Hello,

I've just inherited these ~70s speakers; they sound dreadful. However I really like the solid wood cabinets.
I'm completely new to diy speakers but I'm comfortable with electronics so I'll want to mess around with these some more later but for now I'd just like to get them playing decently.

A lot of you guys recommend building a proven design first but I haven't been able to find one that's particularly similar.
The closest I've found in size is this one: http://www.troelsgravesen.dk/STUDIO-101-mkII.htm but the design is very different or this one https://sites.google.com/site/undefinition/bookshelf-speakers/virage but the sizes are also quite different.
So right now, I'm thinking of looking for a 7/8" and a 1" dome tweeter similar to the builds above.

Has anyone else retro-fitted a cabinet?
What are the big things that I need to consider?

Inside dimensions: 55cm x 26cm x 21cm (to the bottom of the mounting board) HxWxD ~ 30 litres
Height available to mount speakers is around 41cm, inside is completely empty.

Can A power supply be Built for krell KBX crossover

hi, i have mostly fiddled around one chip classd solutions and bought broken nx3000 to repair and learn a bit. so sorry if this is a bit newb question.

classic protect fault, one output fet shorted(gate short) bought some SUP90100E fets to replace original IRFB4227 as there is half RdsON and bit higher current rating, lower Qg, and i thought that was bit too easy.

fast forward to when parts arrived and replaced, amp turned on worked for 10 seconds or so, and blown another fet again, but this time it was not shorted gate but drain source short.

i put one of old 3 fets in place to get some scope shots from gate outputs after i checked all zeners and diodes in drive circuit, i turn amp on just few seconds wait only for scope to get data and turn it off so i can see what is going on.

attached is picture of all 4 gates, low side is correct at +-10ish Volts, but high side has gate swinging +-80V or full rail voltages, i cant wrap my head around how is this possible and already done all i can so i post here for someone smarter to point me in right direction.

amp is half bridge, and gate driver ic is IRS20957S with some i think its called totem pole pnp npn transistors. croped schematics also attached.
thank you and have a nice day.

These popped up in eBay. I have no affiliation with the seller and know nothing about this particular pair or the seller.

I have two pair myself and don't have a use for these.

https://www.ebay.com/itm/166700453729?mkevt=1&mkpid=0&emsid=e11021.m43.l3160&mkcid=7&ch=osgood&euid=895eb2d22b70463f9e283208e22075b0&bu=43191483615&ut=RU&osub=-1~1&crd=20240408051940&segname=11021

Hey all,
I've been running through some scenario's in my mind and i was hoping to get some input from the crowd on here,
I've been diving into the operating principles of the Bose 901,

How you all think the reflected sound would be affected if using larger full ranger drivers, say 2 x 12inch full rangers vs the 8 x 4inchers on the back face?

Or ditch the full range entirely and use a combination of mid-woofers and two horn loaded CD's on the back face?

Just curious if people have thoughts on this.

Tweeter: Visaton DT94 (8 ohm)
https://www.visaton.de/sites/default/files/dd_product/DT 94.pdf
Woofer: Dayton Audio RS150P-4A (4 ohm)
https://www.daytonaudio.com/images/...rs150p-4a-reference-series-specifications.pdf


I replaced the drivers in my parents in-wall rears (blown tweeters and 4oz magnet woofers). Reason being they're going to be used as rears in a mid- fi larger home theater setup (Denon 3700 5.2.4)

I decided for the widest dispersion to use a cone with ~4.25" diameter and a 0.8" tweeter, crossed low.

The woofer is 2nd order at ~1700hz, the tweeter rolls itself off 2nd order at 1700hz. I put a cap on the tweeter for thermal protection (~1300hz)

I'm not concerned about hf distortion or cooking the tweeter - I listened for distortion and measured temperature after pink noise, and everything is fine at levels well above listening.

No, I didn't sim things, but it sounds very good. I chose things to keep everything as simple as possible (tweeter has a q of 0.54 and a flat impedance curve which is up just 10% at resonance/woofer is flat for 1.5 octaves above xover and has perfect horizontal dispersion past 80 degrees at xover)

I want to attenuate the tweeter just a little bit. My concern is: if I put 1 ohm in series with it, will q change and screw up the phase?
If yes, no big deal, the Denon 3700 has XT32 speaker/room correction and these are only rears.
I believe the increased efficiency between 9 and 16khz which ranges +1.5-4db, averaging about 2.75, is what causes the tweeter to sound bright - making want to attenuate it some. Both drivers are listed as 90db /2.83v. So maybe I should just leave it as is and EQ the tweeter?

Most importantly, will I induce ringing in the tweeter by adding series resistance while using its natural rolloff (q~0.5) as the crossover point? If so, is there a maximum amount I can add before things become audible? I assume ringing will manifest itself as a lack of clarity, which I don't want, especially around 1700hz - the ear is sensitive there and speech intelligibility would be affected (not that people talk through the rears that often, but still)

hi i was trying to restore an accuphase e302 with burnt parts, Some has gone thru these amp and install some non complementary parts for the pre drivers stages and it did made the amp oscillate and blow the output transistors and burt some other parts it would be helpful if i had a schematics for reference and i would greatly appreciate it. Thank you. My email is jmdimayuga@gmail.com

Hey
I have a pair of ice power 250 plate amps that I’m trying to find a schematic for. I reached out to minidsp but no response. How can I somehow extract the schematic from the assembly? Both these amps are not working and I’d like to take a closer look and perhaps repair them.

Using it in a not very spacious room, so rather quiet/medium volume listener. Really loved that warm class A sound that PM80 MKII brought.
Phono stage is also important(using MM MP-110 cartridge) so that might leave NAD amps to the background, maybe.

All suggestions are welcome.

Hello,

Clearing out the garage, and realized there are too many speaker projects I'm simply not going to get to. Everything is for pickup only - I'm not shipping anything! Have a 9 month old 2 year old at home, so barely have time to 💩, let alone package things and ship them. Probably have even more once I dig around some in the garage.

cheap:

$20 - 6" flared Precision Port

$30 - very high end 18" cast frame passive radiator from Exodus Audio (Kevin Haskins shop), w/ weight kit

$95 - older LC Audio Predator based amplifier with huge power supply. Nice case is engraved with 125 RMS @ 8 ohms, 250 @ 4 ohms, and 500 @ 2 ohms. Serious power supply! Heavy!
L C Audio Technology / Predator SE (not exact but approx. same amplifier)


Cheers,
Tal


gone:

24" diameter x 24" height Sonotube, with three 24" 3/4" wood endcaps (intended double thickness for driver side)

single cheap and old black vinyl Infinity 8" two way bookshelf speakers with the woofer missing (had a pair but think I accidentally disposed of one, sorry)

12" car audio box, but well made, though extremely ugly. Braced, sealed, and maybe 1.5 cf from memory, made by a friend for his car and donated to me for Audio Purposes.

