Has anyone come across the Piccolo or Mandolin projects from Jeff Bagby? We were very interested, I would like to know more about them.

Just joined. Not sure if this Is the way to go? PL 50 has been in cabinet for 40 + years. Cleaned it up new belt, lubed and oiled. Switched on. Turntable starts.
Switch all the way on. SWITCH IMMEDIATELY RETURNS TO OFF.. Help..

Tannoy uses a system of screw-in pins on the front of their current prestige speakers to change the 'treble energy', which I believe is just changing the taps on an autotransformer. I would like to do something similar on a pair of DIY speakers but cannot figure out what these pins are called and if they are something that can be purchased or if they are bespoke for Tannoy. Any ideas? I'm thinking they may provide a better sounding result than a rotary switch.

hi- ive looking out for a pair of these- impedance is quoted 4-8 ohms- does anyone out there know the actual impedance- dc resistance will do- many thanks

I'm trying to find some chip to start a design with. I haven't designed anything in D-class and I'd like to see how horrible radio transmitter I get.

I'm planning to make universal amplifier or active speaker amplifier and in the front there will be DSP to make cross-over, magic and coffee 😉

I have short list of requirements:
- Clipping indicator. I don't have spare ADC or CPU cycles for to process this.
- 25+W/ch power. I'd like more if I end up driving subwoofer
- Single side power. I'd like to get away with cheap Chinese led power supply

What I've found is so far TPAxxxx can give me 2/3 of requirements but no clipping control. If I'm going to use some LED PSU, and it just doesn't can't handle the load, it is essential to get the info to turn down the volume.

So do you have any good candidates to take a look?

I have a pair of DIY, mono-block, push-pull, KT-88 amps. They’ve been running properly for over a year; but, I do tend to tweak and experiment a little more than is probably necessary. I’ve been looking for around 50 watts. I read that at 450 b+, 65 mA would be max bias; so I’ve been working my way up to about 57 mA and getting pretty close at 19.5 vrms.

Last time I put one of amps back into the system, I noticed a low hum through the speaker. A couple of days later, the hum turned into a screech. On the bench I’m able to set all dc voltages with no problem. At idle, hooked up to a preamp, an 8 ohm summy load, a signal generator, and a scope, the amp sits quietly until I start to apply preamp power. Then the signal becomes audible and increases in volume with increases in preamp power. There is no speaker in the system; so, I'm assuming the noise is coming from the OPT.

I could supply the schematic, but before getting into that, I wonder if anyone could just steer me in the right direction and let me know where you would start to troubleshoot this situation.

Thanks in advance.

I have a 12" driver and building a ported box of approximately 4.3 cubic feet and tuning to 22Hz. This could be fed as much as 600 watts of clean power from a Crown pro amp XLS 1502. Using WINISD to model. In that program I am concerned about port velocity numbers it is throwing out. Some say don't go beyond 17m/s while others say up to 30 or so will be just fine. I have modeled using two 3" ports and a single 4" port. Not too much difference between the two, so given the choice I would use a single 4". But with either of those choices the port velocity is as follows.

At 300 watts of signal the port velocities for two 3" or a single 4"
at 20Hz 35-40m/s
at 30Hz 16-18m/s

Having two 4" ports solves the problem, but I am thinking two 4" ports might be overkill. Seems like a lot for a single 12" driver, although the Xmax on the driver is 26mm so pretty substantial. I just don't want chuffing during a low rumble in a movie. I will flare the ends of the ports using a 3/4 roundover router bit.

Will a single 4" be fine?
Thoughts?

Hello,

I have a problem with my Technics SU-V2A This is about the phono preamplifier. Technics uses an IC (SVITA7322P) as phono preamplifier in this amp. One of these ICs is defective in my unit.. The signal comes in at the functional channel at pin 2 into the IC and out at pin 7. At the defective IC only a DC voltage of about 0.7V can be measured at the output.

