I have some replacement parts that have a little larger leads on - can I just remove all solder (as much as I can) and then open up with a slightly larger drill?

Thanks,

Not sure if I can post this here, but I figured if anyone online had some knowledge on the topic, you guys would.

Capsule was exactly 1m away from tweeter, centered on the tweeter. They were measured on their stands in my studio control room. I know you're supposed to position the driver halfway between floor and ceiling and side walls before measuring, but these are heavy, and the stands are huge.

Monitors are Barefoot MM35 Gen 1. I had the amps serviced by barefoot this spring when I first noticed that the right monitor sounded different in the midrange. They said it was most likely the amps. But it didn't fix the issue. The dip starts right around 2.5k, which is the crossover frequency.

I should also add, in the past I switched cables, sides of the room, covered every variable, and the measurements were all close to the same: right monitor dips in SPL right around 2.5K.

hi all,
I came across a couple of cheap ul sowter output transformers 100watts. n=22, so 4 ohm speakers would reflect to 2000 ohms. I was thinking using a quad of 6l6gc (ra-a=3800) in parallel push pull to kind of match the impdedance. When i draw the load lines, i find them steap though. Is this an okay choice? just would like to get some input from you guys. Thank you.

Regards, Daniel.

VINYL SALES SHOW STRONG INCREASE AS DIGITAL MUSIC SALES CONTINUE TO DROP

Approaching 10 million albums sold in 2017

Hlw am new here..and my English is not good

I want to build an amp like that of a car with 12vdc as input voltage

I just want to push a 100w amp for sub ( already made) and two stereo amp for mid and high i.e two lm3886 for mid and 2050 for tweeters

Can somebody help me a circuit for power supply that can supply over 300w

Any one with any suggestions

Need help identifying this tube.
Dual triode, tests in same slot as 12bh7/ au7.
Thanks for looking....

Hey all. I just have what I am anticipating to be a couple quick questions. Some background to begin with: I have an old Peavey PA-900 mixer/power amp that I'm planning to remove power amp from, leaving the preamp section for recording purposes. Given that, I'm working on building a lighter-weight power supply. There is only one DC source to the entire preamp section so I can see that I'm working with around 50vdc and 50mA current draw. Best I can tell each channel has a couple transistors working as voltage regulators so I don't need to build a regulated supply. I have experience with tube amps, but when it comes to solid state circuits, things are done a bit differently and I feel a bit out of my element. Hopefully you guys can help.

Questions:
1. Is a simple supply like the one I've drawn up and attached below sufficient?

2. I've noticed on the current supply that there is 0.02uf ceramic cap across the transformer secondary leads, what does that do and is it necessary to replicate?

3. Similar question (function and necessity) for the 0.1uf cap in parallel with main filter cap to ground.

and...
4. Are there any basic safety features I should add?

Thanks in advance for any help!

For sale: custom built left, right, center (identical to right) 4Pi speakers with upgraded B&C DE250 compression driver and JBL 2226H woofer. Built with ¾” MDF and finished with matte black paint.

I used them in my home theater for a couple years and then used two in a stereo pair after moving to a smaller place where I didn’t have room for a full theater. I am now putting them up for sale since I only need stereo and don’t have space to warrant speakers of this quality. They’re in excellent condition and have never been driven even close to their limits.

Asking $1500 (OBO) for all three, pickup in west Los Angeles. I will ship them on request but they’ll probably need to go by freight given the size.

Hello every one

Please see my audiophile hard drive (well that's what I call it) its a 1TB western digital black hard drive with suspension. I also made a high current power supply to power the drive .. I use it to store my WAV music files. I wanted to make a hard drive look like a piece of hifi equipment and be reliable as possible. I also added side mounted heatsinks to keep the unit cool. The drive is nice and silent once the lid is on .... what do you all think?













all the best

Nick (jamesfeline)

More info will come to the website in short order, but the official dates are April 24/25 this year.

Please let me know if you can attend!

Thanks,
Wolf

Hi,
I was wondering if anyone knew where to source the 17,000uf 55v capacitors that appear on the power supply pcb.

I have searched, but cannot find the ones in the correct package size, they all seem to be 2.5" diameter.

Many thanks

Diane

I love my coffee grinder but it's extremely noisy. It's a Baratza Sette 270. I have other coffee grinders that are much more quiet -- pleasant sounding, actually -- but they are designed for commercial use so not good for single dose passthrough. The nice sounding grinders use steel enclosures.

Because I think the grinder is worth it, I want to build a noise reduction enclosure. I'm not sure how I'm going to approach this yet so I started by trying to measure it with REW.

If anyone has ideas on how to approach a noise reduction enclosure I am all ears.

Now that I think about it, I should probably measure the nice sounding grinder so see why that one is ok. I'll do that later and post the results.

What Player program Do you Recommend on Android for Best Sound Quality Playback?

Hi All


On Android, the app HiBy Music is describing itself as
"A HiFi audio player featuring USB out"
and "support for direct USB audio on Android 7.x" (and above, I assume)
and is used by many people.
HiBy Music - Apps on Google Play


But on Android, there also Foobar2000, which is so prefered by many people, on Windows PCs:
foobar2000 - Apps on Google Play

And thre's also VLC for Android:
VLC for Android - Apps on Google Play


So from these 3 apps, which one is most prefered?
Does the last 2 apps also have the Direct USB feature that HiBy Music has,
or it's the only app with this ability?


