Hi I got a Sony ES amp with some bad scratches on top of te front panel is there a way to fix this?

Attached is a LP section of either a 2.5 ways or a 3.5 ways speaker. To calculate for L3, I’m curious whether the speaker W1 could be considered as a capacitor, so the calculation can follow standard third-order formula.

Or are there any means to calculate L3 except using simulation softwares, i.e., VituixCAD, REW, etc.? (I can use them but just curious if there’s an alternative method, even hand calculation, available.)

I'm watching this guy on YouTube that repairs all kinds of audio stuff, and came across this:

Login to view embedded media
I'll let the video speak for itself, but I must say I'm shocked by what shoddy circuits anyone can put together and sell for ridiculous price tags.

... I was lost in a new (to me) forum. Just looking for now.

I used to enjoy playing with affordable low end stereo stuff in the '80s. Since then I gave all my vinyl away and re purchased some of it on CDs and today play ripped copies on my laptop. None of the old hardware exists. Not sure where my re awakened interest will take me.

Cheers, Russ

Hello Ive been learning allot about healing frequencies. 432hz. 528hz etc

But Im really confused by all the youtube videos with "earth frequency" 8Hz

No speakers can play this low. Whats up with all the videos?


How do I make a speaker play this?




Thanks

The post that I started last Wednesday on current drone sightings has been shut down by the Moderators. I assume that was done due to the rather silly and somewhat derogatory comments that were being made by some posters.

But this is an important and timely subject. And it is completely nonpolitical. People on all sides of the political spectrum are concerned about it.

So, I would like to continue a serious discussion here and ask that it not be corrupted by unnecessary silly comments.

========================================================

As of now there are still no definitive answers by the government or anyone else.

More sightings continue at a high rate and in new places not previously heard from.

The sheer number of drones that exist in the US alone, almost a million accounted for and probably an equal number unaccounted for, makes this a very serious matter. I don't think people realized until now exactly how many of these drones exist. And more are being manufactured every day.

This issue is not likely to go away soon and seems to be certainly worthy of a respectable discussion here.

Hi Guys,

I'm trying to build a phase splitter for a tube push pull amp, i only need about 2v p2p swing from this and I plan to run it off the negative bias supply, thus NPN rather than PNP. Any advice how I can improve this circuit? Priorities are PSRR, symmetry then distortion.


Cheers!

I have a broken Sony GTK-XB5 speaker, the electronics are broken and one of its woofers too, my idea is to use a woofer and a fullrange to make a smaller self-powered Bluetooth speaker.

I thought that if I took the volume of the box and split it in half and did the same with the length of the bass reflex tube I would get a box that sounded the same but smaller but trying in WinISD I have seen that this is not the case, and I do not have the thielle-small parameters of the speaker.
I have a 3D printer and a calibrated microphone. My idea was to make a box with half the volume and try different bass reflex measurements until I got the desired response, but I don't know whether to start with the same diameter or a smaller one.

How would you do it?

Hi all,

I have this amplifier in protection. I have noticed the power supply caps are leaking.

what are the correct mosfets for the psu / output sections?

the amplifier was previously repaired

Hello,

I have a Rudistor RPX-33MK2 headphone amp which is producing noise in the left channel. The noise comes on a few minutes after the amp is turned on. The channel still works, but the static noise is just there along with whatever is playing. I've recorded a sample of that, which can be heard here - https://app.box.com/s/7htgpg3ieiuytt61qwhsd5ux05i3b0bf

I wanted to ask for some advice on how to go about resolving the issue. I can see the trimpots, maybe need to adjust those but have little idea where I would point my multimeter to..

Any tips are most appreciated, would like to put this dude back in use 🙂.

Thanks,
-Art

Hello All,

Very much new to understanding this program.

I'm trying to understand how to get loaded B+ measurements at output transformer with using the Vta st70 as a template. Mine is the same power supply section besides transformer to the Dynaco ST70 attached schematic.
transformer is 360VAC @350mA
output transformer is 4.5K
I'm running 6l6gc output tubes and 6ns7's on the driver board.

When loaded With a multimeter its got about 440vac at C1, 430vdc on the plates of 6l6 with 40mA bias and 375vac on the driver board B+ which is correct to the Octal schematic

Attached is a screen shot what i have so far which seems like Ive done something wrong
So, Is the B+ voltage for output transformer read from the V(R1) RMS? C1 voltage isn't 440v

Help is much welcomed 🙂

Wayne

I'm planning to build a speaker, but I want to build something different - thinking outside the box (pun intended). I'm planning to build it out of either 12mm or 1/2" birch wood plywood. Maybe you guys have better ideas on construction materials. I drew a rough sketch of what I thought might work good (open side-view attached), but I need you professionals to give me the exact dimensions that would work best - or just tell me if the design just plain won't work.

I am a professional amplifier engineer, and my goal is to accelerate the transition of audio to green.

Hi.

Dave here.

I lurked on here to build a headphone amp a long time ago, and have been back lately as life changes a bit.

I just built some of the redux amp camp amps. They came out really nice- using them to drive some speakers in my shop. Not the most powerful but sound alright, and it keeps the neighbors from getting too upset about volumes and my lack of control. 🙂

Main listening is currently a simple system; Bluesound Node as streamer / DAC, Naim Nait XS, with ProAc 2.5 Response out the end, with Naim cables throughout.

I'm thinking about building more because it brings me joy, so I'm now posting and getting started. (And learning is such a great thing.)

So, thanks for such a great forum.

Dave.

