I've been studying a lot of OTL headphone amp circuits but having a hard time accepting that big output capacitor. So I want to do something using an OPT. So I contacted Edcor about ordering OPTs from their XSE line but with a 300 ohm secondary to match my Sennheiser 650's.

EDCOR - XSE Series Output Transformers

Assuming you had a SE OPT transformer with a 300 ohm secondary to match your favorite headphones.... What amp would you build in front of it? I have some ideas but still deciding what primary impedance to get since Edcor asks that you buy a minimum of five units for a custom winding. Before I drop the dime I figured I'd find out what tubes and circuits people like for a transformer output headphone amp. Then decide which standard primary to get. Basically I'm letting the OPT and your kind suggestion dictate the path to take.

I’d like to build one or two small subs (6” to 8” driver) to be paired with DIY ScanSpeak 5F single-driver sealed sats. The crossover frequency must be above 100Hz. These are to be used in a very small apartment living room. I’m thinking sealed & powered subs. Perhaps one of the PE kits?

I’ve done this before with a PSB 8” sub using small sealed Role Audio speakers. The sub was vented & overwhelmed the Roles. (They never sounded right.) I then paired Bandor 50s & the 5Fs (separately) with a Yamaha powered sub. It worked, but it was odd in how it was configured & operated. I chose the 5Fs over the Bandors. The 5Fs are a lot of fun to work with if you love very small single-drivers, which I do, warts & all. The music I plan to play through these will be chamber music & small combo jazz.

Any ideas? I appreciate input on this.

Hi all
I would like to know how to test digital bass processor using oscilloscope. I gave 100hz signal and getting same 100hz output when turning wide and sweep has no change in the output. Is that normal?

I have Waycom Capacitors in my Trident 65 Channel Strips. I'm wondering if they are a good brand or should be swapped out? Thanks!

Hey guys covids got me eager for soldering stuff and drawing stuff on eagle.

One idea ive been wanting to try is nested opamp with discrete input & output in dip8 package. Looking around it seems like theres alrdy some like that coming out of china.

I bet they perform well, given the complexity of the architecture and especially if the mystery opamp is tamed for unity gain, allowing it to be versatile.

My idea for now revolves around 5534. Ltp input going into pin 1 and 8. Then output from pin 5 to a diamond buffer like ha5033 or buf634.

Is this a good idea?

Does anyone know how to teat a lm3886 with a multi meter?
Thanks

I finished reviewing the famous Philharmonic BMR speaker. It's way too much to copy and paste here (image tags kill me!) so here is a link:

Philharmonic BMR Bookshelf Speaker Review

I'm slowly, er very slowly gathering parts for an SSE build. George gives a Mallory part number and source for coupling caps, but mentions using Auricaps also. Would anyone here have a part number and source for equivalent Auricaps here?

Hello, all!
I want to paint my KRK Rokit 5 G3 woofers, from yellow to black or dark grey. Did some googling but couldn't find any tip. Also found lots of people saying it would ruin the sound. Is it really true?
Those are glass aramid woofers.




If it's doable, what paint should I use?
Thank you very much!

I am contemplating the restoration of a Lafayette Superheterodyne Radio - 1935.

But that's not what this post is about. This radio uses 2 x 47 pentodes in PP on the output. I may sound like such a geek saying this but they really are beautiful valves, so I got to thinking about building an amp with them. I have discovered that they are available here and there (even in South Africa). Does anyone have any experience with these valves? How do they perform sound quality-wise by comparison with more "modern" valves like the EL84 or EL34? Please let me know your thoughts.

(I searched but didn't find much about 47s on this forum)

Datasheet

If I'd like to upgrade the ELNA 1000uF 50v (of my Sansui SR-222 TT) with Mundorf MLytic caps, would it be ok replacing with a new Mundorf MLytic AG 1000uF 100V.
Is it compatible? Will it make a change on the sound?

Hi,


not the moment to ask postmen to carry such things, but I liked the idea?


Drop: Passions lead here (formerly Massdrop)



Is it a good idea to putt an OTL between a DAC and headphones (big ones) please ?


Thank you

In it's 100w + 2*50w 2.1 guise TPA3116D2 50Wx2 +100W 2.1 Channel Digital Subwoofer Power Amplifier Board P TTOW | eBay Can somebody definitely state if contains a high-pass filter on the stereo channels and if so what frequency is it at?