Thank you

I just bought this pair of boards which implement a clone of the Marantz MA-9S2. They're all assembled and look more or less like the picture on the vendor's page at Wholesale Product Snapshot Product name is Assembled 150W+150W HIFI audio power amplifier clone Marantz MA-9S2 AMP C5200/A1943 free shipping. Each board is one channel.

Although I think I understand pretty much what to do next, I am getting the feeling I also might be in over my head as this is my first amplifier project, close to the first thing I've done with analog electronics, and the first project which requires that I build a power supply from parts. I am really just starting to learn and so there are gigantic gaps in my knowledge. I'm hoping that finishing this project will end up allowing me to banish at least some of the major gaps. I'm confident I can eventually puzzle this thing out, but would sure appreciate some help!

I understand that each of these boards wants a nice toroidal power supply to give it around 25v DC, so I figure I will get this toroid: 300VA Toroidal Transformers and then hook each output up through a bridge rectifier like this: Wholesale Product Snapshot Product name is KBPC5010 Bridge Rectifiers DIODE RECT BRIDGE 50A 1000V, followed by a capacitor or two for smoothing--that last part I'm less sure of how to do right since I am starting to think there are probably some important subtleties.

Does it sound to y'all as if I am more or less on the right track? I also still need to figure out where to attach things on these boards. The places that look like attachment points on the board, followed by what I think they're for, are:

GND: to be attached to the earth from the wall power

-VSS: to be attached to the negative side of the DC power

+VCC: this must be the positive side of the DC power

a pair, one of which is labeled INPUT+ and the other is unlabeled: this must be the audio input


OUT: One speaker wire must get attached here, but where's the other wire go? Does it get hooked to the same GND?


Okay, that's where I'm at now. I will probably end up searching down some books on power supply design next, and order the toroid as above unless with your help I figure out that that's not the right one.

Oh yeah, one more thing: I am also going to need to figure out how to add a volume adjustment knob/knobs. From my initial reading it looks like a voltage divider circuit might be the thing, but I'm just starting to read about that and would very much appreciate advice or pointers.

I feel like there is probably a book which I should read to tell me a lot of this stuff. If there is one that folks here would recommend, I would love to find out what it is.

Whew!

Hi everyone

I’ve just got the above CDP for a reasonable price. After studying the design, I came up with some ideas for modification as follows.

1. The analog and digital sections share the same power supply. I plan to insert a new power supply for the digital section with a separate transformer. This is straight forward.

2. The player has 4 dac chip AD1860, two for each channel in parralel. Here I plan to convert the configuration into dual differential. The design utilizes the internal opamp for IV. I am not sure on some points here:
(i) to convert from parallel to dual differential some suggest to invert the data line for one of the two DA chip in each channel and then replace the external analog stage with a pair of line level transformers. IV is already done inside the chips. Does this scheme actually work?
(ii) for the analog stage using 1:1 transformers do I need to terminate the primary or secondary windings? If yes what is the recomended resistor value? I plan to use some Edcor 600:600 that were left over from other project. I think I may need to lower the Vout from dac chip by adding an extra resistor in parallel with the internal resistor of i/v too.

Any comments or suggestions are welcome. I have included part of the schematic.

I have one of the little guys and need another one, hopefully someone has one to sell!

Peerless S-508 OPT

I'm looking for helping choosing an appropriate constant current source for a discrete op-amp preamp I'm working on. It's a 4mA tail current source for a jfet pair that goes between the jfet source and the negative 15v rail. Obviously a resistor or current limiting diode is the simplest solution. I've also looked at some circuits using a TLV431/transistor/resistor combo but I would have to figure out how to implement it in a negative voltage circuit. I was hoping some of the wizards here can provide some direction.

Hi
I purchased this pcb off ebay with no info
after studying the tracks i have managed to get it working and it sounds very good
i am using a MM cart
the pcb has a switch on it which is shown in the schematic sketch i have drawn
with the switch open the sound is clear
when closed sounds dull and no top end
am i right in saying the closed switch setting is MC ??
mistake in pic the feedback is connected before the 4.7uf output cap

20201126_134152 by glenn jarrett, on Flickr
20201126_134106 by glenn jarrett, on Flickr

Hi, I have a diy 12 inch sony xplod subwoofer which is quite good for my 14ft x 14ft room. I have a creative x-fi sound card and I run 7.1 speaker with CMSS and audio crystalizer on.

For a more cleaner range of bass I want to add a second subwoofer. Should I go for a 10 inch or another 12 inch subwoofer?

I want to build a subwoofer and the Devastator came up on a google search. I know nothing about audio and don't really want to get into the details. I have a great room that is 25' by 25' and vaulted 16' ceilings. I play a lot of pipe organ music that has a lot of bass. Would the Devastator be a good choice or would there be others that you could suggest?

Hello! Came here to learn about this audio equipment I found on the curb near my house. I'm planning to post to my local CL as a bundle and see if I can get a couple hundred dollars for everything.

I appreciate this great community y'all have, so if you see something you want let me know. Please consider my time and effort in hauling home, posting photos, and primarily shipping. I don't need to make money on the effort, but I'm not here to lose it either. 😛

google drive sheet of major components. some other smaller things like remotes and a speaker are not listed here as they are not worth anything.

imgur album of everything

I have a set of beovox 5700 speakers and I believe the capacitors may need changing/ upgrading.. does anyone know the exact ones to purchase they are the beovox 5700 6254 version. I am looking to put speaker ports in the back aswell and replace the old cable hanging out of the back of the speaker. Thanks In advance if anyone can steer me in the right direction.