New to this forum, I tinker with electronics and audio crap, I collect cassette tapes and players, and I dabble in vinyl.

I thank you very much for lettin’me in.
I am an audio aficionado and also a reviewer in two Italian Magazines called AudioReview and AudioGallery.
I pretty much follow electrostatics threads as this kind of loudspeakers mean so much to my passion for music and audio.
Thanks again.

Hi all, I've already learned a lot from this forum, but I'm now out of my depth and hoping to get learning again.

Just have a few questions on wiring sub to amp. And sub enclosure recommendations for home audio. First off I have a Skar EVL-12 DVC 4ohm and a BASH 500 plate amp, I don't know how to correctly wire these . Being a dual voice coil sub I don't want to wire it wrong and damage my amp. And yes I know this is not the best speaker for home audio but it's what I have. Also is a car audio enclosure different than home audio? Finally any recommendations for a box builder program that works with mac.

Hello everyone, 🙂

I’m currently training as a cabinetmaker, and I’m working on a project to build a Leslie/Doppola speaker inspired by Dürer’s Solid (https://en.wikipedia.org/wiki/Polyhedron_of_Dürer). I also plan to design an electric guitar to match this amp. This post focuses primarily on the technical/electronic aspect of the amp (the guitar being a separate project). My goal is to create a Doppler-effect amp for electric guitar.

After some research, I’ve encountered a few dilemmas:

• Should I go for 1 or 2 speakers in my amp? Would this improve the sound quality?
• Should I faithfully replicate a Leslie cabinet, or consider a simplified design that might be less expensive and easier to build?
• What would be the best setup for guitar? Should I be inspired by David Gilmour’s Doppola, or go with a single-speaker configuration and rotating baffle? It seems to me that the Doppola has a less pronounced effect compared to the Leslie cabinet.
• Where can I find all the parts needed for this project? (My idea is to start with a tube DIY amp kit that I can assemble myself.)
• Where can I find schematics or plans for similar projects? Or even other specialized forums for this kind of project, perhaps?

I’m a beginner in electronics, but I’m passionate about this subject, and this project seems perfect to start learning. I will surely post updates if the community is interested (about both the amp and the guitar).

For now, I think a simplified version, like the Doppola or a design with a single speaker and rotating baffle, would be the most coherent, although the original Leslie cabinets are legendary… 😍

Thank you in advance for your advice and suggestions. I’m open to any resources or feedback on similar projects!

P.S. I’m French, so I apologize in advance if I make any mistakes in English!

For sale, a pair of Altec 902-8B compression drivers with original 34647 aluminum diaphragms, 8 ohms. Also includes gaskets. Great Plains sells these for $850 each or $1700 for a pair. Asking $400 net, plus shipping. Please see my ads for Altec items.|

For sale, a pair of Altec 816As loaded with 515-8LF woofers, 8 ohms. Only driven on Sundays - they came out of a church in Ft. Wayne, Indiana. Asking $1,000 net, plus shipping that you must arrange or pick up from the Cincinnati, Ohio area. Please see my ads for Altec items.

Hey DIYAudio!

I've been a long time lurker of the forums for over a year now - I've caught the speaker-bug & it's consumed most of my free time. Dreaming of a big stack of speakers - putting on unique events & connecting people through sound.

I met my wife on the dancefloor at a unique bass music event in Canada - music has always been a core part of our relationship. We talk about how the event we met at is no more - & where would we meet today of we were that age again?

The desire to curate high quality events surrounding connection through art & sound, quality food & non-alcoholic beverage has me seeking the best possible sound I can possibly create.

Im a builder & do everything myself to the highest quality possible. The level of professionalism here has me excited to be a part of this community.

Recently I've assembled a Maslow4 CNC - working out the kinks to be able to consistently & reliably cut cabs & delve into scenograhy is the goal.

The works of Tom Danley & Tony Andrews are inspiring & how they continue to move the sound world forward is incredible.

Located in the Okanagan area, BC Canada. Very keen to bring something good to the sound world.

Look forward to collaborating with the lot of you!

-Scott

Hi.
I'm working on this GAS PSP2500.2DF amplifier (made by A/D/S, model APA21700DFB. http://www.adsaudio.cc/webs/carAudio/detail?id=1000111 )
The amplifier always turns on in protection mode.
On first start, a PWM pulse is given in the power supply, which charges the rail capacitors to +/- 50VDC. If you disconnect the remote and reconnect it, the PWM pulse in the power supply does not appear until the rails are discharged. I have checked both channels and they are correct, I have even replaced the 2092 ICs. I have also checked the power supply control board and everything seems to be in order.
Has anyone had a similar problem?I hope I have explained myself well.

Thanks.

Hello,
For my new project 4 channel amplifier SA2015 (Bi-Amping) I will also make speakers protection with large mosfets in (TO247). These protections are usable up to 400W.

They work reliably in my SA2014 amplifier (400W/ 4Ohm).


schematic:


pcb layout:


PCB colour: blue
Thickness of copper: 2 oz

Closing on Sunday (24.11)

Hi.
Anyone got a scematic for this excellent Sub amplifier?
I have No sound, relay do not turn on, No voltage to relay. No DC on output either. All opamps looks ok when tested separately.

.

I have 10 of the mentioned driver at home and planning to build enclosures for them for a movie theater system. I can't however find any parameters for them or really any info at all apart from that they have been available in a diy build kit from now bankrupt Finnish audiostore HIFITALO.

