Hello everyone!

Thanks to all of the useful information from you guys, I was able to narrow down the problem on my 6N2/EL34 kit amp build to the output transformers. I had installed both of them backwards due to the lack of markings and the fact that the winding connections to the poles were covered. I should have probably tested them with my multimeter retrospectively, but an oscilloscope and sample tone helped me figure out and rectify the issue.

My amp now makes sound, however there is a constant hum present on one of the channels, even when there is no audio input connected. I swapped both of my output tubes and the hum was present on the other channel, so my tube might just be bad. I’ve ordered a matched set, but I am quite concerned about my heater voltages. The 6.3V tap from my power transformer reads 7.3 volts and I’m sure that’s the cause of all of the tube/hum issues.

Would it be a better idea to put a 1 ohm 10w resistor between the transformer and the filaments, or build a 5A DC regulated power supply (probably based on the LM317)? Also, my amplifier has the filaments directly connected to the 6.3V input. Would it be wise to add in a small value capacitor and a couple of 2W 300-600 ohm resistors between the filaments and ground?

Any help is much appreciated! Thanks!

I have a Denon DCD 2560 CD player. This is a high-end vintage unit that overall is in great working order and still sounds amazing. I had the belts replaced last year when the tray/drawer would not close completely. Now the unit has developed an intermittent issue where the drawer will not stay open. Sometimes when you press the Open/Close button, the tray slides out and then immediately (or, after a very brief delay) closes again. Pressing the open button again will usually result in it staying open, but sometimes you have to do this 3, 4...or more... times before it will remain open. Then other times, the door opens and stays open just fine.

I have opened the unit up, and there are 2 small switches (in the service manual for this unit they are referred to as "leaf switches") that appear to me to detect the open and closed positions of the drawer. I sprayed them both with electrical contact cleaner and - at first - I thought that had cleared up the issue. It seemed to for a time anyway, but eventually the problem came back. Maybe I just didn't get enough cleaner worked into them? They are positioned horizontally. I thought maybe if I could remove them, tilt them upright and let the cleaner get worked in better, that might do it? Or am I barking up the wrong tree even thinking its these switches? They are quite small and I would hate to risk breaking one, or the tabs that hold them in to place, in removing them - so I only want to try that if it's got a good likelihood of being the issue!

Any thoughts or suggestions? It cost me $125 to get the belts replaced last year, and so even though this is a high end unit, I am not sure I want to spend much more money fixing this new issue.

Thanks in advance for any ideas or suggestions. This is my first post here. Cheers.

First Crossover Design

Hey guys, I've designed a new crossover. Can you take a look at the impedance curve and tell me if the new crossover design is a viable one. It seems the impedance after 5k remains pretty much the same no matter whatever design I try with this tweeter.

I'm using Faital Pro 5Fe120 8ohm for the woofer and Dayton TD20F 4ohm for the tweeter.

I have considered using other tweeters but the only available tweeters here in India that fit into my budget are the Dayton Audio ND13FA, ND20FA, ND16FA, and the Peerless TL25AN. I've tried simulating with all these tweeters but I am yet to find a frequency response curve that I like. (I want to achieve somewhat of a flat response in between the 2k-5k region without any major bumps)

Also, a couple of other doubts.

1. The alignment of the tweeter and the woofer is not the same right? The point of origin for sound for the woofer is behind the tweeters. So do we take that into consideration when we design a crossover usually? I did and I've initialized the value of -56 into the Z-axis value for the woofer and then gone on to design the crossover. Is this wrong? Or should I ignore this?


2. I've had to inverse the polarity of the drivers. Now inversing the polarity of the tweeter gives me a different phase curve and inversing the woofer gives me another. Now my question is how what do we look for at those Phase graphs.

Due to the weight and size of my 65 Vibrolux, I decided to replace it with a Princeton 65 Solid State. It works well considering it's a disposable amplifier; however, the distortion channel is rather hissy, especially at higher gain levels, where the amp shines somewhat.

Looking at the schematic, two problem sources are evident. The first one is high resistance into the non-inverting input of U2A. The other problem is that U2 is a bipolar opamp. Perhaps a JFET input type may help, but the total of all those resistors will still be an issue. I know this from past experience.