I am building a σ11 power supply from AMB with 12 volt output and reading up on the input/output AC wiring the recommendations are a bit confusing. One site specifies nothing less than 1.5mm2 (16 AWG) while another specs. .14mm2 (26AWG) which seems too small to me, but the wire on the transformer speced by AMB has 0.75mm2 (18AWG) on both primary and secondary. I am thinking that the AC cord and any wiring after the secondary should be at least .75mm2 (18AWG)....a bit confusing.

Anyone have a bit of guidance on this?

Has anyone used or have any thoughts on using the kind of PVC sheeting used to protect table tops etc, to construct baffles or cabinets? It's very flexible and seems to damp/insulate sound quite well. It could be formed into smooth curves for waveguide and rounded edges to fight/use diffraction to advantage.

Will the 540 and 9540 work in place of the SS264 SS236 for the outputs

Hello, first post here. Wondering if anyone has a clue where I might find a remote control for my X0.2 preamp? I've searched everywhere I could possibly think and have came up empty handed. Any suggestions would be greatly appreciated!!

Does anyone know of any builds that would work with a Visaton FRS8 as a full range single driver computer speaker? Thanks

Using the middle tab as ground reference here is what I get

Q2000:20.30
Q2001:-18.93
Q2012:voltage is get pulsing up and down
Q2010:-13.71

Could Q2012 be defective or would something else cause the voltage to be pulsing leg 1 is -13.37 volts put leg 3 is where I get the pulsing voltage

Hi there,

Here is my latest project: a small(ish) lab supply.


I already own a number of supplies, both commercial and DIY, but I felt the need for yet another one: the ones I have so far are pretty bulky things, and they have a fixed location in my lab.

• I wanted something lighter and more portable that I could move anywhere on my bench, and use like the physical dead-ringer of a spice voltage source: completely isolated, floating, agile and electrically perfect in all respects.
  
• Initially, I settled for a modest size: something like 40V and 200~300mA.
  Then I thought it would be nice to reach a bit higher and pushed the voltage to 60V...

Looking for a suitable transformer, I could only find too small ones, <200mA, which was really too small, or a larger one allowing up to 500mA.
You can easily guess where this ended up: the usual specs creep...

The supply I finally built was three times as large as originally intended, but it still qualifies as a "small" one.

• It is a relatively traditional linear supply, with all the features you can expect for such an instrument, but it also has some unusual characteristics: it is exceptionally clean, quiet, stable and well-behaved. It also has a very minimal output bypassing, meaning the energy it can deliver to a load that is brutally shorted is absolutely minimal.
  This slightly impairs the transient response, but it is always possible to temporarily add supplementary caps, whilst the opposite is impossible.

• The circuit is relatively complex, but this (moderate) complexity offers some advantages: voltage and current are variable from zero to the maximum, without the need for auxiliary supplies or similar impediments, and there is no shunt in the ground's way, meaning the circuit could very easily be used in a bipolar supply without complications.
  The no-load power is also extremely low.

When in standby mode, the current and voltage set values are displayed.

All the components are very common, cheap and easily substitutable.

Here is the schematic that will be described later, and some pics of my finished prototype:

⚠The revised version of the schematic can be found here⚠

...if you had a very large room and didn't mind sitting really far from the speakers 😀

I want to sell some C3G tubes - SIEMENS. They are new - NOS and NIB in original packages.
Price 49€/pcs + shipping. I have 16 pcs.

What pins do I jump on this to make the amp play full range since I don’t have a module for it ?

I'm a longtime audio gear-head, but I am also a librarian at a design school, and for the first time, have a work related question.

There has been a speaker design project at the school for the last couple of years and I would like to buy some books for the students on how to design them. They design the speakers currently for looks of a desktop system and I am not sure if they even sound good, but I would like them to design it so it will.

Also, I would like to find some good books on simple diy audio project related to amps and preamps as well. Does anyone have any suggestions?
These students don't have time to dive into electrical engineering so it would have to explained in a simple way.

Thanks!!

I have a pair of Ampex 6973 mono amplifiers, can I sub the 6CM6 for the 6973. I have noticed adapters on eBay for such a sub.

Bohlender Graebener RD50 Repair Question

Greetings! I have a pair of the BG-RD50's, one has some open foils on the diaphragm. If I were to open it up to attempt a repair, does the force of the magnets push the opposing frames of the driver apart or pull them together? Will the magnets stay in place while separating the frames?
Thanks in advance, if anyone can please help me out.

Well here the story
My fat cat named Chubbs was on top of my newer pro-jet turntable ( essentials III, all analog, well hit kicked it down and it took a 4 foot drop and did not make it. I’m was so pist
Well my wife said I can buy a new table, has to be under 650. And ideas on what to buy?
I don’t need and fancy bells on it,
I was looking at a music hall mmf 2.3
But it looks a lot of a pro-ject made table that has been rebranded as a music-hall.
Hell I’ll even buy used from someone here
Thanks

Hi,
I am in the process of recapping my Threshold S/300 and need a 47uf axial capacitor.

I typically use Elna Silmic II series, but they don't make an axial.

I was thinking about using the following bipolar Mundorf cap, since there are not a lot of axial options intended for audio applications (none on Mouser, for example):

(ECAP50-010) - 47uF 50V Mundorf ECap AC PLAIN electrolytic capacitor | Hifi Collective

Any issue with using a bipolar cap here?
Any other suggestions of a better choise?

Much appreciated.