I would like to replace the IC, and maybe even improve the quality. I found a TA7322P on the internet, which seems to be the same, but I'm afraid to get a fake IC here.

Do you think it would make sense to remove the entire phono input circuitry in its original form and design and install a separate module, for example based on the RIAA preamp here (ESP Google Search Does anybody know an alternative source for this chip where I can be sure not to get a fake IC?

The service manual can be found here (Technics SU-V2A Stereo Integrated DC Amplifier Manual | HiFi Engine), the phono circuitry can be found on Page 13 and 14. I've attached these pages to the post.





Thanks in advance

Lukas

He put it out as a "holiday" present on the blog:
Walt's Blog 2014 | Walt Jung's 2014 Blog and Info Archive

I stocked jfets for RF and general use during last period activity. Now coming back to my first love, may some parts find also applications in audio ?

• PN4416
• 2N5486
• BF256
• 2N3823
• BF245
• U410
• 2N4093
• 2N5460G
• 2N3966
• J110G
• 2N5462G

Does Anyone have a source for these clips? Sometimes amplifiers are missing them or they break when removing them. Whatever the case may be. Alot of amplifiers use them. I have been searching high and low, amplifier manufacturers in china asking them to sell me 1000-10000 pieces. i just can not find the correct source for them. Does anyone know of a replacement?
😱

Hello,
I'm building a bass reflex enclosure for the Seas L19RNX1

H1878-08 L19RNX1

I have simulated it on winISD and regardless of what I do with the enclosure parameters, xmax is hit @ 40W. Id like it to be a solid 90W, which is were the tweeter has had enough. The L19 is rated for 200W RMS, so it can definitely take the heat. Is there a way to increase power handling for a driver in a br enclosure? I'm worried 40 watts won't be enough volume for a 86 dB sensitivity driver...

Going beyond Fourth-order...

I see many active crossovers or DSP now use filter beyond 4th order popularly. Is it a good idea to go beyond 4th order filter on passive crossover network? Does anyone has any experience on this?

Ok guys I have a JBL GTQ 400 with i believe a power supply issue. If i supply 12v from my power supply once the remote turn on is applied it drops voltage to 6v to 7v. Any ideas? The mosfet's seem not be shorted.

Hello friend. I have AMP TARAMPS HD10000 and I have berned smd element.. I do not understand what it is for and what it is responsible for?
On the Internet I did not find anywhere about this ...
CASE - SOT-23-5
On the:
TARAMPS 8k - 6QKE
TARAMPS 10k - 6QKE
TARAMPS 8k - 6QKE
TARAMPS 15k(2016) - 6KSB
TARAMPS 15k(2017) - 6RFM

I've never seen anything like this in amplifiers before.

I got one of these amps in and they had the twisted wires switched around on 1 side of the amp . Which blew all of the outputs .

The twisted wires are disconnected from the rectifier side amp still draws excessive current .

Here is what I get on the power supply fets

Scope set to 5us .5 volts/div
The trace was centered before taking pics

If these look good any ideas where to start checking ?

Hi all,

I was browsing for 3" (75mm) midrange domes with an idea for a new project.

However I found that two of the best are no longer available! The ATC and the TangBand 🙁

How possible is it to use a good compression driver as a midrange dome? I'm sure I've heard of people doing this.

I've got absolutely no experience with compression drivers. Would one remove the back cup to access the dome side, or what?

The drivers from BMS and Radian look like very well engineered items.

Yeah I know about the Volt driver and the ScanSpeak / Vifa D75MX

I've had these drivers in a closet for a long time and thought I should do something with them. But I can't find any data for them except what's printed on the back. 80W, 4 Ohm and 75-22000 Hz. I would appreciate if I could get some more data.