Here's an unusual "DIY" project:


Scientists Say You Can Cancel the Noise but Keep Your Window Open - The New York Times

Does anyone know what the original prices were for the Nakamichi PA300ll amps from the 80s?

I got some Monoprice xlr to rca cables would this work fine going from the Behringer amp to the mini dsp's rca's?

Monoprice 6ft Premier Series XLR Male to RCA Male Cable, 16AWG (Gold Plated) - Monoprice.com

I want to design an attenuator to step down from my modular synth signal level (~+-5V) to line level for input to my mixer. I want to get a quick visual of the level before plugging in to help protect my external mixer. I drew a circuit that seems to be working on the breadboard, but I would appreciate input on whether the audio path design is any good.

A few design choices:

• C1/R1 are intended to block anything below about 10hz.
• Opamp 1 is set up for -25% gain with R4 to fix input bias current.
• CX1&2 are to block above 30khz
• Opamp 2 is set up for -1 gain to correct the phase / R9 for input bias current.
• R15 is there, I assume, to protect the second OpAmp.
• The lower part is all from the LM3915 (mislabeled) datasheet.
• Not shown are two little caps next to the 5532 from ground to each rail.

1. Is this set up well for low noise and accurate response for an all-purpose range of sounds?
2. Does this take advantage of the 5532's low-noise design?
3. Is it okay to run the 5532 at 25% gain and do R4+R9 fix the input bias currents?
4. Should I move the pot before the first gain stage to decrease noise?
5. Could I reduce all resistor values to decrease noise?
6. Which capacitors should be polystyrene/etc. for sound quality?

In looking at the tube data for this device it list a gain coeficent of 20 +_ 4 . I assume this the same as the mu. But are they saying the gain varies from 16 to 24 from tube to tube or does the gain vary depending on the plate voltage .

I've been checking over a Uher VG 840 amplifier (part of the Uher Miniline stack) and would like some insight as to why the headphone output is not loaded by a resistor, and instead has a small capacitor to ground.

I thought this was normal to avoid untoward noises when headphones were plugged in when the unit was on, so I'd like to know what the designer had in mind here. I'm sorry for the quality of the snippet, but I've included one channel of the headphone output so you can see what I mean.

The headphone output is driven by an LA4170 IC, and the circuit follows the datasheet circuit which doesn't have a resistor.

Is the capacitor to decouple any high-frequency pick-up from the headphone lead?

Would I see any benefit from adding a load resistor in parallel with the headphone output?

Hi Friends,

I am making a Line Array with coaxial drivers. I just want suggestions on driver placement. I have attached 2 images ( placement 1 & placement 2)



With my limited knowledge i am sure many of us will agree that placement 2 is a clear "NO", but i need to know the reason behind that. I will be thankful if someone can explain me regarding this.


Regards,
Sadik

Some say yes others no!

What is your take?

Please state the reason for your answer.

I'd like to know the precondition for a successful PLLXO, like:
Pre-amp output impedance.
Power-amp input impedance.
Complexity of the x-over.
Etc etc.

Please jump into the fray. I'm listening.

My goal is to drive a combo of midbass/midrange woofer and horn with my Radford STA25 tube-amp and the 15" bass section with solid state or tube.

Sincerely
Kris

For reference.

i have a sundown 3500 that came in with shorted outputs, the amp was working perfectly but was stored for around 9 months, when the customer wired it back into the car it went straight into protect.
i have replaced all the outputs and the driver board, now the amp powers fine and when audio is applied it has a clean output till around 50% power then starts to pulse output on and off almost like it has audio then mute then audio then mute, if i turn the gain down the amp has clean output.
the only thing i have done different is replace the 1rfp360 with 24n40

Hi 🙂 , Im restoring a pair of THIEL CS2 speakers and sadly the VIFA stock ones are Blown. In my research trying to find the replacement for the stock model I got the Scanspeak 10F 8424g as the ideal replacement BUT they are too expensive. My other options are the 8 OHM FaitalPro 4FE32 and 4FE35 for less than half of the SS price.

Datasheet 4FE32: https://faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=401005100

4FE35: https://faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=401005150

Scanspeak 10F 8424g:
https://www.scan-speak.dk/datasheet/pdf/10f-8424g00.pdf

Would they work for as replacement for my Thiel's ??? Is there a better option??