I tried contacting the peerless company but got no answer. Does anyone have anymore info on these or a clue how I could get the parameters I need to design and build a enclosure for them

Is Curcio Audio still around? Any where to get the ST70 and power supply regulator boards? Have some made?

As per title, and like these please from hifi collective.
Thanks.

Hi,
I recently got these 3 way tower speakers from my godfather and when I connect It to my amplifier only the middle was working, I've tried it with a Technics SA-EX310. I've tried it also with a Kenwood KRF-A4030 and the issue stayed the same. All I know about these speakers they were used long time ago.

also here all the specs that I could read of the speakers:

• Long term power: 100w
• short term power: 170w
• frequency range: 50hz - 20.000hz
• impedance: 4 - 8 ohm

I also know about the technics amplifier It can be used with because it supports 8 ohm speakers.
I also heard that these speaker have a poor crossover and It might need a better one. I really don't know how I can replace it by myself and what kind of circuit bord do i need to buy, but the speakers worked before without the crossover change so I don't think It's necessary.
Sorry If the answer is really clear but I only got this far

Adam
Odorheiu-secuiesc

I saw an amp I've been looking for some time... it's on Mercari.

Has anyone bought anything on that site?

Gautier Capucon played Shostakowitch's Cello-Concerto N° 1.
We (wife & I) were right in front of him, ~4 m away. Wow.
It reminded me of a concert of the Who (never saw them live though), he kinda wreaked havoc on his instrument, unbelievable.
Near the end, the 2nd string gave up and jumped off the board, but even this didn't stop him. (A cellist from the orchestra wanted to help out and gave his cello and the conductor had to keep it until the end)
Had no time and no occasion to take a picture.

I'm looking to build myself a good set of speakers to replace my Focal floorstanders.

I do a lot of joinery work including bespoke cabinetry so building the cabinet from scratch is not a problem, hence why I don't want to waste money on pre-cut cabinets that come with some kits. I want all of my outlay/investment to be on drivers and crossovers.

Amp wise I am currently running a Michi X3 which has a max output in class AB of 350w/ch into 4ohm and 200w/ch continuous into 8ohm. At some point I will no doubt start to experiment with pre and power amps and no doubt tube amplification.

My musical tastes are eclectic but I would say mostly - Alternative, Prog, Kraut, Psych, Electronic, Folk, Reggae & Dub, Hip Hop/Rap, Rock some Jazz and Classical.

A member recently introduced me to SEAS kits and their drivers do seem impressive. Has anyone built any of their speaker kits or could anyone recommend one?

I am interested in the Delling, Thor, Acuity and Aphel from the quick read I have had....any thoughts?

Hi ! watching some videos on Youtube about high priced small speakers in the comments often someone points out the fact that they use songs with limited frequency response i.e. little bass
for example, one asked why in the demos of small two-way speakers they never use songs like Bach's Toccata and Fugue, if anything, by raising the volume a bit
One answered because otherwise they destroy the speakers
I wonder first of all if this is possible
after all a speaker should be able to reproduce all the music at a decent level with good quality
Does this mean that these small speakers have strong intrinsic limitations ?
I saw a small monitor that costs as much as 100 kusd/pair
If someone puts Bach on and raises the volume, does he risk making it smoke ?
is it possible? if so they should warning the customers

New here, just sharing some info, repairing audio gear/etc

Hello everyone!!!
I am writing to you from Italy, and finally after a long time, I am about to start the construction of my final audio system (at least for a while)!

I would like to present the project, and ask you as well as your opinions, some advice...

Ready, go!

The room is 4,3x10mt big, the system will be placed on the narrowest wall.
At the end of the room there are stairs going down, so it is not enclosed. The roof is built with wooden beams placed crosswise, relative to the placement of the system.
The thermal insulation of the house was made cork, which could also help with the sound.
This Is the room:



I have always been fascinated by the sound of horn loaded systems, and after much thinking and many doubts, I am finally coming to a concrete final idea:

Three way, fully horn loaded, multi amplified system.
Bass with Radian 2216 neo driver, loaded in spiral box as designed by inlowsound:
https://inlowsound.weebly.com/spiral-bass-horn.html
Double mid-bass with b&c 8pe21 driver, again based on inlow design:
https://inlowsound.weebly.com/135-hz-mid-bass-horn.html
Mid-high with Radian 950pb driver, loaded on Arai 290 horn:
https://www.araihorn.com/p/arai-290.html?m=1

As a preamplifier I have my eye on a model from Black eyes audio, tube with integrated dac:
https://blackiceaudio.com/daccd-pla...p_mzEsxKOnnsQ6TQI1Z-rqfXn0mVFk4z7O3LGaK6aC_vI
For the crossover I like the dbmark series:
https://dbmark.co.uk/products.php?i=XCAX
For the power amps I wanted to install class d amps made by IcePower, models and power ratings to be determined.

Indicative cutoff frequencies 130Hz/600Hz...

You will carry out the construction by me, and calibration together with a friend....

I am looking for a very dynamic and very exciting sound, but one that does not fatigue the ear....
I would like the frequency response to be as even as possible throughout the room....
I would like to have great quality both very low and at very high volumes...

Here is a picture of the possible arrangement...



Let's move on to the questions:
My first idea was to make a four way system, and supplement the Radian driver with a tweeter higher up...
Given the problem of the distance of the emission centers, I decided to let the Radian driver do all the work up to 20KHz, but I have no idea how it will behave on the higher frequencies, like above 12Khz...
The changes introduced by Arai on its horn, compared to the Tad one, should give me a good off-axis frequency response even for the higher frequencies...
Has anyone had a chance to test this aspect of this driver? How do you think it will perform combined with this horn?

