channel works perfectly, left channel is distorted. All buttons, knobs and sliders work and function as intended but left channel has distortion. Exterior is very very nice as seen in the pictures. Silk screening still looks nearly perfect on the face plate. Super clean on the inside. I'm not an expert on vintage Marantz amps but it appears to be a very original unit. It was working when placed in storage 5 years ago. It could be something simple or more serious but I've priced it accordingly. I'm glad to answer any questions and test any item that can be tested with a multimeter.

Pre-Amp is on eBay at 295.00 + shipping with no reserve. See eBay auction link for more pictures - eBay Auction

I also have the matching Marantz 250M Amplifier, also in need of repair in another listing, see link below eBay Auction

Thanks, Rick

Hi guys i got this amp in for repairs. The problem was it was going into protect mode i managed to sort that problem the issue i have now is there is no drive signal to output fets on the pre amp im not sure if someone removed this u7 ic because the amp came from a previous repair

Hello everyone, I have a kicker zx400.1 with problems, the amp turns on and produces output signal at low gain when I start turning the gain up the amp goes in to protection mode, if I turn the gain down the amp comes out of protection. The amp come in with R108 (270 ohm) and R106 and R107 (220 ohm) burned, I have replaced the resistors and TL074C on input board.

I've been using op-amps to boost signal from my sound card to test low-sensitivity tube drivers, and have been very impressed with how the particular op-amps I have been using have performed, very low distortion and what distortion was there was 2nd and a tiny bit of 3rd.

I've found that the most objectionable shortcoming of my tube amp is noise, not distortion. I've paired it with some pretty high efficiency speakers and have had difficulty getting things very quiet. The first problem I fixed was ground noise by installing input transformers. I also had a lot of weird noises coupled into the ground when I connected to a PC. I fixed that by installing an opto-isolator device in the USB connection between the audio adapter and the PC. Phew.

Now I'm down to just hiss, but more of it than I'd like.

I designed the following input board to 1) reduce the overall gain of the amp (I have more than necessary) and 2) just try to do better at low-noise design in the first stage.

The board is fed by the output of the Jensen input transformer (hence the RC) and goes to an LM4562 stage that is similar to the input stage of an instrumentation amp setup. I chose the LM4562 because it has low distortion, good noise performance, and can drive heavier loads so I can choose resistances that will keep noise down. I also chose it because it does particularly well at keeping distortion down with large common-mode input swings; most op-amps do not do that well. It is well-suited to non-inverted duty. With +-17V supplies, it will put out 10Vrms with very low distortion, which is all I need right now.

I put the option of a second stage ADA4700 for later use (I have a new driver idea with less gain, so I might need more up front). The ADA4700 can get me from 10Vrms to 30Vrms. It has more distortion than the LM4562 but is the lowest distortion amp I can find that can handle voltages this high. I also put a trimmer as an AC balance adjustment. The amp this is going into has no global feedback loop so nulling out the 2nd harmonic generated in later stages has a big effect on lowering overall distortion. Of course, if the trimmer is not desired in another application, I can install a jumper wire and bypass it.

Anyway, what do you guys think of this heresy? Anybody see anything major or minor that I'm missing in this approach? I'm sort of new to this op-amp design stuff, having only read Douglas Self's small signal audio design book, and he doesn't exactly cover the best ways to drive tube circuits with op-amps.

I'm looking to buy some TIP36 type transistors and there are several different part numbers, TIP36C, TIP36CW and TIP36CG. The G appears to mean lead free, but I'll be damned if I can find what the W means.

The spec sheets for the C and CW are exactly the same except for the part number and some notes on changes to the document, but the CW costs about 20% more than the C. Does anyone have an idea what the difference is between them?

Not long ago I was looking for advise on Tweeter and Woofer selection for Two way crossing. I was looking for ribbon speaker which could have decent vertical dispersion. After a great help from forum members and gathering info from other sources, I had to settle for RAAL 140-15D which is considered to have best off-axis coverage for any ribbon tweeter(correct me if I am wrong). As I am going with that high caliber tweeter I guess I must pair it with suitable woofer. My limitation for woofer is that the size should be 3" or 4" max and nothing big and should be recommended for sealed enclosure so I picked up ScanSpeak 12MU-4731T0. I will using two woofers in series and cross them with tweeter in parallel. If there is a better woofer that can be paired in combo of RAAL 140-15D then please, I am open for suggestions.



This being my first crossover I need to be corrected and advised to do it right. This is what I have done so far using software "Passive Crossover Designer". I am posting few pics below.







I would like to know what am I doing wrong and what to improve and do correct.

Hi guys

This is my first post, so, I apologize if i did anything wrong.

I work in a audio Enterprise and recently we decided to create Kits of Woofer + amplifier. We bought 1000 units of an amplifier from China TPA3110 based. However, after all of units arrive, the seller told me that 10% of all have some issues (clipping, probably).

I created a simple jig to test all of them, as you can see in the attached picture, but I'm not sure what is the best process to do it. I was thinking to use a fixed frequency in max volume and see what will clip. (I've already tested some units and some of them really clip instantly.


What do you think guys?

hello,

This is from a little venture where i had to fire my business partner and this is some of the stock that is left over from that split.
The planar is a Radian Audio LT2 in the waveguide, 33 left at AUD $55ea
The woofer is also Radian but its only new so its not listed on their site yet $30ea. 33 left of those
I have a few demo boxs built also,
3 x singles with drivers $180ea
3 x dual with drivers $250ea

I dont get notifications that someone has contacted me so if i dont respond quickly, that is why.
Thank you

View attachment 4WF25-data sheet 051718.pdf
View attachment LT2-data sheet 060517.pdf

Hello
I would like to develop a class D with a switching frequency around 400 or 500kHz, a bus voltage of 200V (or dual 100V), with a pulsed max current of about 10A (no continuous high current needed)

Initially I was inspired by TIDA-01605 which uses UCC21530 gate driver, and I selected the SiC mosfet C3M0065090D.
Advantage of this design is that there are transformers which allow for a virtually rail-to-rail configuration, and the design is already done so it is more easy to avoid mistakes.

However, lately I came across LMG3411R070 which are integrated modules with a GaN mosfet inside.
In theory those modules should be more efficient, I am not sure which of the two design is best. For sure the second has the advantage of using much less space.

Now, the idea could be to apply the concept of the TIDA-01605 design to these modules, but I am not sure how easy it is and I am not fully confident on the comparison that I did which for the moment is in favor of the second design.


What is your opinion?