Hi all,

I am hoping to repair a Seas G17 coax... marked as H0693, which has some tweeter damage (shorted coil). It seems to be a version of the H0723 T17REX COAX/F but with the cone in fibreglass.

The specs describe the tweeter as a 25mm, 6ohm part based on the H0615 25TFFN/G but with different housing for coax mounting. There are some references on the internet to a 25TFFN/X which looks like it may be the right part.

I'm looking for any suitable parts or donor speakers that I may be able to use for the repair. Information or advice also gratefully received!

I think that the suitable parts may be:
25TFFN/X. Seas 25TFFN/X (6Ohm)

or whole donor coax:H0489 P17REX/XF

• H0653 P17RE/XTVF
• H0723 T17REX COAX/F
• H0825 T17REX COAX/TVF

Perhaps this also uses the same tweeter?
H0487 MP14RE/XF


Thanks!
Daniel

The Rega Radio and Radio R and Radio 2000 (with remote control) were essentially re-packaged NAD 402.

For reference:

For reference.

For reference.

Rega Brio (one channel dead) - Page 2 - diyAudio

This amplifier design has an interesting history. It was originally designed by Texas Instruments (i think in Bedford England) as the "Texan" kit for "Practical Wireless" magazine back in the 1970's.
Rega borrowed the design but used more rugged output transistors than the original TIP41/42.

The main feature is that the output stage has some voltage gain which allows the op-amp to run off low voltage supplies.
I believe the original Texan design did not have quiescent current setting adjustment which can give the dreaded crossover distortion.

Hey crew - for anyone here in Australia looking at Primaluna tubes for their next project we've got the full range available with free shipping. To do one better you can join our email list for a solid discount on the RRP too.

All found here - PrimaLuna

Hope that helps! 🙂

Disregarding the cheap and corny sounding names for now, I got an email about these today.

Dayton Audio PSS545HE-4 Vortex 21" Pro Subwoofer with 5" Voice Coil 4 Ohm

Dayton Audio HTS545HE-4 Kraken 21" High Excursion Subwoofer with 5" Voice Coil 4 Ohm

At first glance these appear to have some value. Specs are very similar, maybe same motor and frame and just different soft parts? Klippel verified 21 mm xmax which is quite a bit considering most high xmax drivers are definitely not Klippel verified. "Unique over-excursion protection system warns you just before catastrophic failure" means this is a hard bottom driver. It's got a shorting sleeve but ridiculously high inductance.

Interesting but I have to check the data sheet and see what it sims like.

Wondering if there is a secure ready made harness available to connect 2 Chassis's (Chassi?) for a power amplifier. One enclosure will house the Electronics and heatshink, the other, the PSU.

I need at least a 3 gang / cable connection (prefer 6) that can be plugged in (screw type preferable)

Is able to handle 20amps sustained, and higher peaks. I have looked at Mouser... but I get lost in the tens of thousands of skus they have...

Any pointers would be appreciated.

I am new to this so please bear with me. Also I hope I can get some responses.

I had an AmazonBasics Bluetooth speaker with crushed woofers so I decided to use the card inside to make a better Bluetooth speaker out of 1 old Sony SS-EC50. It sounded quite good, but I quickly learned that it didn't get very loud.

One of my old teachers says I should wire the output from the Bluetooth card to a 3.5mm jack and plug that into an amp which then goes into the speaker. That makes sense to me, however, I'm struggling to find battery powered amps because I still want it portable.

Hopefully someone can help. Thank you in advance!

Looking for the value of the smd resistor R852. Its on the gate of the the FET that drives the little transformer for the low voltage PS.



Also, it appears this Fet is pulsed by a LM393 thru a MM74HC. What actually creates the squarewave?

Don't feel sorry for my dumb ***. I did the unthinkable. I purchased a set of speakers based on the fact that, I myself cannot afford a set of Klipsch Heresy used or new. So with a total budget of 100 dollars. I looked for a set of speakers I bought when I was 15, 26 years ago.
The Jensen CS 315. Well, those sell like hotcakes apparently. That whopping 20 bucks means they are gone before you find them. So I found a set of JHS 3315. The predecessor.