Also regarding the Radian driver, is the 8ohm version or the 16ohm version preferable?
Also the issue of dual mid-bass is to be able to have the most consistent frequency response possible across the width of the room, and so I should match 2+2 horns...
The designer told me that this horn has great punch and matches the bass very well, and that's exactly what I'm looking for....
The problem is the off-axis response, and I was thinking of solving it by doubling the horns....

How would you amplify the horns? Drivers in series?
Given the stability of the 4ohm amps, also parallel drivers?
Or even better, get the crossover with 4 outputs and put in two power amps?

I'm also a bit worried about tube preamplification....
Let's say I would like to give some warmth to the sound with preamplification, but then I would like to have the sharpness and control of a class d on the power amps...
I wonder how much sense this would make?
My friend who will help me with the calibration claims that we can use the crossover to create the kind of sound I want....
If this is feasible, I could easily opt for another non-valve preamplifier....
What do you think?

All opinions are welcome, thank you all very much, and Sorry for the english

Top pair of basmid units in verry good condition. Verry good T&S parameters. In 40L netto volumen enclosure - 3dB 34Hz.I sell only zhe drivers, no enclosure included!!! Shipping worldwide but the price for 200 euro for this pair is including shipping price only to EU countrys. Payment is Paypal for friends.

I'm building class-G amplifiers (which I mistakenly labelled as class-H on the silkscreen - sacre-bleau!), which stretches my lab supply capabilities.

Normally I use an pair of old Thurlby PL320 supplies (nominally 0-32V, 0-2A), which I tweaked ages ago to do 0-40V, 0-2A. They don't do enough current to actually start testing amps though, so once I've done the initial setup and smoke testing I generally substitute a +/-40V or +/-56V unregulated supply.

It's not ideal. I'd like a lab supply that's capable of driving a typical 100Wish power amp to the limits of it's capabilities, so something like 60V, 5A.

So ages ago, I lashed up the circuit shown. The idea is to use half a dozen N-channel lateral MOSFETs in parallel to do something like 60V, 6A. It never made it past the schematic stage.

Until now, when I need another couple of lab supplies to test my class-G amplifiers.

So I've spent the last couple of days doing layout, and come up with a reasonably simple 235mm x 65mm PCB, that has everything bar the transformer (actually 2, as I need a 2x12VAC low current supply to drive this), plus pots and panel meters.

Please see attached LTspice simulation, KiCad schematic, and PCB.

Alas I won't be ordering this PCB for a couple of weeks, as I've spent my play money on amplifier PCBs and I don't want to get into trouble.

New aluminum top plate for AR. Size 13 x 13 x 1/8". Drilled for AR T-bar and on/off switch. Cork damping on underside. New, still has protective plastic sheet on top, no marks or scratches. Purchased and built for customer who backed out of the deal. Motor and switch not included. Holes for spring bolts are not visable when platter is installed. Designed to use a side armboard like the Linn.

$30.00 plus shipping.

Hi
Here I am again with a new project.
This time I bought a radio from the 50s, the Ever Ready Super King.
These battery powered radios usef powered a 90V battery.
I will use either 10 9v batteries or some li-ion cells and a boost instead. Using a boost will allow the batteries to be recharged.
The filaments’ current is 25mA or 50mA at 1.5V.

I will try to re-use as many parts as possible.
As this is a single ended amp, the schematic should similar to the fender champ.
I will be posting as I move along.
Cheers
Pedro

hi all,

first 3 way crossover design here so im looking for guidance

the tweeter is 1x beyma cp21/f which is 8 ohms - 105dB 1/@1m
the midrange drivers are 2x B&C 6nsm51-8 in parallel for a 4 ohm load "100 dB, Applied RMS Voltage is set to 2.83 V for 8 ohms Nominal Impedance"
the mid bass drivers are 2x faital 10pr320-8 in parallel for a 4 ohm load 95dB 1w @1m

in practice these are some of my favorite drivers.. but I've always run them with active crossovers. I was thinking maybe I could try this and save on amp channels and DSP..

now im noticing the sensitivity is a little spread out, so maybe some L pads needed? that's fine if required..

for the HF I'd like to low pass it @20kHz @24dB / octave
mids x over to HF I'd like to hand off @4kHz with a 12dB / octave slope
Mid range to mid bass X I'd like to hand off @500Hz with a 12dB / octave slope
Low cut I'd like to roll off @45Hz with a 24dB / octave slope

and somehow, I'd like to gain match it all!

not saying I can't just go online and look up a 3 way calculator and how to make a bunch of L pads and filter circuits but im sure there are people here with much more experience doing this that I can ping off of

appreciate it " tips hat "

Apparently there is a gaping hole in my understanding of negative feedback! Normally when you apply voltage feedback, the output impedance will fall by the same factor as the gain reduction.

Yesterday I was testing a simple 6L6 PP amp, and measured the output impedance to be 170 ohms. Then I applied about 6dB feedback. THD fell by half as you would expect, but the output impedance fell to 16 ohms!

So I created a very simple circuit model to see if I was going mad, and sure enough I get basically the same result. What is happening here? Why is the output impedance changing by a factor of ten? I feel like I'm missing something very obvious!

Frequency response shown below, indicating 6dB of feedback. 6L6s are biased to 42mA cathode current.