Brad

In https://www.diyaudio.com/forums/sol...d-mosfet-amplifier-wireless-world-1982-a.html I mentioned that the Hitachi circuit posted by Nigel reminds me of the BUZ-Amp from a Siemens Appnote 1982/83. Very similar amps were published in France and in a German electronic magazine. Here is the simplified schematic: "Siemens-BUZ-Amp.pdf".

What I like about this is the simple 2-stage design with only 2 LTPS, and no VAS. It needs no compensation apart from 2.2pF over the feedback resistor since the dominant pole is the output mosfet's input capacitance. Since I once ordered a small batch of boards and had some left, I wanted to try a complementary output. This only needed a current mirror to invert the drive for the lower P-channel FET. With both source pins towards the output now, I re-arranged the 1k resistors to include the 0R22 bias resistors. They are there anyway for the U/I limiter (not shown for clarity, neither thermal compensation, Zobel, etc.). What came out is seen under “BUZ-Amp-N+P-MOS.pdf”.

Why it resembles the Hitachi circuit you can see in "BUZ-Amp-into-Maplin(Hitachi).pdf".
It has the advantage of a push-pull drive to the output FETs, and the bias is adjusted there (since it has no current sources, only resistor tails for the LTPs). As shown (also in the link at the top with the original schematic), it is only suited for lateral FETs (V-FETs = runaway bias).

It occurred to me that something originally designed to drive two N-Channels might also make a simple circlotron: "BUZ-Amp-into-Circlotron.pdf". The big question was what to do with the feedback? Taking it from one output node only like in the picture does work somehow, but it does not look right to me.
A way around was to take (negative) feedback to the input as well, and keep the positive feedback connected to the negative input of the first LTP like before: “BUZ-Amp-into-Circlotron_2xFB.pdf”. This actually worked, sounded good and with a pot at one side of the LTP the output offset could be adjusted too.
This was one more example to make a circlotron with only one (ground referenced) input. Most circuits you see posted have either two inputs, or opamp front ends.

Next idea is to make a symmetrical input, with IN- feeding into the bottom of C3 (instead of going to GND). This would make it fully symmetric. But will it work? What do you think?

Hi,

does anybody have a link to the above article or a copy they can share? I believe it was published in 2011/2012.

I'm writing up my new phono amp and need to reference his design since the topology is similar.

Cheers

This is no GNFB amp, the gain part is a current conveyor and output stage use Only Distortion Negative Feedback (ODNF).
The gain is set by the P1/R9 ratio.
Distortion was lowered at 1 kHz with ODNF from 0.036191% to 0.000323% (40dB) and at 20 kHz from 0.037325% to 0.006647% (15dB). I am not sure what is the reason for that low improvement at 20 kHz, could be the OP amp used in ODNF or I do something wrong here. Comments and suggestion welcome.

I made a new amp, described here.

It is my twist on McIntosh's Unity Coupled output design. I would love know what you guys think.

Hallo, I have owned this preamp for many years and these days I wanted to use it after many many years of rest.
After making the correct connections the right output channel both in balanced and unbalanced does not work ... it is mute, both with mm and mc connections.
I tried to disable/able the mm switch and mc several times thinking of an oxidationbut to no avail.
is there a possibility to get a schematic diagram?
What may have happened?

Thanks for the attention.

They are 8 inches in size and most likely be a Philips because the box has a badge on the back. I can't find a way to safely remove them and check the back of the speakers to read the letters.

Is anyone familiar with these?

I am trying to get them sound somewhat acceptable, so far i have failed with all my amplifiers.

Before two years I made an amplifier without soldering in signal path, just in some places, where I wasn't able to avoid them. Last month I upgraded it... for this two years was working without any problems. There wasn't any loose connections, or something that shows that there will be future problem.

Connections was made with connectors like this, I don't know their English name:

http://www.diyaudio.com/forums/attachment.php?attachmentid=604976&stc=1&d=1489357376

First try was with the original iron screws. Now I put also brass screws, like the material of the connector.

The reason was that before few years I made few same E88CC preamps, each soldered with different soldering wire... all was sounding different. Then tried solderless... it was also very different, but very smooth and clear tone, much more natural than others. The best sounding soldering wire was lead-free Furutech... can't remember the exact model. After that I made the first amplifier in that way...

Maybe many of you have tried it on interconnects - soldering vs screw connection? All that I have read before is, that the screw connection has better sonic quality than soldering connection.

For sure, it can't be such reliable as soldering connection, but for me, the gain in the sonic quality is enough big to do it so.

I will be happy if someone else have also tried it, or try it and share his experience.

Regards.

Hi,
some time ago I decided to back up my files in the Google cloud. I'm running WIN10 Professional. Since then nearly anything on my SDD has been mirrored to the cloud automatically. By now Google has shut down my gmail account, 'cause my 50 GB data space has been exceeded.
What do I have to do now to get gmail access again, but don't want to pay for additional memory space? How can I prevent random upload to the cloud?
Best regards!

Hi
This simple amp was repaired (change the IC in one channel) at a friend of mine repair shop. It works pretty well, put out 102W on resistive 4 ohm load, clipping is perfectly simmetrical, and sounds pretty decent.

Now I intend that offset is controlled by the IC, but how the 35 mA bias (measured) is fixed?

I am looking at a 3 way speaker kit which is a large 3 way stand mount.
What I would like to do is reduce the width from 310mm to 250mm and increase the height to make it a floor stander.
Maybe I would even increase the volume to get more bass and alter the port tuning I am pretty sure I know what to do in that respect but what I am not sure about is baffle step correction.