The owner kept complaining. "They are vintage". "Your getting a steal of a deal". "Are you sure?" I asked him. "I'm giving you 30 and everyone else is paying 20!". So after getting them home, I set them up knowing damn well that they had the same issues of the CS 315's had 25 years ago. No crossover, just 2 caps on a printed circuit board glued to a input cup. The 15" woofer was playing full range and drowning the midrange out. The midrange would poke its head up when A LOT of power was applied. As well as the tweeter would get uncontrollable. Let's go see what Amazon can do to fix this poopy problem.

Remember, my budget is 100 dollars. Total. I would use Parts-Express. But an Eminence crossover will put me to the limit. This may need mids and tweeters. So let the bargain shopping begin.

What I came up with was an Uxcell 3 way crossover. Crosses at 850/4000. Good enough. Stuffed polyfil into the boxes and installed crossovers. Still testing, but automatically the difference is night and day. I removed the metal grill screens off the tweeter and mid. This also made a huge difference. I might say now. They are respectable. But can still be better.

Looking now for a 5" midrange option. Should I stay closed back? Open back with an Eminence cup? Or spend a little more than I wanted and go dome?

So I saw this video yesterday and it got me thinking. How far have we really come in the last 100 years in speaker design.

1928 Western Electric cinema speaker - YouTube

Although it is to big a project for me to do currently, I am curious to know how much better we could make this speaker with current modeling, design, materials and drivers.

Wouldn't be interesting to see how a version of this speaker, using all we have learned would compare to the original?1

I got curious when I came across this statement somewhere on the internet as I assumed phase plugs are centred with the cone. Perhaps there is an advantage in having a small offset, for the same reasons one offsets a driver in a baffle. Anybody got any additional insight to share ?

“I recall, however, that Scott Fraser said that the phase plug mounts eccentrically in this driver, which made aligning the cone especially difficult. “

from: High Efficiency Speaker Asylum

Hi all, new here, ive managed to get a kicker zx1000.1 amp on the cheap as the gain toggle has broken, ive found a replacement part but they come in two values, just wondering if anyone knows the right one for this amp? The values they come in are 10k ohm or 50k ohm..
Thanks.

Hello all,

I am downsizing my parts stash and are making lots of precious items for sale. The first that I am looking to sell is my stash of Slewmaster v1.1 3P EF3 OPS PCBs. This was my favorite output board it works well! There are 10 PCBs in this package. The boards were professionally fabbed by PCBWay. How about $45 for the entire package? And please don't ask me to sell less than the described 10. Share with your friends! BUILD MORE AMPS!!

I just built a nice kit based on Kondo kSL M77 - schematic and photo of the layout here: https://www.lencoheaven.net/forum/index.php?topic=29419.0

I modified power supply for heaters using DC voltage regulator per this guide: This guide is to help you build the DOUK KSL-M77 Preamp clone kit.

After some tweaking of GND and Earth wires - using ground breaker, twisted input and output wires, optimal position and orientation of power transformer,... I managed to reduce hum to be almost not audible.

However one issue I have is the noise - I man white noise (not um, not buzz). Some observations:

- it is audible even 2 meters away from the speakers
- preamp is using brand new 12AY7 tubes (TAD)
- noise is caused by the preamp (I tried to use other solid state opamp based preamp and there is no noise then)
- it is audible with both phono and line inputs
- it is independent on the volume control - noise is constant
- I checked with microphone close to speaker and the noise has almost flat frequency spectrum - white noise
- it is audible also with line input selected (seems no problem with phono section)
- there are two sections in the line amp part of the circuit - schematics here: https://www.lencoheaven.net/forum/index.php?topic=29419.0 and when I remove the first tube in the line preamp section there is no effect - still the same level of the noise
- however when I remove the last section of the line preamp - “last” tube before preamp output (cathode follower - buffer?) the noise disappears.
- I tried also to change tubes - no effect
- I also tried to change the heather DC voltage from 12.6V to 11.5V and the white noise reduces a bit but it is still audible in the listening position
- the noise is in both channels

I fully accept that tube will have more noise compared with solid state - especially in MM phono preamp. However as it is audible 2 meters aways from the speaker and also with the line level input I think it is not ok.

Any idea what can be wrong? (Based on above observations it seems to be something with the last section of the circuit)

I am searching for some precision parts. Could you please post your favorite shops?

Hello all! Long time lurker, first time poster. I am not sure if this is the best place to post this. Please let me know if there is a more appropriate forum.