$20 Panasonic SAXR-10 receiver with switching amplifier (actually digital/powerDAC, not class D). Unfortunately, doesn't have the remote, so can't select digital inputs, so goes through A/D conversion for the power amplifier. :-( If you get a remote for it you have a very nice amplifier!

$25 (what I paid for it): HSU 10" ported subwoofer, their original "True" subwoofer, w/ dead amplifier. Well made 10" box, with two large flared ports, and one port bung for variable tuning.

12" car audio box, sealed not ported, the ubiquitous carpeted kind. Actually, have two of them.

triple 12" home subwoofer box, used a Peerless XLS 12" driver with two XLS passive radiators (covering the front three faces of the rectangular box), with a huge cutout for Keiga's 1000 watt plate amp. obviously, no drivers or amplifiers included.

$30 Audiocontrol Model 200, has a hum when on. Otherwise nicely made amplifier with lots of features. https://www.audiocontrol.com/downloads/home/discontinued/architect-model-100-200/Architect Model 100_200 Owners Manual.pdf

$25 - enclosure only for highest-end JBL studio subwoofer 6312SP, ported, carbon-fiber baffle, uses fancy push-pull voice coil with neo motor
$45 - driver from above, neo motor, dustcap sadly torn/pushed in; heads-up: it's a 2 ohm driver! LSR6312SP | JBL Professional Loudspeakers

$45 harmon/kardon AVR520 receiver I was using with a MiniDSP for active crossover projects as it has inputs directly into all 5 channels of the power amplifier (look on left for jumpers here 404 Not Found). Amplifier is rated at 75/100 watts into 8/4 ohms. https://img.usaudiomart.com/uploads/large/1243564-95c99170-new-old-stock-harman-kardon-avr-520.jpg

$75 - SVS 20-39PCi large vertical ported cylinder subwoofer. Either amplifier or driver damaged, but I think it's the driver. Pretty intense subwoofer!

$45 - Tannoy Di8 DCT coaxial 8" speaker, white, deconstructed. Was going to build this into a nice box for a center channel, but didn't get around to it. Have all of it, just the driver is not in the box, and the box is taken apart. Includes a spare tweeter! Click on Details from this link. Click on 'Details' in this link: Tannoy Di8 DCt Series Surface Mount Single Speaker - Black

$67 - NHT VS-2 speakers that I don't need. Very good MTMs in a piano black enclosure that go down cleanly and loudly to 75 Hz; designed by Ken Kantor for home theater.

I am selling a TP Buffalo 32S as well as several modules:
LCBPS
LCDPS
Placid HD
Placid HDBP
Opus BP
Also, Raleigh Audio USB-SPDIF

I would like to get $275- Shipped CONUS

Thanks,

-Steve

Posted this in another forum but figured I’d try here considering how helpful this community has been over the years.

Hi folks. I have a Zhili 834p clone with a separate PSU, the black and gold one. It’s been sounding pretty great. I upgraded the coupling caps a few months ago to VCAP ODAMs and it sounded even better. Just yesterday it sounded weird, sort of veiled and muffled. I confirmed by swapping in another phono pre as well as a couple of integrated amps. Did a bunch of tube and cable swapping, as well; I tried everything to the extent of my limited knowledge. All scenarios had same results with the 834p clone lacking highs regardless of whatever I swapped and all sounding great when the 834 was removed. I don’t know where else to look, would appreciate any insight or guidance you may have. My friend who gave me these caps and noted they may take some time to burn in and sound odd along the way, but this is a bit more pronounced or obvious than what I’d imagine cap burn in would be (myth or not..). I’m stumped!

My GCD-600 cd player works ok while turned on. But the problem comes when powered off…. After a few minutes of being off, it starts to click (relay click) and the display turns on dimly. The clicking is erratic In tempo. If you turnt it on, the unit goes back to normal and works as expected.

im attaching the service manual, hoping that someone can share some light into this issue. Most probably is a cap that has high resistance, heats up and shorts the circuit to ground, maybe.

Any insight will be highly appreciated.

cheers,
Luis

Hi everyone,

I recently acquired a Kuba Arosa stereo/record console with a Telefunken Turntable in rough condition. From a few quick searches, I’ve found that it was produced from 1958-59, but little else. I know very little about vintage radios and turntables and even less about vintage wirings, parts, etc, but there are some obvious flaws which i will attach pictures of. Does anyone have any insights as to the potential issues with these systems?

I still need to purchase an updated plug, so as of now I have absolutely no idea how the systems function. If anyone has any suggestions about parts to buy in the meantime, it would be greatly appreciated. Thank you!!

​

Hi, I could use some help making sure I buy the right part from Mouser or Digikey. Thanks

Looking for the evaluation board for the Hypex UCD180OEM it makes it easier to connect the modules to the power supply. Im in the USA

I have been thinking about the flare rate of multi entry horns at the tap point

Is there a way of calculating the flare frequency for each point down a horn flare?

I saw somewhere that it could be done with this formula:

343/(4*PI*L12)*Math.log(S2/S1)

I am currently making a webpage to help with designing MEH, you can put in S1, S2, L12 then it will graph the highest frequency, cancellation notch and hopefully lowest frequency loaded by the horn at each tap point.

This is where I am at so far:



Doesn't look great but you can upload the slices output by ath or generate a conical horn

Hello All!

I hope someone here can help me source a replacement part for my Myryad MA-360. Specifically, I am looking for the RCA socket circled in the photo. It is a dual RCA socket that needs replacing....

I have applied large capacitor tuning technique, by series a large capacitor to the woofer, to my closed speakers. In theory, it states that this action will result in changing the slope of the bass response from 12dB/octave to 18dB/octave. So, does it mean my speakers now will produce bass response close to the Third-Order Quasi-Butterworth of the vented box? And how about the transient response? Will it behave like closed or vented box?

I have searched the internet and have found no one that has done this. I have looked at the schematics of the Ampex 200A and the Studer J37, they are just simple class A tube amplifiers. I know the amplifier is only a part of the machine but it is the actual input/output. So if you where to built the circuit with the same tubes and the same values wouldn't that at least be reminiscent of the machine it was designed off of? An Akai M8 reel to reel for example. Most people strip these beautiful machines just to make a guitar amp from. Seems to me it would be very easy to replicate the circuitry form one without destroying antique gear (They say the decks are not that great, on paper yes, in reality they sound uniquely fantastic IMO). The schematics tell you everything you need to know.