The design I assume includes baffle step in the crossover but by reducing the width it changes the frequency at which it occurs.
My question is will it affect sound quality and would I hear a difference or would it not matter.
I believe crossover from bass to mid is at 500hz.

Hi Fellas!

Movies like No Game No Life, and the Project A KO films are all made on composite 480i s-video. This would prevent an actual HD release.
How many other films/shows are affected.

I feel sad.

I was thinking, if you applied a sinewave tone burst to a bass reflex sub at the port + box resonant frequency, depending on the Q of the setup, the air inside might take several cycles to get up to full amplitude at resonant frequency, and during this time the cone would have a much greater peak to peak excursion than it would at continuous tone because the air inside the box wouldn’t be loading the cone very much.

If we do a spectral analysis of an otherwise pure sinewave tone burst that starts abruptly at the zero crossing we find that there are harmonics present. But if we have, say, a 30Hz tone burst and we low pass filter it at 60Hz then we find the signal starts rather more gradually. It doesn’t get to full amplitude in the first quarter cycle but grows over several cycles.

So the question is, if running near full power, would a tone burst that is not low pass filtered be more likely to drive a woofer too far? Or would the harmonics, seeing they are of a higher frequency, simply not move the woofer cone as much anyway?

Hi all,

I've been looking for a macOs replacement for rePhase (which is amazing) but have come up with nothing. I can write a bit of python so started looking into writing a script to create the FIR coefficients I needed. I'm only really interested in sharp angle filters and shelving - not EQ.

I have put the code in this repo:

GitHub - geowal19/GSFIR

Current functionality is extremely basic and only a proof of concept. I have implemented a way to create brickwall filters and shelving, I have no tested the coefficients in real life.

Please feel free to clone and play with the code, there's a demo script called tester.py.

I will be continuing to work on this in a very casual basis.

I have around 10 of these E130L - anyone want them @ £5 each? Collect only.

Does anyone have one they would like to sell?

Thanks.

How would one mod the classic CMoy portable diy head amp project to output, say, 1-w. Say, for high-Z 'phones or otherwise non-sensitive cans?

It seems a seller on eBay has done this.
audeep CMoy model I - 1 Watt portable headphone amplifier US POWER SUPPLY BUNDLE | eBay

But how? Especially in a portable chassis?

Most if not all schematics and posts that talk about UL/Triode mode switches have been SE amps.. I have only seen one site mention moding a PP to add this functionality.

Does, or can a push pull amps characteristics be altered the same way?

Pluvia7HD is best cost performance driver at 4" full range.
Music of all genres is played good sounds.

















7HD sound at YouTube
Enya 7HD - YouTube

Hi all,
I hope everyone had a nice Thanksgiving.
A while back, I picked up a pair of vintage early 1990s Radian 12" coax drivers #5012, no crossovers.
AFAIK they have the 450 compression drivers, 1" aluminum, same as many other Radian coaxes from 8" to 12".
For testing, I mounted them in 2.8 cf ported enclosures (some of you may recognize what they were...).
So all day yesterday, I was messing around with different different inductors, caps, and resistors using many alligator clips.
I felt like this morning I got 'in the ball park' and hardwired everything, as to eliminate the alligator clips that definitely hurt sq.

This is what I've arrived at so far, it sounds really good, but I'm sure it's not perfect yet, so I wanted you guys to look over it:









Continued in next post...

Hello everyone,

A while ago I slowly started to learn about electronics and especially audio. So far, I've made LM3886 (powered by 24-0-24 toroidal) (still without case) and it is powering some old Magnat 20cm (8") car speakers.

I don't know how exactly the quality should sound but so far it seems not bad for me.
For fun I've tested TDA7377 amp which I got from old car stereo, connected it to 12V toroid (~16VDC) and at my usual listening levels I could barely feel the difference and it even reached quite high volume.
I've measured the RMS Voltage across the 4ohm load, the max power before distortion was about 4W. To compare, my LM3886 can give up to 65W.

For my future goal, I’d like to make audio system in living room, 2 speakers neat TV (probably towers, powered by LM3886) and 2 at the back, still wondering what driver should it be, but I'd like to use my 12-0-12 toroidal. And by how I hear it, I feels like I could just slap 4 more powerful 4 channel car audio amp and it will be enough.

Now the question, since such low power can power these speakers pretty well how much power would the living room (size 5 meters x 4 meters) would need? Also, since most speakers have more than one driver, I should consider this fact as well. And furthermore, there are some very sensitive speakers, some people even use high quality low power amplifiers and are happy.

This seems like there are too many variables and how can one solve it? I would like to hear how people of this forum solved this problem and how you did it in your beginning of audio electronics.

TL'DR I have LM3886 and recently tested TDA7377, used 20cm (8”) car speaker, TDA which is much lower power compared to LM and it sounds loud enough for room. So how do you set the audio system in your room and how to calculate how much power do you need? How the power gets distributed to proper multi driver speakers and how to include the sensitivity and size of the room into calculation?

Eddit: Applied bold

Hi all,
I have had my current speakers up and running for a few years now. They are Bigger is Better cabs with some 8"x10" Alnico Isophon drivers and Alnico Isophon helper tweeter. I love the sound of them and am generally very happy with how they perform. Early on I Mass loaded the ports to tighten and tidy up the choppy bass.