Here goes:

I am designing a board that will allow me to control my SCA-35 with my phone. The controller features 4 analog inputs and 4 optical inputs. The optical inputs feed into a DAC board that will be housed in the amp case. At the heart of the design is the ESP32 IC. I am using a rotary encoder for manual power and input selection and an Alps motorized pot for volume control. Before I have the board made, I was wondering if any of you would be willing to review my design to point out anything I missed or improvements I can make.

Any feedback you care to offer will be much appreciated!

Has anyone heard it? Madisound has a kit pair for $150. It uses the Alpair CHR-50, I believe. Looks interesting. Sealed.

Selling a pair of TDA1541A, previously used.
gold plated socket included.

€25 each or pair for €40

sold

Hello All,

I am new to this forum, I have seen so much knowledge has been shared in this forum in DIY stuff. I am planning to build a subwoofer with DA SD270A-88 10''. I have simulated the box with bass box pro. I have run the driver parameters and calculated enclosure properties. I have attached the file too please go through it and tell me if I am missing something. Thanks in advance for your valuable inputs.

I chose vented enclosure, I have seen some old thread related to the same driver but information are not complete, feel free to suggest me with different type of enclosure.

As I am new to DIY, please bear with my overnight knowledge.

Regards
Jeanpher

Hello, this is my first time posting here!

I’m thinking of installing a VVR from Ampmaker into my Vox AC4TV as I’d like to get some dirtier sounds at lower volumes. I’m not very experienced with electronics but I recently resoldered the connections on my telecaster selector switch, opening the thing up along the way, so I reckon I could put the VVR kit together without any problems. But I’m not sure if a novice like me would be able to install it in the amp itself.

I’m fairly technically minded and can follow instructions but I can’t read a circuit diagram, as yet. So I’d like to ask for advice from anyone out there who might have carried out this mod.

- How many steps are involved in the installation? I can only see three cables coming off the VVR kit - does it simply require three wires to be soldered in somewhere?
- Does anyone by any chance have something that approximates a step-by-step guide to installing this VVR with photos of the circuit board rather than a diagram?
- Is it possible to install the VVR and retain the AC4TV’s existing ‘attenuator’?

I am looking ake a headphone amplifier. Since op amps has limited current capacity I was wondering about output buffer. I wanted to use diamond buffer. I simulated a few output buffers and diamond buffer performed the worst.😡

I have been searching internet but could not find any article on how design diamond buffer, how to select bias current and driver emitter degeneration resistor. 😕

According Ltspice simulation a simple Push Pull is working better than Diamond buffer and paralleling op amp as unity gain buffer out performs all of them.

Simple push pull performs better with increasing the bias current but Diamond buffer suffers.

For similar bias current Diamond buffer worse than Simple Push Pull Circuit.

Tweaking current and driver emitter degeneration register does improve thd a little bit. But I am clueless as how to properly select bias and degeneration register for any given component.

Any assistance would be greatly appreciated.

simulation file included.

Hello,


I'm trying to generate a composite video signal. I had done this many years ago and it was working with an old TV with a 50Hz refresh rate. That is a 25Hz frame frequency and 625 horizontal lines. The circuit was very simple and it was based on 555 timer. Please see attachments. But now I want to make it work with a PC monitor and these have a 60Hz refresh rate. So, the question is how to adjust the circuit for 60Hz? I guess for the vertical sweep it might be as easy as to adjust the frequency with the trim pot.(?) But I can't find any info about the horizontal sweep i.e. the square wave shape. If you could enlighten me about all this or if you could suggest another circuit that works it would be great!

Hello everyone, thanks for reading my question.
I am working on an old Crest Audio 8001 amp. One channel is down and after taking some readings on all the resistors I am replacing all the faulty ones one by one(alongside other parts of course). There are a few on the PCB that I can not identify in terms what material (carbon, metal etc) they are made of as well as what power they would be. They are approximately 9mm long and brownish in color.

I am wondering are there any real significance of this at all ? Can I replace these with any type with of course the same resistance, tolerance and power ?

Being a high powered class H amp this, i would like to make sure I choose the right components and wont be let down on a 20p resistor. Your advice will be much appreciated !

I am attaching a couple of photos with the PCB the resistors in question are the ones in the yellow rectangles.

So, I was cleaning out old boxes for a recent move, and found an unbuild 41Hz AMP9 kit still in it's plastic bag. Was thinking of building it up and using it to repower the old 1965 intercom system in my 'new' house.