Hi folks,

I am restoring a vintage Criterion MkVII receiver which I saved from the land fields. With this post, I have two goals:

1. Get help with setting the correct bias in the power amp section

2. Get help with understanding the power amp circuit.

Little bit about the Criterion…It was the last receiver developed and sold by Lafayette. As a matter of fact, the company was closing doors when it came on the market. There is no information available other than the attached schematic that came weirdly, with the owner's manual. No budget for service manual or service afterwards. Personally, I think that it is a very clean sounding receiver and one of the prettiest of the era. It is very simple and elegant looking one.

With regards the first question above, I need to setup the DC bias, but I have no idea to what value and where to measure it. Normally, for class AB amp it is measured across either or both R21 and R23. Am I correct and if so, how do I calculate the proper bias voltage?

With regard understanding the circuit…here is what I think I know about it and a few questions at the end:

We are going to look at the left channel only.

Signal travels though C1 and is applied at the base of the left transistor of Q1 (Q1 is a supermatched pair of transistors in one enclosure) of the longtail pair comprised of Q1 and Q3 which forms the IPS. Overall negative feedback/closed loop gain is provided at the base of the right transistor of Q1 through the R11/C7.

The signal is taken from the collector of the left transistor of Q1 and applied to the base of Q5 which forms the VAS. after that one half of the wave (lets assume sinusoidal signal for simplicity) is applied to the base of Q11 and the other half through C11 is applied at the base of Q9. Afterwards it is easy, one half goes through Q11, Q15 and Q19, while the other goes through Q9, Q13 and Q17. Q7 is a voltage source and along with the STV4H's diodes and R17 form the bias spreader of the amplifier.



Here are the questions:

1. Is my general understanding of the circuit correct?

2. How come that the feedback is applied to both: the base of the right T of Q1 and Q5? I would expect that it is applied only to right T of Q1.

3. What is the function of C9 and C31?

4. Can someone explain the dynamics between IPS, VAS and the feedback gain loop?

Thanks in advance.

Best

Soundork



P.S. Here is a little interesting fact as a reward for reading this far: The only thing wrong with it is a bulging capacitor in the PS. The rail voltage is 50V and they have a cap rated at 50V max. Wicked weird…😊

Thread split from http://www.diyaudio.com/forums/tubes-valves/156564-need-good-phono-stage-design.html
___________________________________________________________________


Phono preamps, Phono preamps.

Everyone wants a "good" phono preamp. And it must be tubes. Why..., must it be tubes, is my question.

I have been in electronics since 1952. And not once, have I a seen a great tube preamp; that did not require re-tubing.

Re-tubing a tube preamp, removes the balance and the smooth tones that was once its signature. You will spend large sums of money trying to get that sound again, that will never return. It will be close, but no cigar. Never! Again.

Why, because tubes are not made equal. The grid is the secret to its sound. And they are never made the same. Believe me..., I know. I worked at GE and Tung-Sol tube factories. And it does not matter what you do or how hard you look.

So I will tell you a great secret, one that very few know.

There is only one great phono preamp. And I designed and built it for the US Government in 1961. And it uses only three transistors. A transistor that was designed in 1956. That is still made today, for as low as 3 cent each per 100.

When I was young, I went to Bell labs, and met the people that were designing transistor chips for many other companies. They were starting to make silicon units. They gave me what they called the greatest transistor ever. They told me that thousands of different transistors will come after it, and people will over look its outstanding values, because they will misunderstand it. Or they will misunderstand its data values or they would not know how to read a transistor data sheet.

My the phone preamp used three 2N2222A. It is very, very quite.

You may being thinking, I am crazy. Yet allow me to lay some facts on you.

a. the max. noise level of a 2N2222A, is 4db. No more
b. its dc current gain is 50 to infinite, at 10na/10volts
c. its dc current gain is 75 to 325, at 1.ma/10volts. Which is much better than some of the more new transistor designs for high gain. Believe me, any thing above 375 in gain, is only better noise level. Not a better transistor. And its real Vceo is 50 volts, not 40 volts.

Once it is built, you will never want for another preamp. Because you will never lose that smooth warm tones of a 2N2222A. Will not believe your ears.

email me, if you are serious into audio, and I will send you the pcb. It is in CircuitMaker 2000 format.

Take Care

Ivey

Hi guys,

I recently bought an Audio Research SP-9 MKIII, but I can't adjust the volume very well in my system ... the Eiclone amps (diytube project) seem to have a high input sensitivity.
As explained in the Audio Research's instruction manual, I tried to reduce the gain of the preamplifier by 6db, however it's still high.
Does anyone know the input sensitivity & input impedance of Eiclone?

Any comment would be very appreciated.
Thanks
Andrea

Hi guys,

I would buy an ARC SP9 preamp and I found two, one an MK1 and the other an MK3, in good conditions. Price difference is 300 euro.
I know there have been some changes between versions (https://www.arcdb.ws/model/SP9). But really important for sonic performance?
What are your experiences and suggestions?

Thanks
Regards
Andrea

Can the 6BQ6 be used instead of a 6V6 through an adapter which EBAY has for sale?

The intention of this thread is to get practical feedback for my application: HOLMImpulse

HOLMImpulse is Non-Commercial freeware with full functionality (No limitations or trial periods) running on Windows XP/Vista

Download HOLMImpulse Here


Other diyaudio thread for theoretical discussions
I started a thread, which went rather theoretical:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=144984
If you have theoretical questions/features/bugs/doubts then please refer to that thread.

The main goals of the application

• Measure Impulse-response
• Measure Frequency-response (Gain and Phase)
• Easy and fast to use (Simply select your soundcard and click measure)
• Work with any soundcard
• Use the latest measurements techniques without complicating the interface

I would like your response

• I know that there is no manual yet, I'm working on it...
• Please post your measurements in this thread, it would make me very happy to some measurements and it would help me improve the tool.

Why I'm doing this?
When I started building my DIY-speakers I could not find any freeware satisfying my needs.
I believe that whatever you can measure you must measure instead of fabulating...

• Does the grill make any reflections?
• Is the relative phase correct?
• Is the relative gain correct?
• Is the tweeter broken?
• How does my carpet or sofa table affect my impulse response?
• ...

Above questions can be answered by HOLMImpulse even without a calibrated microphone, since you are often only interested relative measurements (Like above)
I have attached a measurement of my girlfriend 's speakers (Rega EL8), where the manufacture had the mid/woofer out of phase in the one speaker causing the dip at 4 kHz
(It's of course resolved now...)