Hi

I am working on this JCM 2000 DSL100 which a friend sent to me for checking. Upon opening the amp, I realise that a " JCM 2000 stable Bias Mod" has already been installed earlier. I plugged in a CD player and turned on the amp. At first the amp was working as normal, After a while, there was a slight buzzing and it startd to get louder, at the same time the music started to get softer. This contiued , the buzz getting louder while the music fading, After about an hour the buzz was much louder and the music could hardly be heard. The bias reading is stable and was not drifting. What could be the cause? Could it be due to the B+ voltage leaking into the preamp tubes or could it be a problem with the the Output Transformer. Please assist.

Thanks

I got small issue with my Denon pma 510 are.
After turning on you are able to change inputs for short time. Later on switch no response at all.
Remote control stopped working as well.
After replacing ir sensor, remote control works fine, and input selector switch as well.
But after hour or so, IR sensor diode blown again and everything stops working again.
Any advice? Please don't write about selector switch cleaning because it is not the case, switch it's brand new, old one was wobbly.

These are five variations on a simple SE. Small differences, but which one would you go for in the real world? It is mostly about 2H wrt 3H.

There have been a lot of nighttime large drone sightings recently in the NY and NJ areas. No one seems to know what these are, or if they do know they are not saying what it is.

One theory is that they are foreign based and coming from a ship just offshore.

The fact that no one in government can provide any sort of answer is particularly disturbing.

https://www.foxnews.com/video/6365887118112

Hi everyone,

I'm new to DIY and joined this community to meet with other diyers.

I'm an audiophile and am starting to get into speaker designing. Looking to start with small affordable builds and eventually build high quality speakers. I would love to build everything from scratch (even the drivers) and some day start my own company if it makes sense to do so.

Three x MC-616C (2-way L/C/R)
6.5" woofers, 1" tweeter 180 watts, 6 ohms, 89dB sensitivity
191/2"W x 7 3/4"H x 9"D
Weight: 24 lbs.
MSRP: $579 each

Also one RBH MCS-88 dual subwoofer as per picture. MSRP $500 each

Total MSRP over $2000

£250 for all four items. Can ship for extra. UK only. Sorry no can demo. Pick up from west yorkshire available

selling a Pair of RCF 850ND 2inch ; perfect state like new 450€ .
shipping to E.U only.

Hi everyone,

I’ve started putting together a small collection of vacuum tubes, but I’m realizing I could use some advice on how to better organize them. I’ve taken some pictures and uploaded them here: Vakuum Tubes

I’d appreciate any tips or ideas on how to sort and store them—whether by type, brand, function, or something else entirely. I’m also curious about any labeling systems or storage solutions you’ve found helpful.

Thanks in advance for your help!

Good morning to Everyone
Being interested in vintage loudspeakers I understand that TS parameters of a driver can vary with its age
I wonder why and what type of drivers can be more critical in this regard
Any suggestion and advice would be very welcome and precious
Thank you very much indeed

I need to pipe audio from uneBlade on a virtual machine on my server to a few separate Pi's with ShairPort. The reason is that the physical server/host is on another network segment, and a double-headed server is just as ill-tempered as a double headed troll.

The only reliable way to do that is to use one of the sound card outputs from the host (I have a bunch that feeds both these PI's and regular amps with cables, 14, if I'm not mistaken) and then the input of a USB sound card that is mapped to the virtual machine. I could use several USB sound cards, but that easily becomes a mess and creates problems on startup of the VM. So is there a sound card where I can use that has several line inputs, preferably RCA or 3.5 mm Jack, so I won't have to use any extra adapters? The TuneBlade works by capturing audio from any input on any sound card, but of course mic inputs easily gets distorted, even if they are set up in software as a line input. Here is a screenshot from TuneBlade:



It's the line in from the el cheapo USB sound card I'm using at the moment for one zone, but I want something better. Reasonably priced is up to $200, maybe 300 if there are many inputs.

Here is my measured results from 2 samples and manufacturers spec sheet

Disappointing but is there any real issues that I should be made aware of? Maybe just cross high enough with a small woofer?

Some time ago, I presented a complementary matcher based on a novel principle:
The same principle applies equally well to identical transistors, and it brings the same advantages: direct comparison between the junctions, with the TUT's themselves performing the comparison and a substantial amplification.

To demonstrate the operation, I have chosen a BC547B and a BC847B, which should be identical but aren't in reality (sim)



This time, no cheat is possible regarding the 0.1% tolerance of R1 and R2.
The calculation is the same as for the previous one:

Suppose that for a given collector current, the delta-Vbe is 1mV.
From the junction equation we can infer that the delta-Ic will be Ic*Exp(1mV/26mV)=1.039-1=3.9% for both transistors.
The difference is split between the two transistors, resulting in a 1.95% change. As the collector current is ~1mA, the variation will be ~20µA.
The voltage appearing across the two 3K3 resistors will thus be 6.6*0.02=132mV.
Thus, a theoretical magnification ratio of ~130; not bad for such a simple jig.

Here, the current is 1mA, but it can be changed to any value by scaling all the resistors values in the same proportion; self-heating remarks apply too.