No paperwork with it, though.

What are the odds anyone has got some old pdf's for this thing? I know 41Hz is long-gone - and I found schematics on here for the AMP9-BASIC - but that's not what I've got. As far as I can tell, it's just called AMP9 Low Profile / 14.5V.

Hello,

Just looking for a pair of passive radiators to match the Purifi woofers. Hopefully I can find someone here with them.

Thanks for your help.

FS: Whammy headphone amp

For sale here is something I purchased not long ago, but haven't really used. Trying to clear some clutter and offering it up here.

The ballast resistors in my amp are JDC MPR 0.68ohm 5W ones. Its by a Chinese company. I am thinking of replacing it with better ones


Do you think Jantzen or Mundoff 5W metal oxide are a good choice?


Btw, if I use 10W ones instead of 5W, will there be any issues?? Just thinking that higher rating means the resistor won't be that hot.

Have this amp in, amp works perfectly with input voltage up to 13.2v after 13.2 the audio is muted. The amp remains on and power supply still supplies + and - 80v

Hello Gents,

The Sampan: ( The Sampan FTL ) has gotten a lot of very positive reviews. I'm wondering if there is a DIY equivalent design around. I recently have been listening to some TABAQs I built a couple of years ago and am greatly appreciating some of their virtues that I had forgotten about. I'm hoping that a Sampan clone will give me some of that quality of sound in a much smaller cabinet volume. Any information about a possible clone or similar proven design would be welcome.

Best,
Jay

Hi.
I added the photo of 5",6.5inch and 8" audax drivers with order.
Which one of them can I use a full range without any correction circuit and without any irritation?
I do not know which frequency peaks more important.
But I am guessing, it starts with 2-8khz??
What is the important thing, peak degree/sharpness or just the amount(db)?
I am guessing frequency response change wrt enclosure.??

When I tried to understand this graphic:
5" 5-6khz 6db peak
6.5" 7khz rising response
8" 2-4khz 8db peak and at 7khz rising response

But also I thing 5" has peaks at 2,7,10,15khz
How much are these important?

I prefer the full ranges with whizerless and changeable phase plug. (I learned from madisound, these phase plugs super glued)
But if it will have high frequency irritation, I can choose whizzer ones easily 🙂

The problem is i have binding posts such as those in following links :

https://hfc-fs.s3-eu-west-1.amazonaws.com/s3fs-public/jantzen-012-0170-binding-post-800.jpg

https://hfc-fs.s3-eu-west-1.amazonaws.com/s3fs-public/jantzen-012-0170-disassembled-view-800_0.jpg

they come with two star-like circles that i'm not quite sure what to do with.
Anyone knows what should be the correct sequence of nuts and those circles when mounting ? XD

Does anyone know of schematics for the Linn AV5103 processor. In particular I need to know the output voltages from the switch mode power supply module as I have one close to failure (capacitors leaking!) and would like to source a replacement.
Thanks, Robin.

Hi, can u suggest power amp drivers?

Smth that could safely operate at +-42 v, preferrably easy to find, not expensive

upc1225 is +-46 and dont know if it is safe enough to use with 42 v

Hi
There is a retailer on Hi Fi.Ru selling a piece of kit that I’m interested in buying but I would like some reassurance that it is a genuine shop and not a scammer. The shop is called OldAudio and is in the Altufevsky district of Moscow. The phone number is +79255076007.

Does anyone know of this retailer or can confirm that they are genuine?

Hi all,

Can AD1864 be replaced with AD1865 without any changes in an existing circuit?
In their datasheet it looks like they both have the same pinout and in the AD1865 it’s mentioned that they are pin compatible.

Thanks

Dear Friends,
I want to upgrade my cd player Sony cdp x779 es.Did anybody have such experience?

Can someone please identify this part please. I actually want to order the female plug to this part. I am calling it a 4pin audio out plug. It will allow me to bypass the small Amp on board. The config if it helps is R/G/G/L.

I have made single driver full range speakers and love them. But there are compromises and I'd like to explore adding another driver to the system. I plan to bi-amp so that the XO will be in the line stage (active or passive). And I would like to start my explorations with Open Baffle but would be interested in opinions to the contrary.