I'm new here and far from an audio expert. Trying to set up a karaoke system using the following:


1. Smart TV with hdmi input


2. Laptop - hdmi out to TV and audio out (headphone) to Mixer. The laptop runs the online karaoke service I belong to.


3. Mixer to Powered Speakers. The powered speakers have as input: Digital Coaxial and Digital Optical. This may be my biggest sticking point. I'm not even sure if I need a mixer but in my research, most seem to have. In research, it seems most use an XLR cable. But my speakers do not have XLR input - only Digital Coaxial and Digital Optical. I can't seem to find or know how to set up a mixer to powered speakers with Digital Coaxial or Digital Optical. Nor do I want to spend $300 on a mixer - hoping to get by with $100 or less. Based on this information can anyone give me a clue how to set up


4. Wireless Mic with a base as a receiver. Even though I'm not 100% sure basically I think I would just plug the mic base into the mixer but please elaborate if correct or not and maybe confirm what cables and inputs are involved.


In the above list, I have Smart TV, Laptop, and Powered Speakers. I'm in the market for Wireless Mic, Mixer, and whatever cables I need.

transfo is overheat why

Hi guys I'm busy on a taramps 12k bass I did the power supply of the amp it's powering up 100% but the issue is the amp has 4 to 5 volts on speaker terminals when powered up the owner says it's been like this since he had it I tried adjusting the bias pot but doesn't do anything or just a very fine adj what could be the problem

Hi all,

I have a WAF Najda board and never used it! I want to do so soon.

Where can I get the Najda Under Control (NUC) software to configure it over USB, please?

Can someone share it with me?

Really sorry to see they shut shop. It's still a superb bit of kit today.

Thanks.

Im trying to wire some bass shakers on one single line for the amp and I have 3 of them. Two are the same earthquake mqb1 and the last is a buttkicker lfe.
The mqb1's are showing me a 5.3ohm when I test them and the buttkicker is 3.8.
I found an online calculator about doing 2 in parallel and 1 series that keeps the ohm level at 6.45 with the majority of the power going to the buttkicker wish is what I want.
Is this diagram correct?

Has anybody else ran 3 speakers together like this before?
Im assuming also that once I come off the rca to my dsp that I have to tune that whole channel as one? I cant split off that signal and control them individually?

Hi,
I'm experiencing a very irritating constant hum on my newly arrived Sansui SR-222 MK V turntable. Seems like a cable issue but I can't figure out where. The TT is grounded to the amplifier (Audiolab 8000A).
I even opened it and in its simplicity nothing seems wrong or visible oxidation.
The cartridge is new and the cables are plastic shielded.
The hum is present even if the turnable is not connected to the power but much lower in volume. Simply switching to PHONO and there it is.
Anyone has ANY idea where the hum comes from?
Sending some pics.
IMG-20200725-145531 — ImgBB
IMG-20200725-145547 — ImgBB
IMG-20200725-201600 — ImgBB
IMG-20200726-110647 — ImgBB
IMG-20200726-110705 — ImgBB
https://ibb.co/GHKfDcN

There is the DIYinHK multichannel interface that is supposed to have recording capability. This is really affordable and probably a very high quality option.
2 concerns are the lack of ESD protection in the DIYinHk interfaces some people have mentioned, I have had 2 diyinhk i2s interfaces and they both stopped working eventually, a cheap amanero interface has outlived both... it's unacceptable.
The other concern is compatibility in software, will it be detected as an input device , will it actually send an input. Diyinhk documentation is nonexistent, there are no first hand reports on using this interface for recording either.

The other option is miniDSP, but i dont think its a very high quality option looking at the boards, its far more than just an i2s recorder at that price so it's not a surprise.

Even disregarding price, are there no other options at DIYinHK level of quality?