Here are some pics:

I have a Fender 60 Watt Hot Rod DeVille with 2 12 Eminence Speakers and I recapped it not long ago and I changed one cap C1 to 22 uf to add some more tone I remember, Other than that one mod it is stock. 2002 Model Year. I had a nec and ge in it for about a year now and I was testing out some RCA 6L6 GC tubes in it today and individually They were 98% and 100% Emissions with 50 mV and 46.5 mV each. @ 489 plate, 487 grid and -057 bias. Cold Idle I set the bias to 63.5 and when they get hot it goes up to 102-104 mV at idle two tubes, it's Max idle @ 85 % . The tubes sound really good there Hot and I don't have any negative bias adjustment left. I turned the lights off and I was looking for red plates but I didn't find any but I noticed a little bit of blue haze in the tube near the getter and I tested them for shorts and grid leakage with my tube tester. The Amplifier has never sounded better than it does Now. I tried a pair of RCAs in it when I first got it and I didn't like the sound super bassey At 60 through 70 mV idle so I put what I had in it The NEC and GE instead At 63.5 mV idle no signal. It was okay but not really what I was looking for. I have noticed that blue haze before in 6L6 GC and other vintage 6L6 tubes. I was told Year's ago to just ignore it if they sound good. I played it for a few hours and it plays good. Am I worrying about nothing or should I be concerned ? I've heard some people say that 85% is fine with 6L6 GC Vintage tubes. I have 3 other pairs of The RCAs matching, I used to have a Fisher Ambassador that I converted to use 6L6 GC and One of the OTs went bad so I pulled the tubes out and I saved them. I forgot about them and I found them in a bag together the other day and they do match but I had another 5 of them also. I have two 97% @ 30/30 mV , two 97% @ 27/27 mV and two 100% @ 67/67 mV. They don't have any shorts or grid leakage. I'm A little bit afraid of using the two that Are even higher At 67 mV with The limited negative bias voltage and I don't really want to Use the other four because it's a Quad of working good RCA BP tubes. The Amplifier is actually quieter now At 104 idle than it was with the old tubes at 63.5 mV idle. I can run the settings down at 3 now and I have a good balanced room volume, they were up at 5 to 7 before on the clean channel. I don't want to burn up my 1200 dollar amplifier but I don't want to have a crappy sound either. I've got some really good vintage pre amp tubes in it. I know that I could play it safe with two of The other tubes but they probably are not going to sound near as good with 20 less mV idle. I've never really tried pushing the limits before with Guitar Amplifier tubes but it seems to me like the best sounding player's definitely do ! . I remember an old Sovtek MIG 100 lead I had that had 580 volts plate and EL 34 Vintage Mullards it was loud and clear and it would just about strip the paint off the wall. I want something like that but A little less loud. The 60 Watt DeVille seems just about right to me. I can still get good tone but At A lower volume. I play At home now and I just want to have a lot of extra power or headroom in Case I play out with A live drummer sometime. It really sucks when you can't play through the mix because you have a weakling Amplifier. And I tried the Hi power transistor stuff and up loud they didn't cut it for me. I had a custom built Crate Amplifier once that did but it broke down in short order. I'm done with those things. I guess that I'm just looking for opinions about The 6L6 GC RCA black plates and their limitations. The Old RCA tube Data is not really up to par with modern guitar amps with the Big voltage drops between plates and grids of 50 and 100 volts. I don't know exactly how to make sense of it for my application.

Where to connect power transformer screening:

-Direct to chassis ground with nothing more shared?
-Together with signal gnd to GLB (ground loop breaker) to chassis?
-Other?

Just acquired a single one of these - don't suppose anyone knows of another one that can make up the pair?

Hi guys ,
The source selector switch on my Rata amp is looking quite fragile and I did discover some small bits of plastic beneath it so I think it’s on its last legs .
I don’t really want to risk removing in order to identify it for obvious reasons so I’m hoping someone may recognise it ?

The amp is from the 1990’s .

Hi guys,


I am working on Sony v-fet gear for about 15 years as hobby. Mainly cleaning overhauling and readjusting them. I have worked on at least 50 Sony TA-4650 in that period and saved many of them from becoming just a big and lumpy paper weight.

And one issue is still hard to solve; popping speakers when turning off the amp. Renewing the relay and capacitors is standard procedure, since the old ones are unreliable. Checking all the transistors and when needed, changing the transistors and resistors aswell. Still sometimes it is impossible to not have this annoying pop in the speakers. Yes I do check all the parts in the speaker protection circuit.

And yes I am also aware of the later changes in the circuit advised by Sony.

Anyone an idea how to solve this annoying issue ?

I purchased this thinking it is a multi channel amp, but it is a multi room amp. I don't have all the cables and connectors to test the amp with so am selling as spares/repairs.
I purchased it as a fully working amp, and am pretty sure it is working fine, but am unable to prove it



£15 or ONO. Pick up from west yorkshire

Hello,

Looking for RAAL tweets, preferably 70-20XR

Let me know what you have

M

Several components for hifi/home audio in used condition are danger even outside of operation, because the integrated capacitors in the mains inlet C14 plugs are not disconnect from mains after switch off the component (and not to check and for replace).
Therefore the aging is more extend and it is not possible to check the condition like describe under
because the parts are potted and thus not accessible without destroy.

A friend of me observe such IEC C14 inlet versions with internal burning parts in his Linn Pre-amp KAIRN and Linn CD Player KARIK (unfortunately covered in a black shrink) exact according the description under this URL's:
https://www.vintage-radio.net/forum/showthread.php?t=88137
https://www.vintage-radio.net/forum/showthread.php?t=82160
https://www.vintage-radio.net/forum/showthread.php?t=69128
His apartment smelled extremely unpleasant despite ventilation for many days after this event.
Are the problems in this mentioned threads extremely rare ?

Because there is no access for replace the bad X2 capacitor - go to
Login to view embedded media only the possibility for whole replacing exist of course with the risk of the same issue after a certainly period of use (because all parts are always connected to the mains even after switching off the main switch).

Thank you for comments.