I see two options,

1) small full range (e.g. 4" size) + woofer (e.g. 15" size) with XO below the 'critical audio range' at around 300Hz

OR

2) large full range (e.g. 8" or larger size) + tweeter with XO above the 'critical audio range' at around 3kHz

What are the pro's and con's of these two options ?

I go to turn the Xilica on today and got a moderate pop out of the speakers and then nothing. Worked fine yesterday but today not a thing. The display briefly shows as normal and then goes to faint flashing or nothing or full display of every line in there in each space.



Hoping this is not fried but not optomistic. problem with Xilicas from day one is really crap documentation and information so hoping someone here has ideas.

Perhaps an odd topic for DIYAudio, but I really need to drive out this little critter!

- Tried flooding his hole / tunnels with water. Nope

- Tried spring traps from ebay - the mole just goes around them, eats off the bait w/o springing it.

- Tried poisoned peanut butter. Adams, the good stuff - I cant stop eating it. Just ignores them.

- Tried a couple of crap drivers (after reading success on the 'net: How to remove moles from your yard) wrapped in plastic, playing very distorted FM pop 24 hours. He just seals up his tunnels around the speaker - and makes new mounds within a meter of it.

Goodwill isnt taking donations, so I gave up getting rid of a Velodyne 12" sub I picked up there. (I'd use it, but it has a habit of coming on full blast with some kinda crackling noise at 3AM...) Maybe using a bigger gun?

He wont be able to just seal off the sound from that - hopefully. Trying the most obnoxious sound I could get from my FG, settling on a square wave sweep from 5 -> maybe 20 Hz - hopefully sounds like a stampede up there to the mole.

I've got the level set to a decent, hopefully non-destructive level. Heatsink gets hot, so I put a fan over it. The Velodyne immediately got covered in dirt and dust on first exploration of the idea, so I put down a piece of plastic and then a piece of rubber foam to get a bit better seal - to the ground. We'll see what happens.

Any ideas would be appreciated. Thanks.

Digi-key is selling mkps from 3 manufactures:

Panasonic - ECG
BC Components
EPCOS Inc

MKPs from them are cheap. But there're rarely discussions about these caps. how do they sound compare to, let's say, the same cheap MKPs from Solen, Dayton, etc?

I'm looking to build some small computer speakers for my Dad. They really can't be over 4" wide (the narrower the better) and about 6" deep. For height they can be 8-10".

I know I won't get much bass but I'm just looking for something that will be a step up from his cheap plastic speakers. Is there anything out there like that?

I'm looking for advice on considerations I should make when repurposing some items as speaker boxes.

Right now I am most concerned about selecting proper Vas and Qts. Is there a way to size this from the box size? I've only seen the reverse: box sized from these values.

For instance, last night I was trying my hand at this. The container interior dimenstions are 8.75"Wx11.7"Hx6.5?"D for a total of 0.385 cu ft (10.904 cu L). The front has room for ~5" cut out and a 1.5" tweeter cutout. The back I was going to replace (pegboard like holes) and either vent and/or put a (sub)woofer in.

Rightly or wrongly, I converted the Parts-Express woofer selection guide into a pivot table so I could sort and filter on Vented Volume, F3, Cutout, W_RMS and SPL.

I started with woofer
Tang Band 6.5" 4ohm w/ 50W RMS, 83 db SPL, 38Hz F3_vent @ 0.33 cu ft.

Tang Band 6.5" | 4ohm| 50W RMS| 83db SPL| 38Hz F3_vent @ 0.33 cu ft.

Filtering on box vol and cutout, I added this mid-woofer:
Tang Band 5.25"| 8ohm| 28W RMS| 88db SPL| 73Hz F3_vent @ 0.27 cu ft

Am I on the right track?

I've been experimenting with an all-tube headphone amplifier for a bit and have more or less settled on the 6gc5 pentode for power out. It prefers B+under 200vdc and I'm particularly fond of the punchy sound. Triodes using the same B+ supply wind up with 70-120v on their anodes because of my plate resistor choices. (depends on tube, bias and resistor value) I'm really satisfied with the sound as-is, but it's leaving me wondering if it would be even better if I could be giving the tubes more of what they want, you know? Are there any good twin-triodes out there that perform their best (or thereabout) within that voltage range? I've tried 6FQ7, 6EU7, 12AT7 and 5963 so far. Some give specs for my voltage range but the tube specifications state that such voltages are far from optimal. Admittedly I may be reading them wrong though. I'm also picking up a boat load of RF from the audio source cable. I can easily hear everything that my bench PC (audio source) is doing. Hi-mu triodes seem to exacerbate that but I'm going to have to take measures to stop it in addition to using a shielded enclosure and cables. Maybe bias the front-end cold to lower gain and/or use medium mu triodes? I'm not sure. As-is, it has a pretty stupid amount of headroom so lowering output isn't an issue whatsoever.