Hello!

I think I need to recap my Hypex FA plate amps after more than 5 years of service because they started to emite slight his/noise after powering them up. They came with very cheap/low tier caps from the factory.

The choice would be Nichicon UVZ or Panasonic ECA. The Panasonic is roughly twice the price of the Nichicon.

Would the extra cost of the Panasonic be worth or the Nichicon is also good enough?

Can I expect sound character differences between the two?

Thanks!

For sale , 4pcs used JBL 2408J. 15,000 pesos. good condition

If in the same box with a woofer and two equal passive drives (in vertical in the same column with 20 grams of added weight each) I move 10 grams from the upper drive (the one closer to the woofer) to the bottom driver, the Fb is still the same or change?

(To be clear, before: +20g & +20g; after: +10g & +30g)

I have some Sanken 2SC3858 and 2SA1494s in T200 package pulled out of a Urei 6260 amplifier because one side has two of them blown. The rest of them all measure much lower hfe gain than the data sheets suggested. The NPN 3858s measure in the low 20s when the data sheet says it should be a minimum of 50.

So I was wondering if damage or age can effect HFE?

I own ADS L1590 speakers. They had bi-amplifier modules as an option for using them as the active speakers. The module internally consists of active crossovers and amplifiers for low- and high-pass sections. I'm going to enable their active biamplification mode. But I plan to use the better power amplifiers with the DSP instead of finding the very rare complete modules. So, the objective of this project is to reverse engineering the characteristic of the active crossovers. However, I'm not a professional electronics engineer or electrician, I have basic knowledge of electronics. I have tried simulations of the active crossovers. Here are the results.

Low-pass section:




High-pass section:




Combined response:




Could anyone verify my results? And how to obtain the corner frequencies and Q factors, I believer they are second-order, which are required to be used in setting the DSP?

I have a NAD C352 (2004) amplifier which has recently started making very loud crackling noise from L ch . It first started with soft crackling noise , lasting only for the first few min, after power ON and later the noise faded away with music playing properly on both ch. Now no music thru L ch. , only loud crackling noise, while the R ch is playing properly. Maybe the music is drowned behind the noise

During the initial troubleshooting , I found that the crackling noise is coming only from the L ch. (of both pre-amp out 1 & 2) regardless of volume control position, Offset- bouncy reading on L ch due to noise and under 2mV for R ch.
But if I remove the pre-power link from the rear side and directly connect thru power amp in, the output is proper without any crackling noise, no issues with offset.
Currently, for testing purpose , I'm using a pair of small 3" speakers, with series 47R (to reduce power)

All these years, no recapping was done, as recommended on many online forums and YT, largely due to cheap caps being used by NAD (perhaps, maybe they survived all these years due to active cooling fans). Slight browning underneath the PCB observed due to excessive heat dissipation (inadequate heat sink and undersized power resistors provided by NAD).

I have very basic troubleshooting skills and basic tools (cheap DMM & soldering kit) to carry out any further tests. If required , I have a friend , who has a DSO , ESR tester, variac, Fluke DMM, various capacitors and resistors for testing purpose in his LED lights mfg. company. The only problem is that I will have to carry the amp over there and work on it during office hours only.

I would be grateful to you all , with helping me solve this issue.

Repairs/Mods carried out in distant past by me (unrelated to the current problem)-
1. Installed 4 cooling fans, powered by ext wall wart, after the warranty period was over
2. Removed bad 20K balance control and replaced it with 10K+10K x 2 resistors (0.25W) (2009)
3. Reflowed transistors in preamp section due to audio cutting out intermittently (2009)
4. Removed tone defeat switch as its contacts went bad and shorted it with a link , such that the tone defeat was always OFF with tone controls working (2011)
5. Replaced the TL082 pair with OPA2134 and soldered missing 0.1 uF film bypass .
The other unconnected section of opamp was properly terminated thru 15K SMD input to gnd and output to gnd , output to input feedback (as the original TL082's unused section was left floating).(2012)
6. Basic dust cleaning/servicing carried out every year.

Hi All,

I am currently restoring a Wharfdale PM700 Powered Mixer and I am looking for the circuit diagrams for it. The only one I have been able to find is unreadable.

Hoping someone out there has it 🙂

These posts extracted from the main miniOnken thread http://www.diyaudio.com/forums/planet-10-hifi/188257-minionken-fonken-picture-gallery.html, please post your pics & comments there, this one is locked. dave


I'll start with the latest.

Bernie (doesn't post here) came by today with his Mar-Ken12 to get my help detailing them and wiring in the drivers. This is the 1st set i've heard (Chris has had our (unfinished) build at his house, but with stock drivers (they are now veneered awaiting time in the spray booth). Bernie's build is of solid Douglas Fir with some dark exotic or semi-exotic vent spacers (the fir used to be his floor). The aged "orangish" colour of the fir goes really well with the copper drivers.

Even with few hours on them, i get the impression that these do some things (imaging) much better than the Classic GR Mar-Ken12 that i've listened to extensively.



This is the 1st of the trapezoidal miniOnken (irregular octagons if you count the champhers) -- the configuration will spread thriout the line. The tapered shape was the solution to fitting the wide bezel A12 into the small volume it wanted (same as A10.2, FE127e, and EL70 (A10.2 will also go nto a larger version))

dave

I tested everything that might be wrong but everything is prefect. All other channels work great, even the sub channel.

Does anyone know what i might of missed checking or any other help will be appreciated!
I uploaded some pictures in case you need them.

Hi Guy's

Please Register your details for the 2nd group buy - Pre Order

Wolverine development Thread
Wolverine Build Thread

Youtube build series

Hi everyone. Its been years since I was here. I gave up playing guitar/bass for a while and now I'm back. since I've been away the likes of Squire and Epiphone have been turning out some high quality (meaning consistent, error free well finished) guitars in the far east. However some of the components are 2nd tear so a culture of retro fitting electrics has grown up. Not just pickups but pots ( I don't get why) and caps - orange drop or even paper in oil.

Can any one hear the difference? Is there a scientific reason why 50 or 70 year old technology cap would sound different ( assuming the same values)?

lHello everyone,

I am looking for a 3 way DIY speaker kit. I have seen that Troels Gravesen offers some 3WC Classic kits. Has anyone had any experience with these kits and can give me some tips on how these models differ in sound?

The loudspeaker is intended for a 23 square meter room. Of course I am also grateful for other 3WC tips.

Many thanks, Jo

Was reading a bit about SPICE http://www.normankoren.com/Audio/Tubemodspice_article.html and was surprised by this throwaway line.

…poor phase margin can make an amplifier particularly sensitive to cables and loudspeakers.