The thing is I listen to quite a bit of electronic music which has tight deep bass, and quite frankly the BIB goes deep, but not tight. Other than that I just love the sound of the Isophons. I have a pair of 10" Isophon woofer, which I was contemplating trying to mate with a nice pair of Foster FHT-5 tweeters, but last time I tried that with some big Tannoy's I failed. I really don't want the misery and expense of tunning a crossover from scratch. So I thought - why bother when I have some really nice full range speakers which do almost everything perfectly.

So my idea is take the tuned Isophon combo of Fullrangers and helper tweeter and mount them into a aperiodic box. This will probably lead to a smooth drop off of bass from about 500hz down, but should let the Isophons breath adequately. So I have been messing about with the idea of some TL's for the Isophon woofers. My idea is to build a set of TL's with the Woofer firing vertically into an Aperiodic box. the box is vented on all four faces ie back,front and sides. the aperiodic vents will take care of rolling of the 7K response to meet the top Aperiodic box, and should be easily tuned via the aperiodic vent stuffing. The back transmission line can be tuned to take up where the vents leaves off. I have included a sketch to help you visualise the concept.

So what would be the advantages of this approach;
-the top aperiodic box would be easily tuned and optimised independently.
-the aperiodic TL can be tuned independently, and the TL response can also be tuned independantly.
-because the aperiodic TL is firing from all four faces in phase it should take care of baffle step losses.
- there are no inductors in the system so phase shift and inductive loading of the amp should be less of an issue.

As usual this is purely a thought experiment at this stage and so I may have missed some essential reason why this whole idea just won't work, but i would appreciate any input on this idea.

Shoog

Hi,
I am trying to put my td160 back together and I lost the screws that mount the tonearm board to the sub-chassis. Does anybody know what size they are?
Thanks,
m

Hello All.
I have a 12 VDC to 120VAC power inverter I want to run with a LioN 16/20VDC battery. The inverter can only take 13VDC Max. input voltage. What is the best way to reduce this batteries voltage to 12VDC while still maintaining maximum current capability.
The power inverter will be powering a 140W bass amplifier head. I have another identical battery I can hook up in parallel if necessary but I want to see if one can handle it. A low value High wattage resistor in series?
Thanks.

I'm considering a speaker system using one wide box with separate enclosures for two full range drivers and one sub.

This is only the second speaker system I've ever built, so, i'm still a bit green. I'm wondering if anyone can give me advice as to weather or not the following components would work well together. (included are their specs)


Any feedback/criticism is highly appreciated!
---------------------------------------------------


FULL-RANGE (2 Speakers-stereo)

• MODEL: Dayton Audio RS100-8 4" Reference Full-Range Driver
o RMS: 30 watts
o 8 ohms
o Freq. Response: 90 to 20,000
o Sensitivity: 84.6 dB 2.83V/1m
o Resonant freq.: 92.2 Hz

These two full-range drivers would be pushed by a 2x15 Watt 4 ohm amp.





WOOFER (1 mono speaker)

• Dayton Audio DC160-8 6-1/2" Classic Woofer
o RMS: 50 watts
o 8 ohms
o Freq. Response: 30 to 4,000
o Sensitivity: 86.1 dB 2.83V/1m
o Resonant freq.: 35.7 Hz

o Crossover: Low-pass 100Hz 8 ohm

This woofer would be pushed by a 1x30 Watt 4 ohm amp. It would also need its only level adjustment. (VOL pot)

---------------------------------------------------------------------


My questions:

-Would these speakers work well together?
-Is the crossover frequency selection a good one?
-Are the speaker watt and amp outputs OK for each other?
-Is there anything i'm missing here? haha..


Thanks in advance to any input!!

Recently I ran across the schematic for the QSC RMX-850A. This is a factory-built present-day amplifier for which the manufacturer publishes a schematic! (Thanks QSC; please never change!)

It's a really cool architecture in that the power rails swing along with the output rail -- go check it out. The only discrete transistors are drivers and outputs, the whole frontend is an op amp. There's no large capacitor in the negative feedback loop, so it shouldn't thump at power on, so we don't need an output relay for civilized behavior.

There's not much to go wrong, and not much to rebuild if it does.

How accurate could an amp with an opamp frontend be? Could we reduce distortion to the single-digit parts-per-million range like the best discrete amps, with a low parts count like the QSC and with no output relay?

Op amps present two challenges:

1. Internal compensation. You may wish to use a 2nd order compensation (TMC or TPC) but you can't delete the op amp's internal compensation. That can limit 20kHz feedback and thus limit distortion performance.
2. Supply and output voltage limitations, typically +/-15V for many op amps.

We can solve both issues with one strategy: keep the opamp output voltage nearly static in-band.

Here's a rough draft of such a circuit. Its distortion floor is about -106db into 4 ohms at worst. Gain and phase margins are healthy, whether measuring at the OPS output or at the op amp's output. I'm not sure the bootstrapped VAS current source is great for avoiding power-on or power-off thumps; that might have to be a real CCS in a finished design.

The design uses TPC for 2nd-order loopgain roll-off, it has >70db of feedback in band. It works well (in simulation) with a high speed, unity-gain stable op amp. It doesn't work well with an LT1115 "audio" op amp; maybe that one has complex internal compensation that interacts badly with the external compensation?

Open question: is it possible to reach the same accuracy without a discrete VAS, using only an op amp driving a CFP output stage as the QSC does?

Hi,

I'm selling a pair of these wonderful tweeters!

For details see: AudioExcite - For Sale!

Best regards

/Göran

****** The tweeters are sold ********

Another power supply I am in the middle of creating. This one is for my Wayne Colburn BA2018 Linestage build. This PSU is much smaller than my previous one and uses more modern regulators.