SOLD
Selling the two (2) boards and controller chip (as a set) if you are interested in installing an electronic volume/remote in your gear. New & unused. Price today is $57 plus the wait time for delivery from Germany.
See the following link for the discussion of same:
MUSES 72320 electronic volume
SOLD - Will ship to you USPS Priority Mail in the USA for $50. $45 plus actual shipping cost in the ROW. SOLD

Hi! Some years ago I asked my self how to change the diode laser to the laser pickups. I bought this cd, very similar to P-D70 and P-D90 and equal to P-DX500, I saw and it seemed very interesting. When arrive it hardly could read any cd.
One focus coil was unsticked from the lens, I stick them with glue and it went ok.
I tried to change the laser diode and to adjust watching the RF signal. Here I realized that to changing the diode is not as easy as appears. Then I bought some genuine and fake LT022mc diodes, and without power meter it was a mess. Besides, some adjusts are very critics. All tryings only was getting to worse the situation. When I broke a corner in the flat cable I decided to stop, until getting more knowledge.

As I said the clue was in the manual of the Pioneer P-D70.

Now I decided that this moment arrived, and finally the cd is playing
again.

The process was similar to the other laser pickups. To conect with a flat cable, put it front a mirror, force the laser power, oscilloscopes, power supply and low frequency generator, as usual.

One problem was that I had to build a "excentric screwdriver" for to adjust the pickup. With the fingers or other tools was impossible.

Another thing I saw is that the laser I placed was dead. It was dued to power laser adjust in the laser pickup, if you force it you can break the laser easyly. For to adjust is very important the lase power meter. For to adjust with oscilloscope I use the lowest power as possible.

Then I placed the laser. I adjusted the laser power to 260uW.
The cd player was totally manipulated and out of parameters. At first the cd was totally dead. It cost me a lot to get anything at first.

For to adjust Tracking Balance was necesary to trick the cd lowing the Tracking Gain. Some adjust was easy and clear, and other impossible to perform due it's necesary a external device.

I did not adjust "grating" because I saw while I was adjusting that waves a-b-c-d get disajusted. I saw the grid with a lens and I placed the grating by way of were placed ortogonally the track in the disc, said in other words, the grid were placed 90º to the cd track angle. I don't get risk to adjust and waste all the work.

Another critical parameter was the spindle motor height. And the most difficult was the "spindle motor horizontal adjustment in tangential direction". This causes that some disc reads at the begining well and not a the end and viceversa.

And that's all.

In the process were some more problems, but to tell the entire story could be a nighmare.

In spite all problems, I tried to repair it at all costs because I saw it was a very interesting device, and very educational. I learned a lot with it an their manual.

In the video appears a grey aluminium Pioneer PD-6010 with a PWY004, that is very similar to the VWY-063 from the P-DX700. It looks to have a LT022MC, but "unfortunately" these laser unit is perfect.

Pics

Pioneer P-DX700 VWY061 VWY063 PWY003 - Google Photos

Video

Pioneer P-DX700 VWY061 VWY063 PWY003 laser pickup with new LT022mc laser - YouTube

A friend of mine has a Sansui stereo tube amplifier with 6R-A8 outputs? This amplifier is great sounding, but we can't seem to locate output tubes for it. Anyone here seen these? Know where they can be purchased?

Hi,

Does anyone know much about PT Too power supplies? Does anyone know how they work?

When searching the internet and asking on other forums, no-one seems able to help as if these are a complete mystery yet from looking at the circuit, it seems to be a very simple amplifier driven by a (complex looking) sinusoidal waveform generator..

I am wanting to revive my dead one which failed when I accidentally turned it on without the motor connected. Surely this would just mean rebuilding the TDA2004 amplifier circuit as I can't imagine any damage would go back further than this. Could this be correct? The opinion I get from people is that when a PT Too PSU is dead, it is dead forever but I just don't believe it..

Incidentally, one of the three PSUs I've amassed has all the chip identities intact so I can show all the CMOS chips that are in the circuit should anyone be interested - perhaps someone wants to clone it? Just let me know and I'll get snapping with my camera.

I'd be greatful for any help.