Click to expand...

How can speaker cables affect an amp’s performance, poor phase margin or not? I have always been a cable skeptic but this author hardly seems like the kind of guy that spouts audio woo. Is there really something to speaker cable quality other than gauge? If you have a higher feedback amp what should you look for in speaker cables to avoid problems?

Sold

Built from the Mensicus Audio kit, one of Jeff Bagby's designs. Cabinets were made by Javad Shadzi and are absolutely beautiful. Sad to see them go, but I need to pare down my collection.

$300 OBO. Local pickup preferred (San Francisco, CA), but will consider shipping if you cover the cost. Sold

Hi everyone . I kindly ask you for advice.
I need a semiconductor amplifier to be used mainly for measurements with REW and microphone. I don't rule out using it for a secondary audio system, therefore possibly with a good quality/price ratio.
I prefer a vintage amplifier from the 70s-80s-90s to look for on the used market. it must be relatively easier to repair than other models in the event of a fault. expenditure not exceeding €100.
Hello and thanks .

8+4+1 larger standmount is my favorite concept. Not overly complicated to build, 8inch usually offers good bass extension.
I had 12MU and 21W already around waiting for the right project, and I got lucky friend of mine offered to lend me 9800 tweeter. From the very little info available on tweeter I understood this tweeter should sound exceptionally. With +-0.1mm Xlin it is needed to be careful with crossover frequency, and my preliminary target is 3000-4000 LR2. From previous projects with 12MU I know this midrange is fine with that Fc as well.

9800 and 12MU are off-centre to minimize diffraction effects. This also means I need to take the horizontal measurements from the both sides. Speaker orientation for the listening will be drivers in so this side of the horizontals will be optimized.

9800 got new faceplate to get closer to 12MU, CtC is 100mm and Fc~3500Hz. These are good ingredients for nice power response.

I chose tilted front baffle to enable LR2 crossovers for all drivers.

Hopefully I will have a time to measure the drivers for the crossover in coming weeks.

I am stumped. This amp is challenging me. I have recapped and all new outputs and drivers. Power supply was recapped also. I adjusted offset and idle no problems. I then load tested both channels separately. 8 and 4 0hms. Everything was perfect distortion was lower then specs and output was higher. I ran it for a good hour. I then decided to try to bridge it and thats when all the smoke came. I never even got to load it. I simply switched the switch to bridge and turned it on and smoke from a resistor and a power supply transistor popped. Main fuse blew. Any help would be appreciated.

Anyone got one of these for sale by any chance?
It's to operate a Primare DVD26

Need some help/guidance on where to start with diagnosis on this CD changer. I've owned it since new (1990) and it was rarely used. This unit has maybe 40 hours of play time on it, most of the last 25-30 years it's been in storage (indoor, climate controlled). Recently pulled it out to play a few CDs and it's not working. It spins up the disc, changes speed, the laser will move from inside out, but never is able to read it and it gives up. Here is a short video of what it's doing: Login to view embedded media
I've searched around online and even found a few threads on this forum. I checked the main board and the original electrolytics look okay (I did not remove or test any of them). The lens is clean (IPA). The motor seems to be a bit noisy and vibrational--not sure if this is within tolerance--not sure how this would have failed just from sitting. I tried probing the marked RF point on the laser board with my scope, basically nothing there.

Another note, when I first opened it up, I saw it actually spin the CD backwards, and it was also dropping the disc while still spinning. Not sure if that means anything, but made me think the motor or a sensor may be faulty. Since trying it a few more times it's stopped doing all of that.

What is the general process for diagnosis on a CD player? It appears I'll need to get the factory service info to do anything, but should I chase the motor vibration first? Or address the lack of RF? Or are these machines old enough now that they should get recapped before doing any other diag?

Thanks for any advice,
Michael

Hi,

I'm trying to build a set of bookshelves using the CHN-50P , using a design similar to the one published below



The idea is to split this and use them as 2 standalone bookshelves supplemented by a Subwoofer.

Would it be a better idea to place the 2nd driver on the top like an up-firing driver. I believe the Microtower castle does this



Or to the outisde. Below is a mockup of the right side speaker facing me. The Slot Vent port is front facing in both designs




This will be a living room speaker(s) and the idea for using the 2nd driver was to increase off axis response and also increase the loudness. It will be placed very close to a wall on a shelf about 18 inches off the floor

Is this even a feasible idea?

I've also made a mockup using the similar design from MarkAudio's website as a sound bar



Thank you

Hi all,
My trusty Cyrus III integrated amp have blown a fuse. So reading on the fuse that it was a T1AL 250V 20mm glass fuse I replaced it but the replacements keep blowing.

Has anyone had the same problem and fixed it?

Thanks

A couple of years ago at Burning Amp Nelson gave me a pair of ACA 1.1 boards and some semiconductors. What is the difference between the 1.1 and current versions?

Greetings Friends. A friend is the happy owner of a Vox AC15TB, 1996-2004 vintage. As I'm learning, there are many versions of the AC15 out there, with many opportunities for confusion. This may be the correct schematic, but it doesn't say AC15TB anywhere on it.

As I understand it, this version was built with one channel, and retains the Top Boost characteristics of earlier 2-channel versions of the AC15. The owner of the amp would like to rework this circuit to lower the treble frequencies, to achieve a tone closer to the Normal channel of a classic AC15.

My inexperienced-tech mind is leaning towards a simple removal or replacement of a Cathode bypass resistor (perhaps C12) to allow more of the lower freqs through. But a bit of research online points to a Cathode follower in the preamp circuit that could be adjusted in other ways.

Do you have any experience with this issue? Any advice, opinions, warnings welcome. Thanks for taking a look!

w

hello, I would be very happy if someone could explain why it is 2.36V on the based off the transistors.

i have measure voltage on all the mos-fet and transistors and printed it out in the pictures.

Hello,

While I realize this question is from a green level standpoint, I'd be very interested in what you have to say or think about this.

As a guitarist having done a few successful tube amp builds, the current availability of very nice stereo effects pedals (primarily those with time-based reverb/chorus/delay) has got me seriously thinking about arranging for a single cabinet combo that contains two full and adjustable 20 watt 6V6 push pull amps, providing as much compactness as can reasonably be had. (To mention, this amp would likely have two independent power transformers that I concurred may be best located at opposite ends of the chassis rear with input section at the front middle.)