P.S.: In general I strongly recommend always to replace by a passive inlet (i. e. without integrated RFI parts) according the attached images No. 8-10
Additional an external RFI unit resp. mains filter according those under
https://www.audiomisc.co.uk/mains/filters1.html
or according the attached images No 11-16
but connected behind and not before the mains on/off switch.

This threads don't provide the wanted information:

Hi,

Not sure if this is the right place, but I'm looking to sell a pair of RAAL 64-10 OEM flat foil ribbon tweeters. I'm located in Phoenix, AZ, US. Willing to ship @ $300 inclusive of shipping. Will add pictures soon or DM me. Thank you.

Hi all. Searched and didn't see anything on this. Working on a DC power supply for tattoo work. Most I see are compact, and switching. VR, and some also offer CC and/or CV. I also saw some list frequency, but when I investigated, it's the needle frequency that you get with whatever V and I points the motor currently has. But that got me thinking...

What effects could be useful? And how to actually use tube(s) (not just decoration)?

Rectifying 18V@1.5a secondary? Nope. A triode as a pass element, maybe. What if...I use a CC/CV adjustable regulator to get my 20v B+, I could then burn some of the available current through a simple oscillator and load resistor. Say the reg output is 10v@1a. If I had an oscillator, variable from say 20-200hz, burning 400ma, then I'd have a DC voltage with variable frequency power ranging from 600ma-1A left available, for the gun coil in parallel with it.

So I looked for simple triode oscillators. I found this, but no formula. Most everything else was RF related, and certainly nothing below 500hz. If anyone could point to low frequency oscillator circuits, or just the basic math of it, it would be greatly appreciated. I saw that one of the oscillator types (Hartley?) use diodes even.

Thanks much all, this is a fun idea so far-
Loren

Bought a preamp board from Aliexpress along with transformer. When I hooked it up the transformer got very hot, so I disconnected it. Am I getting something wrong here or is the transformer defective? See pic of transformer. I hooked up the Green and Black wires as indicated to power .

With the success of my last design, a 3-way in the “classic” format (https://www.diyaudio.com/forums/multi-way/365119-soreta-3-classic-monacor-dayton-audio.html#post6493033), I started to think that I could replicate such a design with inexpensive but good performance drivers. The main problem with this statement is the availability of an inexpensive 8” driver with good bass performance and with low volume requirement. However my dreams came true with the availability of the PFC family of drivers from SB Acoustics, and specifically when SBA made them available also with a round frame.

I have yet to test the drivers but I have settled on the SB20PFCR30-8 for the bass. It should work reasonably well in my intended cab, even if some more volume would be preferred.
For the mid I was undecided for some time, and my first choice was the SB13PFCR25-4. But when drawing a sketch of the cab, I realized that in order to lay reasonably the drivers on the baffle and to make the mid enclosure not interfere with the bass I’d have needed to make a taller baffle than what I was thinking of. So I bought the 4” SB12PFCR25-4 instead, on the datasheet it appears to be sensitive just enough to mate well with the woofer.
The chosen tweeter is the SB26STCN-C000-4, I know that some other not expensive SBA tweeters have a small bit better performance, but for this application I prefer a small faceplate tweeter, and this forced my decision. And this tweeter should sustain well a planned 2.5 KHz crossover point.
In any case cost for the drivers for both speakers was around 170 Euro, and this fully qualify the SB(acoustics)INEX(pensive) name. Let we see what comes with the crossover.

Ralf

I'm a hard-core DIY builder. And by hard-core, I mean completely bonkers... 😀 😀 😀

For approx. the last 4yr I've been making build guides (here at diyaudio.com and elsewhere) for people interested in these projects. I've found that most interested parties can get one of these done with a bit of patience, guidance and a decent set of photos. So I've been doing that. It's a blast, and I've had the honor of taking to people (Email, phone, skype) all over the world about their projects and our hobby.



Most of these guides are Nelson Pass designs, but I will tell you that there is a reason his projects are so incredibly popular. Take a look -

Pass/Firstwatt F5 (My first big guide, and this is still the most popular project in DIY land) An illustrated guide to building an F5

The B1 preamp, this post got re-formatted and kinda screwed up, but still not bad. B1 preamp build thread

The incredible Pearl 2 phonostage - Building a Pearl 2

The F5Turbo amp (this one looks very clean, I'm quite happy with it) - F5Turbo Illustrated Build Guide

The legendary Aleph J amp, (what I've been listening to for quite some time) -- http://www.diyaudio.com/forums/pass-labs/241729-aleph-j-illustrated-build-guide.html

The Pass "Amp Camp Amp", this amplifier and guide is intended for the complete beginner, and so shows essentially everything -- ACA illustrated build guide

The Pass Burning Amp BA-3, this one has a video I really like in post #3 -- BA-3 Amplifier illustrated build guide

The front-end board from the BA-3 is a fantastic preamp, and currently in use in my system, here -- http://www.diyaudio.com/forums/pass-labs/258022-ba-3-preamp-build-guide.html#post3968063

The Pass F4, this is amongst my most favorite guides -- A guide to building the Pass F4 amplifier.