The PCB measures 160mm x 100mm and is designed to slide straight into the rails of a Hammond 1455T2201 enclosure. Just waiting for the boards back from the fab house.

Just a few specs:

- Ultra Low Noise and Ripple thanks to a CRCRC filter.
- Full Bridge rectifier with X2 rated snubber cap.
- Enable feature to power on/off regulators with switch while leaving rest of board powered.
- Low drop out regulators with built in protection.
- LED indicators on the rails to show board has power and third LED to show ON state.
- Adjustable voltage from +/- 5v to 20v.
- Max current upto 1A dependant on transformer.
- Onboard fuse on the mains supply.

I will get a board built up when I get them for further testing.

I have pair of 9710’s and they play beautiful in a TQWT enclosure. I am building a second large open baffle system and four big units is a bit much. So I thought building a second but smaller home for my 9710’s.

I am not a expert and there is so much written about these speakers that I get a bit confused.

Now I found a perfect looking speaker and I wish to build something like that. It is the Hoyt Bedford 1.5 tower, this is a BR enclosure with the following size

H27”68.6cm W11.5”/29.2cm D 11”/27.9cm as said I like the look and dimensions but I have no idea if this would work. I don’t have the knowledge or software etc.

I am open for suggetions, maybe changing the dimensions a bit, I even thought about a mltl with the opening on the under side (no idea if that would work but in my head it looked nice…)

Hi,
.


I'm looking for a pair of 2SB206 transistors



Anyone help ??


Andy

Alright, new project, dubbed 'Valhalla'. It is to be a floorstanding loudspeaker, about 6 feet, 1.80m, tall. It'll use eight (!) SB Acoustics SB17NBAC35-4 woofers in a impulse compensated configuration. A FaitalPRO 6PR160 mid and the legendary Beyma TPL-150 AMT compliment the woofers.

Here's a few 3D sketches of the drivers, and the first attempt at a design. I'm going to model the entire loudspeaker in 3D first, to try different design ideas so I can better visualize what the loudspeaker will look like in reality.

Comments and suggestions are welcome!

Sorry. I know what you're thinking. Not another NAD hum thread ( : But please bear with me for a second.

And apologies. 1. Taking pictures of an ancient scope is not something I do very well. 2. Amp was bought like this hoping it would be a quick fix. Not entirely so unfortunately.

Here's what I see on the speaker terminal. Scope is set to 50mV, so there abouts that on the output:


Anyway - onwards and upwards: Standard issue hum from both channel. Fixed level so I could just turn up the volume and then I wouldn't notice. No change depending on input selection or volume.

Started by replacing the main caps in the power supply for the power amp. No change. Then replaced all caps in pre and power amp and pre-amps power supply. Same same.

So pulled out the old scope and started measuring. Ripple on the power amp PSU: (scope set to 0.5v). Not super great but ok'ish for an old NAD: (sorry for the offset, scope wasn't zero'ed in)


At this point, I didn't suspect the pre-amp PSU, so I disconnected the signal cables between the pre and power amp (no pre-out/main-in on this). No result - still humming along nicely.

Then I started looking more at the schematics and noticed that +41.2v and -27v from the pre-amp PSU actually goes to the power amp and I'm definitely not smart enough to come up with a good explanation as to why NAD chose this solution:

Pre-amp PSU:


and power-amp schematic:


Since I'm not smart enough to figure out why they would do so, I figured I'd try to remove the fuses for the pre-amp PSU. Now I'm not sure if this completely shuts down the power-amp part, but it certainly killed the hum.

So the hum is definitely coming from the pre-amp PSU (in my head at least), so put the scope probe on that one: (Scope still set to .5v)


Considering there's about .10v ripple on the power amp PSU, this seems quite excessive - like something is pulling much more juice than it's supposed to. To pressure test that theory, I re-added the original 330uF/63v across the new ones:

Well. It's a result, but a band-aid on an axe wound (and the amp is still humming 😉 )

So I guess my theory is (somewhat) correct. There's a much larger power draw on the pre-amp PSU that the designers factored in. Could be the power-amp since we still have +41.2v and -27v going from the pre-amp PSU to the power-amp. So removed the fuses from the power-amp PSU hopefully shutting it down - the ripple on the pre-amp PSU stays the same so I guess the power-amp section is ok.

So either the circuit in the pre-amp PSU is gone haywire('ish) or the pre-amp section has. However, sound is absolutely fine. Sinus curves looks pretty much spot on too.

Any pointers as to where I should start to poke with the probe from the old oscilloscope (which I sorta borrowed when I was an apprentice - which I finished in 1996. I love old stuff that still works today) or what I can check next?.

Thank you - and apologies again for another "NAD, now with extra added hum" thread.

Does anyone here know of where I can find or download a service manual for the Agilent/HP 339a ?


A google search has revealed a few links including Agilents website, however upon downloading the PDF the quality is too poor to read the parts list (its like a very poorly scanned document).


Any help would be much appreciated.
Thx.

Hello

Is it possible to find a schematic over this Riaa.
Allways like to have schematics.
Thanks on forehand’s

Many years go I was given this old Acutex cartridge. I stuck it in a drawer for use as a spare if my current cart. gave up the ghost. I currently use a Shure V15 type IV that I bought new way back in 1978. The Acutex has a nice tonality but lacks detail and upper frequency reach compared to the V15, makes it sound a bit dull in comparison. There is no model number on the cartridge only made in Japan on the top. It is fitted with a conical stylus tip. From my searches on the web it might be an early M106, but I'm not sure. I would like to get a replacement stylus in the hopes that it would improve the sound. Can anyone here provide a positive ID, and can an elliptical stylus from a M110E fit to provide more detail ? I have included some cell phone pics.