While experimenting with layouts and doing my best to follow prudent and time-tested layout rules, I kept arriving at a place where the two output transformers were in somewhat closer proximity than I might have optimally preferred. Now, while I have in the past set PT to OT proximity on a chassis using the "heaphone trick" and dancing the OT around for minimal hum/buzz/noise with PT powered, I am not able to establish any intuition at all on what the modes of OT-to-OT interferences might be, at least to the point where they would be creating a practical compromise to each other's performance. It was very eye opening to actually hear in real time how a PT will induce audible noise in an OT but, I admittedly have no way yet to determine that in two output transformers and how proximity will affect each other. What I can say is that this is just a guitar amp that is by its own nature likely very forgiving of interference elements that would not be tolerated in a decent hi-fi stereo amp. A touch of minor crosstalk would not call for the end of civilization as we know it for my application although, this would be a clean pedal platform that is out there in the local venues helping Dad pay the bills.

Can anyone relay their experiences in what the concerns and effects are regarding output transformers in proximity to each other and possibly any guidlines in establishing safe proximity?

Thank you for your time and efforts in my behalf.!!

Best,
Phil D

Located in Perrysburg Ohio
These are in very nice condition.
$1900 OBO

Can you tell me if the IRF across the board are all the same to replace? Some have 29k on them while the others have 30k.

Hello everyone,
I'm planning to design a DAC with the ES9033 chip. For this purpose, I read the ES9033 datasheet several times. I want to design a tiny and efficient board, for example I'm considering a low noise ldo like LP5907-33 for supply. The DAC will operate entirely in hardware mode and DSD will not be used.
I have solved all the other issues in my mind, but I am confused about the I2S input. Namely;
According to the ES9033 datasheet, the chip's I2S inputs for PCM are DATA1-DATA2-DATA_CLK and MCLK. It is clear that DATA_CLK = BCK and MCLK = MCLK. However, as far as I understand, DATA1 is the Left Channel Data, for example, while DATA2 is the Right Channel..
In this case, do I need to separate the DATA line as right and left with a simple logic and LRCK clock at the I2S input and enter these lines?
Or is there a system in the chip to use these two DATA lines with LRCK?

Big hello with Christmas 2023. Scan Speak project. 🙂

2.5 way tapered transmission line with Scan Speak units. Always wanted to build something with legendary 18W Revelators and this year two pairs landed in my workshop. One pair is from 2022 and bought 6 months ago. One pair produced in 2023 I bought now as a Christmas present from me to myself. All four look the same and I hope they will sing the same. Illuminators D3004/6600 will come in January and be installed in augerpro's waveguide to complement the package.



Why TL? Because I would like to hear that deep dry bass 😎 and I don't want to build another too small 6+1 inch speaker whistling around 50 Hz through its too small port. I want to build something bigger and different. That's why double dose of 18Ws as a bare minimum with Sd surface of 10 inch driver. Later to overstuff it and test how too big aperiodic / sealed box with low Q would sound and would I like it or not - for my future projects.

Idea is for a longer time in my head, I went through Onley, Bailey, Augspurger and MJK and all available here on diyA. I have come to the level where I can produce TL in Hornresp in a few seconds 🙂 and it was good course about behaviour, changes and important parameters in Tls. MJK made nice writings recently as an extension of his work from two decades ago. He is trying to demistify and make fair comparisons to various bass enclosures. It was a good guide for complete TL design from scratch.


So, few goals:


1. 2.5 way tapered TL towers with 2x SS 18W/8531G00 plus D3004/6600 in waveguide;
2. Internal volume around ~ 60 liters plus minus 3 dB;
3. Tuning not below 30 Hz and especially not above 35 Hz;
4. Bass quality above quantity and lowest minus 3dB point;
5. 5:1 taper as an optimum between length, width of the box, physical buildable size, Start and End cross sections and slow blow mouth velocity;
6. Low diffraction cabinet with thick rounded front baffle (I have CNC router) for directivity control of midbass for better match with waveguide;
7. Additional external curved sides to make elegant teardrop-ish cabinet, glued with CLD layer;
8. Simple minimal audiophile passive crossover 😍;
9.. High end sound of course;
10. Sexy look blink blink;

In next few posts drivers measurements with DATS, calculations of geometry according to MJK methodology and Hornresp simulations...

Goal for this Christmas vacation time is to cut and build-with-screws test boxes as a hardest part. If they pass initial measurements then will be glued and further developed into something serious...

Tested when first purchased but unused and boxed since then. £50 the pair excluding shipping.

Do the XA30.8 and XA60.8 use the same as in identical supply voltage ?

Oneminde

Looking at some parts I have bought in the past, I see a price increase of at least 150%.
Under these conditions our presence in the diy will be problematic in the near future.
How we can deal with this?
Is group buying a solution to this problem?

I bought these to have a play with them having read some good things about the small driver. Didn't do much with them apart from quickly adding a 15uf cap to roll them off as I used them for a short time sat on top of a LF module. They really didn't like any bass!
£25 plus post

I have a Sony reel-to-reel Tape Deck (1960s vintage) whose pre-amp has failed (the capacitors have fallen apart). Mechanically, the deck works OK. I no longer need to use the deck for recording but I'd like to play all my old tape recordings and convert the ones I want to keep into digital. To do this, I think all I need to do is take the 4 wires (2 each for the L and R stereo channels) from the playback head and feed them into my modern Marantz amplifier/receiver. However, I expect I'll need to feed them through a suitable preamp. If so, where can I get one?

I'm new here and a new owner of a pair of sd1s (conventional tweeter). They're infinite baffle speakers with a nice functional look roughly the size of Celestion sl6s from I guess the late 80s.
They sound very good to me, timing through the mids and highs seems good, but I wondered if anyone had experience positioning these? I currently have them on Linn Kan stands—an open frame design about 53cms high, and about a foot out from shallow bays surrounding a chimney breast (a foot out from the breast that is). They're about 3 feet from either sidewall. If I push them back I seem to get a little more presence but slightly forward gives a little more information to string tone; but otherwise these seem curiously unresponsive to positioning in my high ceilinged largish, squarish and bare room (whilst basically still sounding good). Anybody else have a recommendation?
And thanks in advance.

Over the years I’ve found myself trying to filter the Multiway thread into horn speakers and non horn speakers. I don’t know the history of these forums but multiway vs full range has never seemed like the best way to categorize projects of interest for me. I tend to think more in terms of horns, towers and OB. Anybody else feel there’s a better option than what we have now?