Nat

Today is the day!
Switzerland is celebrating!
For those curious about how the story goes (according to Schiller), here‘s an entertaining roundup... enjoy

Hi friends! I was cleaning and discovered that i have 145 volts DC regulated power supply and bunch of 6J1 tubes. I think i can find 6 or 12 volts supply, so i am thinking about building something. Buffer or preamp. Sure i searched, but i would like simple verified schematics someone tested and is happy with it. Not that crappy 'fever 6j1' which circulates around.

I am not able to find the Thiele-Small parameters about the follow website:
Classic - Vintage 30 - Celestion - Guitar, Bass & Pro Audio Speakers
Who can help?

Sold. Thanks for your consideration.

1. Scanspeak Illuminator 12MU/4731T-00 4.5" Midrange Pair
Condition: Like New
Price: [SOLD]


2. Scanspeak Illuminator 18WU/4747T-00, 7" Aluminum Cone Woofer 4 ohm Pair
Condition: Like New
Price: [SOLD]


3. ScanSpeak Illuminator D3004/6040-10 Beryllium Dome Tweeter Pair
Condition: Like New
Price: [SOLD]


4. Dayton Audio Omnimic V2
Condition: Good working condition
Price: [SOLD]


Shipping is included to continental US. Buyer can pay via PayPal via either friends and family or via products and services. It makes no difference to me, but I request that you pay the service fee for products and services transactions. I will let you know the total via PM.


Photos:

Hi,

There is another transistor(IC) , I am having problem finding replacement. I understand that this 2SA798 is an IC made up of 2 transistors. Can this component be modified.

Please assist

Thanks

Carlosraj

For reference

One of my amps has an fx loop with a weak buffer and loses a lot of high end with a pretty short cable run - even worse, when I try to use line level effects (with a 10k input impedance) the signal drop is huge. I'm going to put together an op amp based buffer and thought I'd fancy it up with 1 or 2 relay switchable loops. I want to keep the box close to the amp with a pedal for actuating the relays

I sketched up a pseudo schematic/block diagram for feedback before I start to do a little board layout.

• My pedal supply has a 12v @ 200mA output that I would like to use. It actually has two that can be paralleled but I want to start with a budget of 200mA.
• The analog circuit would have an op amp at the input as the primary buffer. I'd use a rail-to-rail part for headroom. I think I'd put another buffer at the send side of each loop as well. Basic stuff, non-inverting voltage follower AC coupled with a 1/2Vcc rail for bias.
• The loops would be switching TS jacks half normalled together (plugging into the send doesn't break the path, plugging into the return does) - 1 loop would be hard wired, the second and maybe third would be relay switchable.
• The relays would be 12v units with modest coil currents. I found some miniature relays that use less than 50mA each
• The relay switching would be accomplished with NUD3112 parts. They are cheap little drivers with built in protection. I'd pull their gates up to 5vDC with a resistor and zener and short the gate to ground to change relay states

Potential parts:

https://www.ti.com/lit/ds/symlink/opa1641.pdf?ts=1594314003691&ref_url=https%253A%252F%252Fwww.ti.com%252Fdocument-viewer%252FOPA1641%252Fdatasheet
https://www.mouser.com/ProductDetail/863-SZNUD3112LT1G
https://www.mouser.com/datasheet/2/307/en-g6a-1148492.pdf

As you know, Wavebourn Audio Research Laboratories (Austin, TX) is known by high quality affordable audiophile power amplifiers and preamplifiers, and we commit to our customers as long as they need our products and support our business, but due to current problems we add to our line of production powerful, but safe electronic disinfection devices.

The lamp consumes 38W to cover the disinfection area up to 600 sq ft during 60 minutes, but protects you from being exposed to direct UV rays pausing in presence of a human being or a pet.

A radar shuts the UV-C lamp off as soon as somebody moves. It protects skin and eyes from exposition.

Ultraviolet light has been used for disinfection for over 40 years. Now researchers from Boston University and Signify (formerly Phillips) have confirmed its effectiveness against the latest problem.