The wonderful Amp Camp Amp v1.0 ACA illustrated build guide

The F6 amplifier F6 Illustrated Build Guide

And a few non-Pass projects;

The O2 headphone amplifier -- Building the O2 Headphone Amp

Hagerman Bugle 2 phonostage - http://www.diyaudio.com/forums/analogue-source/237627-hagerman-bugle-2-a.html#post3605491


SL-1200 DC PSU -- SL-1200 DC Power Supply DIY

SL-1200 tonearm rewire -- Rewiring SL-1200 Tonearm

A guide to the universal chassis from the diyAudio store - http://www.diyaudio.com/forums/parts/245959-illustrated-guide-4u-deluxe-chassis.html#post3704810

And the universal PSU guide - diyAudio Power Supply Circuit Board v3 illustrated build guide


Gawd, that's a lot of things when listed like that. 🙂 I've never actually made a list as such. (And I haven't gotten any of my Valve project guides completed...)


My apologies, now that your eyes are bugged out from looking at all that, I suppose you would like to know a bit more about me... Here's everything you need to know about me in regards to DIY projects, a (literally) 5-min talk at Burning Amp Fest '13 -- https://www.youtube.com/watch?v=V5eOnuQJ3ww

Hi,

I am modeling with VituixCAD some 2.5 speaker. I do have couple of woofer measurements at hand, but the simulation shows that the low end of bassreflex box will be exactly the same if I put 2 woofers lets say in 10L box tuned to 60Hz or separate them into 2 x 5L chambers tuned to 60Hz. The only difference is 2 vents are mandatory then.

Somehow my guts feel that separate chambers will have better isolation of lower woofer diaphragm from mid freq inner bounces of upper woofer and lower overall acoustic crosstalk between them. But on the other side somehow have a feeling that bigger single box has some advantages... But cannot name them. 😀 Maybe none?

So, what would be your choice in every choice?
1. Two separate chambers or single?
2. In case of single chamber and single vent - the best position is probably in the same distance to each woofer? Does it matter?
3. In case of 2 chambers or single chamber with two vents - do they need to be tuned a little different not to have the same resonance?
4. In case of 2 vents - do they need to be in identical position to their relative woofer? If the distance of the vent exit from woofer cone is 5-10cm different between each woofer-vent pair - it can be measured, but can it be heard with ears?

Opinions and facts are welcome. Thank you!

Hello everyone. I've been interested in audio for quite a few years now and made a few DIY projects already. I found out about hornresp later learning about this forum. The hornresp app is extremely useful and full of features. I want to learn more about it and share my thoughts on different audio projects with other people here. I'm excited to become the part of the community.

1970 Pioneers from Japan. SA500 13watt. State of the art silicon transistors! Use it Everyday.

I'm Paul.
Living in Scotland.
As my hobby I'm repairing vintage audio, modern as well but not greatest fan of the smd 😀
I got some experience but like everyone sometimes I need some help as well.
All the best for everyone.

GRS12PT - sealed box on top with old Beta8CX/APT50/APT3 - series network 3mH/30uF from tapped pipe to 8CX woofer - 0.47mH on 8cx woof - 3.3uF.0.3mH on APT50 - some series attenuation w. some C bypass on CD.

Source = Flamma Drum/Loop mini pedal /Fosi TPA3255 mono amp.

Don't know what forum it fits ;^)


Login to view embedded media

This is the test result of 2SC2088 and 2SC2240
The distinct differences between these transistors happens near the low end switching point where 2SC2088 tends to by hyper sensitive.

HK870 Amplifier section may have blown outputs or blows fuse!
This is the case of a customer complaint ...
These days outputs are scarce and when available, they come at a premium price. Do I want to take a chance blowing or shorting my new transistors just by replacing them and see what happens?? No!
Since mid 1980's my instruction to my technicians have always been, make sure the amplifier driver stage all the way to its input stage (differential is any) is working good without installing output transistors. That understanding among the early days technicians and service engineers still holds true, just as anyone here agrees that the first order of business in any electronics repair is to make sure all essential power supplies are working properly.
In order to verify and troubleshoot the HK870 amplifier section, one needs to take some simple step. Here it is!
If you have any suggestion, I would like to hear it.

My sony TV is having an audio problem it shows a constant fast blinking green LED.
I have removed all the peripheral equipment and pulled the HDMI’s
Removed the smartcard
Powered down the TV for 3 minutes
Reapplied main power
Picture and flashing green led IMMEDIATELY return, normal video available
Sound adjust bar visible on screen in position Min
Increased the soundlevel using remote, audio is heard but as soon as remote sound button is released the volume automatically slows to MIN again
This is repeatable

Hold TV power OFF on remote for 5 seconds, TV turns off, RED LED is ON, GREEN LED is now off.
Turn TV back on using remote,
Reported problem appears again.

Any suggestions?
The problem started after watching Apple TV PHOTO’ via HDMI and having the Apple TV sound in MUTE

Hello all,
Returning member. Haven't posted here in probably 10 years. Looking forward to coming back. Many questions I have about audio as I continue to improve my system; many decades in the making now.
Some background information:
Have been an electronics hobbyist since I was 5 years old. Main interest is in amplifier designs and speaker building, and I have built many examples of both throughout the years.
Professionally, I have been working in the semiconductor industry for 27 years now, first as a test engineer, then as a validation engineer, and most recently as an analog designer.

Hi... I'm hoping I'll get some real advice on recapping 3 sets of speakers. I normally research topics pretty thoroughly... but this has been crazy!

Looking forward to your suggestions

Jonathan

Hi guy's ,

Has anyone did the mod ?

.

I know that it is not the best solution to use THT components in the case of TPA6120... 🤓
Any advice?

I have 2 Eminence Delta 10A - 10" drivers available. There were originally used in the 7Pi mid horn from Pi Speakers. I have moved to a different driver so these aren't needed. $120 for the pair. Free shipping to US lower 48 states only.