There are some really cool avatars in use, and some really so-uncool-they‘re-cool-again avatars…

I confess: I „identify“ some of the fine folks who use a foto of somebody with these and this can be a bit disturbing. OTOH, some are just perfect, and they are biasing whatever is written under their name to the positive. (Looking at you, @Mark Johnson , @SRMcGee , @meldano , @ggetzoff )

A bit naive, isn’t it? 🙃🥳

Hello guys.
Forgive me if i have posted this in the wrong forum. Unfortunately my dvd player/home theater 5.1 system has died.
The 6 speakers are in perfect condition though. So rather than buying a new one i thought of getting an amp for it.
Mainly because it would be a lot cheaper ( i suppose), and there is no reason to let the 6 speaker collect dust.
I tried to find something for the specification, but i had no luck.
My computers motherboard has 6 rca output, so i am looking for a suitable (preferably cheap) amp/crossover that could utilize my speakers.
The 4 corner speakers+center are 15W 6 ohm , and the Sub is 30W 4 ohm.
Any help is appreciated, thank you all in advance!

A friend will shipping his fault device of this model, but I told him that I would first try to get a service manual with schematic diagram.
Maybe one of the member can upload this.
Thank you very much.
P.S.: On the portal from Elektrotanya I only find the CDM7 from the same Dutch company.

Looking for a AN8290S spindle motor drive IC for a Technics CD player.

Hey people,

I found these "LM1875T" ( I assume the common, not so bad sounding, fakes as everywhere). I just forgot I have them, as I changed to LM3886 just because of the higher output power. I remember them as really good sounding chips, and it would be a pity to not put them to use.
I thought, maybe I could try two of them for my tweeters, which are powered by LM3886's atm. It's all fully active, so the different output power can be aligned easily.

best regards

I'm gauging interest, here.

I built an integrated amplifier with B1 as preamp, but I didn't like the amplifier section. So I tore it apart and sold the amplifier section. Now I'm debating what I should do with my assembled B1 with Korg Triode.

If I hold on to, it might sit for a while. It's only been for a couple of months and it's already covered in dust; sorry for the pics. So selling it might make sense. Let me know if you are interested.

This board is the OG. It's the Christmas board. It's been fitted with high end parts (Vishay Dale resistors and Nichicon audio capacitors) and spec'd out to handle up to 35V.

I want to build a sub for the LFE channel for movies. I have good main speakers but I'm lacking rumble. After much digging around, I was able to find drivers with decent Q and low Fs in the local market (Argentina). The rest of the available drivers in the market are "car audio" drivers for SPL competitions with Fs all >40Hz.

The available drivers are Alpine 12" with the following specs


I've simulated them in WinISD and got these curves:




Running environment:

• The speakers will run in a 3x6 meter room where one of the corners is a bathroom, so the room is more L-shaped (I can provide a floorplan).
• I ordered a UMIK-1 so I'll run REW here to characterize the room as soon as I get it
• There will be DSP and EQ applied after characterization with REW.

The conclusions I arrived to were the following:

• Vented box will be required for low freq (of course)
• Series S will be the cheapest but requires a large box
• Series R will perform the same as an S in a much smaller box
• Series X will go much lower, in a box the same size as S

Now, the questions:

• What's the required SPL for "feeling" LFE channel? If I'm watching a movie and I want to feel the explosion on my chest, how many decibels is that?
• Do I want such a big-and-deep driver as the Series X which will go low , but will require a considerable box? Or will I get enough with a Series R that requires a fair bit smaller box and delivers very respectable -3dB of 21Hz in a 67L box?
• I suppose the answers to the second question is actuall the first: if the required SPL is enough for a R-series with more power I'm willing to sacrifice efficiency for space. I guess it's fine to run the driver at 100W instead of the larger and more expensive one at 50W to compensate, if the required SPL dB is reached?

BONUS: closed box option

All 3 drivers in closed boxes will give a -3dB of 45Hz with pretty much the same curve. 20Hz will be at -16dB in all cases. I read about using room gain to take advantage of subwoofer rolloff. I'm all for using a small box but, is room gain predictable or reliable? Is it a curve or is it spikey depending on what's in the room and its layout, etc? I don't think it'll be very helpful if the room only gives me gains on a single frequency but the rest is the same.

I imagine it's always possible to tame down the excess bass with DSP, than trying to recreate it with DSP gain?

Hello all! I just completed a pair of speakers with a set of Dayton RS-270-8s Tang Band W4-1337s, and a Vifa ring radiator mounted on a horn. I'm crossing them over using a Dayton DSP-408.

They sound pretty fantastic tonally-wise. Problem is, I'm powering them with 3 mono TPA3116d2 no-name boards from eBay and a 24v 16 amp power supply. They are extremely hissy (it's not the Dayton, I've removed it from the chain). Even after lowering the gain as much as possible, hiss is still there, probably exacerbated by the tweeter horn. Hiss can be clearly heard from the listening position. Also, power on pops are so strong they'll eventually damage the woofers.

I'm looking to replace the amps, but I've seen that most class-D amps prefer 4 Ohm loads and my woofers are 8 Ohm.

I've tried narrowing down boards, but all I can find are no-name units from eBay. I can't know if they will have hiss or pops.

I've been looking everywhere and I see that power output will be greatly diminished because of my 8 Ohm woofers.

My search has narrowed down to perhaps the TPA3250 or the TPA3251 chips. I've found some boards on eBay, but I don't know how good they are. I also know I'll need to change the power supply to a 32-36V one.

Any recommendations for a good board will be welcome. I'd love to stay with the 3116 chips, but I can't find any quality boards out there... all I've seen is this one but I don't know how good it may be.
https://www.amazon.com/TPA3116D2-Ta...12-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&psc=1

Here I will detail some of the construction details and set up of the Pete Millett Korg Nu tube Balanced preamp that I have built. Schematic is reproduced for convenience.

Jfets- I chose to use the Toshiba 2SK170BL for Q1 thru Q4. However, I did not have 16 matched ones, so I used the lower Idss values for the followers Q1A thru Q4A and the higher ones for the CCS Q1B thru Q4B with small degenerating resistors typically around 5r to get 0VDC offset. My Jfets were mostly in the 7-9ma range. I asked Pete “Could you please explain to me why you have chosen 1k source degeneration resistors (R6/R8, etc) in the Jfet followers as opposed to self biasing them without any?” His reply “Adding a resistor helps to stabilize the stage current without requiring selecting FETs for a particular current (they can vary a lot, maybe 2:1, without it). If the FETs are matched, the resistor on the upper FET also will give an output voltage equal to the input voltage, as the voltage drop on the two resistors will match.”

Capacitors C6, C7 and C13, C14- I wanted to use film caps from the get go but they are large so I asked whether smaller value caps could be used. Pete responded “The coupling caps are big largely to avoid bias shifts with the signal. Since the tube is in A2 and draws some grid current, using a lower cap will increase distortion because at low frequency the cap will discharge more on positive peaks than negative. So I wouldn't recommend going any lower.” I chose Clarity Cap CSA 12uf for the caps before the Nutube and CDE 940C caps for the ones after the tube. I mounted them under the PCB, as shown in the attached pic.