Want to Buy:



Please drop me a note if you have one available, even if you're not in the US!
I'm located in St. Louis, Missouri, USA
Thanks!


Tom

I have a Napa Acoustic 208A AKA Mistral DT 307B hybrid integrated, with a pair of 6N1 in the pre. Napa Acoustic is no longer in business. Only the right channel works. Only the right tube lights up. And I have swapped left and right tubes, no change.
I have opened up the unit and checked the electrical connections. Is there an internal component that will fix it most of the time? Troubleshooting this is not in my skill set. Switching out a component is.
Thanks,
Joseph

Hi everyone, I'm trying to design the footswitch for my new three channels amp, but I'm not sure how to pull this off. The amp has three channels: I have two relays that takes care of the channel switching. When they are activated, they will switch to clean or lead. When these two relays are not connected (i.e. the GND is lifted), the amp is in the crunch channel. Channel switching is currently controlled by a three position panel switch and this works just fine.
In addition, I also added a post FX loop additional master volume which is controlled by its own dedicated relay to GND. I would like to have all this switching in an external pedal: normally I make two channels amp, so I can get away with a simple stereo jack. This time, however, I want to be able to switch between the three channels (clean/crunch/lead) and turn the loop on/off as well. I figured I could use a 5 pin DIN port to transport all the signals I need, but have no idea what's the easiest way to wire this up without using microcontrollers or PICs... Do you guys have any suggestions? I'm a bit lost 🙁

Can you test these driver ic’s like you test the 21844S ?

Wondering since these ic’s are in a taramp I’m working on and the rest spraker thumps a few times and amp goes into protection

For my active speaker build I bought 2 of these:

Sure Electronics AA-AB35281 3x200W Class D Audio Amplifier Board - T-Amp

but even when nothing's connected, it's noisy.

EDIT:
Using a Connex 600W SMPS: SMPS600RS | Connex Electronic

I need advice on either how to make it silent (Don't think that's an option - but hey, if anyone's got a magic tip I'm game 🙂),
or advice on decent class D boards to provide individual amplification to my drivers.

I'm building a set of 3 way speakers, using a tweeter, full range driver, and subwoofer driver (TB 1139SIF).

I'm not looking for club volume levels, just casual listening - so the tweeter and mid don't need much watts. The 1139SIF might need some oomph since it's 83dB....

I noticed 3E Audio used to have a 3-way amp:
TPA3251-3CH-200W | 3e Audio

but I contacted him and it's out of production...

Any recommendations on decent class D amps I could use for this setup?
(A 3-way amp like 3E's would be awesome but my Google-fu has turned up zilch..)

In several retailers there are selling the closeout VOCOPRO FeatherAMP 500W for under USD$100.-

That amp uses the ICEpower 125ASX2, which can be used in stereo (125wpc@4ohm) or BTL (450w@4ohm).

The amp also comes with gain knobs, a design that can be used as a plate amp, a 1/8 TRS pre amplified input and also balanced input.

The VOCOPRO company is California based, so I would assume they used genuine ICEpower products.

I am kind of wanting to buy it to power my Auralex bass shakers or maybe another subwoofer.

So... is it a good deal or not? What do you think?

Looking forward to your replies and comments.

Does anyone know what the socket type used by Wondom on their DSP and programmer is called?

I'm designing a DSP board myself and would like to use same socket ...

Thanks
Baldin

P1020754 — ImgBB
P1020741 — ImgBB
Hi there, I got this Motorola SC-320 AM radio turntable combo from Argentina.
Radio works for a while, then it shuts. Turntable moves and stucks.
I want to try to fix it but I don't even know what I see.
Any help?
Has anyone seen a similar Motorola combo? I need some basic instructions on how this things work so I can check it out a piece at the time.
Where's the amp line in? How could I feed it another sound singnal to test the amplifiying system?

Thanks in advance.