Thanks

Hi,

I've just bought some of these Soviet Valves, attracted by the fairly high gain, or similarity in some aspects, to KT61.

Has anyone here experimented with them?

Any advice/designs/recommendations, that you could share?

TIA,

Greg

Is it wise to use a dummy load when testing a preamp? If so, what resistance would be correct?

Help which 10" woofer I chose out of these 3 SB or Alcone Or Visaton ???

Hello

I would like to ask any opinion from those people who used or heard these SB woofer in 3 way system or as a sub-woofer.
I want to use it in a 3 way system in a 75L BR enclosure.
AudioNL store
Another option I think about the Alcone AC 10 HE
Alcone AC 10 HE
These is the Visaton
Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories
Visaton produce some of my favorite drivers all do I never heard these driver
Any pro and contra welcome before I buy.
Thank you very much🙂

Greetings Gabor

Hi All,

I am Mani from India. Happy owner of Yamaha NS 1000 Which is currently driven by Yamaha AX 900.

Recently I had issues with Yamaha Tweeters and Woofer due to the aging (yeah its 40+ years old) and magnet juice are reaching the End of Life.

Once I have replaced the Yamaha BE Tweeter on left ( purchased online) and Midrange too. Since the replacement drivers are old too I no longer have thought of replace them with originals.

As all know the Yamaha NS 1000 Cabinet solid build ,planning to replace the Woofer,tweeter and Midrange once they stop working, frankly speaking we cant ask more with 40+ years drivers anymore. My dream is to replace some quality drivers to justify the cabinet without much work.

1.Morel CAT 308 replaced the BE Tweeters, the sound quality has dipped still very decent sound I get from these tweeters.

2.One of the Woofers Magnet ,Hence I have ordered Dayton DC 300-8 12'' Woofer which should fit within the cabinet without any alteration.I am Yet to receive the woofer to install and see if the money is well spend on the woofer to match atleast to certain level of Original woofers.

3.The Midrange are fine working and I am looking for a decent replacement without breaking bank.

I listen average and above average volume and more in India Music and Progressive Rock.

DIY Forum has helped me to escape from nightmare when I think about aging Speaker 🙁. Successfully i have rewired the drivers for one Speaker with 16 Awg for Woofer and 18 AWG for Midrange and Tweeter.

Any suggestions for the Midrange are welcome also let me know any good replacement woofer in case Dayton DC 300-8 is not impressive.
😉

Good day, tubers!

I've done a lot of reading on this forum, very informative. This is the first time I've posted to any forum, ever.. so if I am posting in the wrong section, or doing something otherwise incorrect, let me now.. I'll rectify the issue.

To the matter at hand.

I will be constructing an amplifier based on the infamous Mikael KT88 SE schematic that seems to be a favourite schematic to build. I want to used KT150 tubes. My knowledge of electronics theory is limited (relating to valve tech) but I'm confident with a soldering iron, as well as following basic safety guidelines.

I've collected most of the primary hardware (PTrans, Tubes, Tube Sockets, Motor Run Caps, Chassis) but I will need some guidance from you lot, who's collective experience is a huge asset. I'm not sure where to start with my questions, so I'll just start..

• Will the 6N1P have enough output voltage to drive the KT150's to a reasonable level?
• If the 6N1P doesn't have the drive.. can I incorporate a 6SN7 preamp stage into this design? (I'd love to do this regardless)
• Would 3k Hammond SE OPT's be appropriate for this design?
• Are there any obvious changes that I would need to make to this design in order to use KT150's? (I've thought about making a selector switch to allow the use of KT150/KT88/6L6)

I realize that this beast will require a PT with substance, so I purchased a Hammond 378CX. I'll be going with SS rectification. I'm guestimating around 300ma draw, maybe more.



Let's get the ball rolling.

Cleaning out.

The following are only $2 each:
Dayton Audio xovers
2K-LPF-8
2K-HPF-8
2K-LPF-4
3K-LPF-8
3K-HPF-4
4.5K-LPF-4
4.5K-LPF-8


Of course... at this low a price you can remove and use the coils and caps as you please...


Air coils (also $2 each):

0.36 mH 0.37ohms
0.416mH 0.28ohms (on blue board with 10W resistors)
2.1mH 0.78ohms
0.64 mH this is the one on the 2K-HPF-4 board shown missing capacitor

For $10:

1.00mH 0.30ohms Janzen Audio 15 gauge, PE price $17.48 part# 255-422

Price plus shipping from 47150. Prefer cash, but will accept Paypal if you pay the fee. Minimum order total $10 plus shipping. Will be posting many other things in the next week or so, mostly just little odds and ends including free stuff.

Hi

I got to thinking about the acoustic effects of a mesh in front of the drivers.

If the mesh is 1mm metal and the holes are 4-5mm the effects are probably minimal ( as this is standard for many PA-solutions).

But what if the mesh was much thicker? - say 20mm? and the holes were Ø30mm? I'm guessing the holes will have an resonance somewhere in the audible spectrum. Below resonance the holes will make little difference, - as long as airflow is kept below turbulence. What happens above resonance?

I'm wondering if the holes could be tuned to give a boost over a (small) range?

Most of all I'm curious 🙂. Hornresp can do a lot, but I cannot figure out how to put this one into HR.

Kind regards TroelsM