Microphony- The Nutube was mounted on top of a piece of foam mounting tape attached to the PCB. Additionally, each PCB and cap assembly was mounted using 40mm standoffs onto a base plate which in turn was attached to the chassis bottom plate with foam tape. The PSU’s and the transformers and stepped attenuator were also attached similarly. I cannot hear any pinging when turning the volume knob but you can clearly see it on display as spikes around 5khz when doing the THD plots if you tap on the case. I used the Salas DCSTB Psu’s at 15v output. Nice!

Set up – It took me a very long time, mostly due to inexperience, to get the plate voltage settings where they sounded best to me. I used my Focusrite 2i2 in balanced mode and ARTA software for the FFT plotting and set up. I finally decided on a setting where I could null both H2 and H3. From these null points, R12 was turned ACW to increase plate voltage to get H3 just a bit off its null and R13 was turned CW to decrease the plate voltage of its respective tube section to get H2 up where I want it. This gave the sound I was looking for with the resultant THD plots shown. The plots were done at 0.42V output after 2 hours warm-up using 332k plate resistors.. Here are the plate voltage readings:

L channel TP3 4.07V TP5 6.85V
R channel TP3 4.14V TP5 6.76V

Measured gain was 12.89db Left channel and 12.73db Right channel.

The above settings also result in “negative phase H2” as defined by Nelson Pass. The XLR output connector is normally connected to the PCB outputs i.e. PCB output+ and output_ are connected to XLR pins 2 and 3 respectively. To verify negative phase H2, I temporarily reversed output XLR 2 and 3 and easily noticed the sound had shifted forward. I much prefer negative phase H2.

Sound- I use this preamp to feed my Sony Vfet power amps and Troel Gravesen OBL 15 speakers. Compared to my BA3 and DCG3 balanced preamps the difference I find most striking is that each musical note sounds fuller yet is extremely clear. The other two preamps also sound clear but seem thin in comparison. If you increase H2 further the sound becomes more euphonic but gets muddier. It sounds better to my ears with a very low H3 and a much higher H2 than with a somewhat higher H3 and lower H2. Mention must be made that the overall setting is tuned to perform best with the Sony VFET amps. All three of my preamps throw a very large soundstage but the Nutube preamp sounds the most realistic, especially with classical. Late night listening at lower volumes is also very satisfying. To my great surprise even large scale orchestral works sound excellent.

Thanks to Pete Millett for a well designed, easy to assemble PCB. I like it that all the lettering on the PCB is outside the part outlines so that they are not obscured once the parts are stuffed. Thanks to Nelson Pass for his very informative articles on H2 and to Salas for the excellent DCSTB Psu’s and his ever willingness to answer any and all questions.

Hi!

I was wondering if there is a schematic out there for an audio peak indicator circuit that uses 1 multicolor (red/green) led that turns green under 0dbu, orange betwern 0dbu and +10dbu, and red above +10dbu. The trick here is to be able to turn off the green led gradually after 0dbu and completely off after +10dbu.

Any ideas? 🙂
Thanks!

Hi all diyers,

I have Alpair drivers in the pencil enclosure. I have no complaints. I would like more life out of it. I listen to a lot electric blues and old rock.

I found the https://www.speakerdesignworks.com/halcyon design, it seems very interesting as it adds two small woofers. So the enclosure is nice and small (9 inch face). Since I can control the WAF factor, would it be «better» to use one 12 inch driver of simiar value as the two SB Acoustics 6 inches ?

Does it impose more difficult blend for the sound of the two drivers ? Is it more difficult to make the crossover, it will be my first one.

Thanks for your advice,

Walter

I made a wall-mounted Speaker with CHP90.
I used 9mm MDF to reduce the weight as much as possible, but it is strong enough and I don't feel any vibration of the box.



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Hello Everyone,



I have stumbled upon an issue while doing an application. In this application there is an existing multimode fiber which is installed. We will be using Sony PXW-Z90 and QuestTel's optical extenders. My application exceeds a one kilometer distance which is not supported by multimode fiber. Since changing multimode to singlemode fiber is not an option, I would like to know if there is an option that exists that doesn't require me to change the existing infrastructure to boost the optical signal.


I am truly looking forward to a good response,
John

Hello diyAudio forum,
I was looking at the SE/SE Wire headphone amp recently but I found out that the LME49610/49600 buffer isn't in stock anymore so I looked at alternatives and found the BUF634A.
In it's datasheet there is an example headphone amp circuit using the OPA1656. I drew up a full schematic in Kicad of the circuit Login to view embedded media What are your thoughts on it? Should I change anyhting about the schematic before I go ahead and design a PCB for it so I can test it out? Also, would running it off of two buck boost converter modules to create a dual rail PSU be a good idea to power this? Kind of like how this person does it for his eurorack PSU.

I am looking for advice with crossover design. I am attempting to rebuild a set of Cerwin-Vega! L7 Bookshelf speakers. I have decided to use the following drivers:

Visaton SC5-8 Shielded 1/2" Polycarbonate Tweeter 8 Ohm.

Tang Band W5-2143 5" Paper Cone Full Range Driver 8 Ohm.

The enclosure volume is 0.44 cubic feet or 12.4 liters. I am reusing the existing port (1.69” x5" cut down to 3"). I am stuck with the 0.44 cubic feet as I don’t want to cut open the boxes.

I have been experimenting with Xsim for designing the crossover but have a couple concerns, mainly around the impedance curves. I am not sure what is going with the impedance curve for the Tang Band W5 driver, it has a massive spike at around 54 ohms. Nothing seems to smooth it out and I am wondering it this has any potential ramifications to harm my amp or the speaker itself.

Andy help would be greatly appreciated. I have attached a couple images from Xsim.

Hello all.

I am planning on using an unbalanced 1/4” TRS output to send stereo line level to a balanced stereo amp with XLR inputs.

The cable will be Canare L-4E6S. In the middle of the cable I’d like to use a small box to do the actual splitting (i.e. 1 in, 2 out). Should this box be non-conductive, or metallic? If the latter, to which ground/shield should I bond it?

Hello, I have sunfire tga-7401 amplifier. The amp has three fuces. Two for current sources and one for ac line fuse. Unfortunately one of the fuce holder is broken and I couldn't find the replacement. Without the fuse holder, fuse does not stay in. Any advice would be greatly appreciated. I have attached the pictures of fuse holder and amplifier.