In particular, Anthony Griffiths, Ph. D., Associate Professor of Microbiology at the NEIDL Laboratory of Boston University, revealed that 5mJ / cm2 UV-C dose deactivates 99% of the problem in 6 seconds. According to him, he and his team found that a dose of 22mJ / cm2 UV-C radiation reduced the amount of active problem by 99.9999% in 25 seconds.

This lamp emits 2 wavelenths, 185 and 254 nM, generating additionally ionized oxygen that kills bacteria and fungi in places where rays do not reach.

Upon request, bulbs that do not generate ozone can be installed. They have additions in the bulb that make kind of LPF that stops 185 nM that the oxygen absorbs.

We received first trial party of UV-C disinfection lamps. They are gorgeous! We are looking for dealers now in USA and Canada, while continuing working on their improvements. PM if interested!

$147/sample. 4,000 / month volumes will be available.

PM me if interested to participate, or to buy one sample.

Hi Everybody! I am new here. I just purchased a very clean used T101 Tuner. I am looking for a users manual as I don't know how to use all the features. Can anybody help with a copy? Also, the AM tunes in the wrong increments. I had the same problem on a shortwave portable but realized there was an external switch to change it to the correct spacing. Is there something on this radio that changes the spacing for the USA?
Thanks,
Bob

This is the size im working with and I understand its pretty shallow. Should it give me any concerns?
39" long x 30" wide x 9".

This is fitting under and ottoman I built so it has to stay that shallow if I want to build it.
Those dimensions come to about 4.0 cuft

Im not sure if I should do a big round port or do a slotted design. Ive been using this speakerboxlite software to get me around the idea of what id like. Any ideas or changes?

powered by one open line on my Behringer 6000d so should be plenty of power to get it done.

Good day,

Can anyone help me with an issue with an Aguilar DB751 bass amp?

When turned on the status led blinks for the normal 45 seconds and goes steady
But the operate led is off. There is no input or output. Unit worked fine when powered up before transport for a gig and when powered up for gig this occurred. Anyone came across this issue with this amp? All voltages good and relays are enabled.

Hello!

Somebody can point me on where i can buy coupling transformer of rf t1500. Thank you!

What I think I know so far: I = V/R. And also P = VI

Looking at the TDA7377 spec sheet, I see Vop = 18, Vs = 28, Vs(peak) = 50.

http://www.e-ele.net/DataSheet/TDA7377.pdf

But I will be using Vs = 10 to get 10W (2 x 10W into 4ohm speakers).

Using I = V/R, I get: 10 volts / 4 ohm = 2.5Amps
Using I = P/V, I get: 20W/10V = 2 Amps (20W = 10W x 2 speakers)

How best to calculate it using the chip's spec sheet as a reference?

Obviously I'm not going to be playing sine waves through it - is there a rule of thumb I should take into account?

Hello.I am having this amplifier.any suggestions on optimizing part values for good stability and performance?

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

EDCOR - XSE Series Output Transformers

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

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

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

Any ideas? I appreciate input on this.

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

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

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

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

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

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

Is this a good idea?

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

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

Philharmonic BMR Bookshelf Speaker Review

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

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




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

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

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

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

Datasheet

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

Hi,


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


Drop: Passions lead here (formerly Massdrop)



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


Thank you

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

Here's an unusual "DIY" project:


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

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

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

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

A few design choices:

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

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

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

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

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

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

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

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

Hi Friends,

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



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


Regards,
Sadik

Some say yes others no!

What is your take?

Please state the reason for your answer.

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

Please jump into the fray. I'm listening.

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

Sincerely
Kris

For reference.

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

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

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

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

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

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

Hi all,

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

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

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

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

or whole donor coax:H0489 P17REX/XF

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

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


Thanks!
Daniel

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

For reference:

For reference.

For reference.

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

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

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

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

All found here - PrimaLuna

Hope that helps! 🙂

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

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

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

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

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

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

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

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

Any pointers would be appreciated.

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

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

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

Hopefully someone can help. Thank you in advance!

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



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