To remedy the high resistance is not as simple as reducing resistance values and increasing capacitance values for the equivalent roll-off, because of the U1A circuitry. I have never seen anything like this before. It is not readily intuitive, at least for me.

Would anyone have an idea that doesn't require completely redesigning the input section? I would consider substantial modifications to the board, however. Here's a blowup of the input area:

Here's the entire schematic:
View attachment Princeton_65_Schematic.pdf

Any suggestions are appreciated.

Sold.




Thanks, Don

kicker

This amp plays audio for a few minutes and then stop.Is there a mute transistor in this amp?

RAIL and regulated voltage remains stable but protect led is lit when audio stops.

Hi,
I decided to make this amplifier from this page.
After assembling, I have problem with the sound.
DC Offset output is 14mV with +/- 37V.
The OpAmp is TL072 I replaced it many times.
Speaker is connected to before Zobel network.
The hfe of 2N3906 is 362 (max 300 in datasheet) and mpsa42/92 : 78/81 and mje15032/33 is 130/160.
Is it because of the hfe?

Thanks.🙂



The output sound
Picture of amp original quality

I'm using this amplifier: Buy Products Online from China Wholesalers at Aliexpress.com
To drive: 2x JBL602 4ohm car speakers.
It's for arcade machine sound effects, but I'll also use them for music.

My question is what voltage and amperage do I select for the power supply? 18V or 24V and then what current rating?

I get stuck with the calculations right away, with a 18V supply what is the max RMS power per channel that I could get into 4ohms?

Where I get stuck is: does 18V supply give me a max signal of -9V to +9V ??? (therefore 6.4V RMS, 1.6A , 10W per channel ?)

So, I found what Im building my speakers from, and very much looking forward to seeing the big brown truck deliver 😀

In the bit of work I have done in my life, I know wood expands and contracts during changes in temperature and humidity. Building anything with very dissimilar properties can cause surprises down the road....

That said, I could only find one source stating the dimensional stability of bamboo wood is better than most hardwoods. Obviously, the source was a bamboo manufacturer, so naturally what they sell has to be better lol..

But, they could be stating something everyone already knows, except me lol....

Im trying to decide what to build the bracing out of. Trying to figure out what to add as interior dampening panels.

If in fact the boo is better than most hardwoods, I would imagine Huber Advantec plywood would be the most parallel, and certainly the most moisture resistant material I have ever seen...

Wondering if anyone here has any history with it...

Exactly one year ago i finished complete refurbish (mylar and most electronics) on my Audiostatic ES 100's. They worked excellent until this week, when i returned home from a 2 week vacation. During my vacation i had the speakers unplugged from the wallpower so i guess they discharged completely. This was the first time they where disconnected from power for longer than a day.
Before reconnecting to power, i vacumed the panels. Something i have done once ore twice before.
After connecting them to i heard crackling noise in both speakers. Right speaker worse than left speaker. Crackling did not go away after few days of connection to mains and it is audible when i listen to music.
I have inspected the panels a few times very thouroughly by eye but i don't see anything wrong, like excessive dust, hair or holes in the mylar. There are no sparks visible in the dark. I did vacume again and also blow dry with hairdryer to get anything away that should not be there. Helas, without succes.

Could it be that i broke something by vacuming the panels or is it possible that some component (resistor or capacitor) did not survive a 2 week discharge? Anyone ever experience this?

Dear Forum,


Recently, I've discovered that one side's bass panels (both) started to sound distorted in a way. Both panels are involved at the same time, so it likely could be some kind of transformer problem, too in my opinin.

Does anybody here encountered any faults similar to this?
I've linked a video here (I had no luck attaching any audio or video files here at the forum)

I hope the sound fault comes through clearly as I cannot describe it more precisely than a 'distortion'


Thank you for your help in advance!

Got a JL Audio in for repair. The amp powers on. Power led and low ohm led are lit. Distortion, screeching and high pitch whine in the output. Sounds like the old dial up modems. Does it with no signal input also. I read there should be about 60 volts to ground on the speaker leads. I'm getting about 115 volts on the speaker leads. Checked the resistors in the output filter circuit. No broken leads and they check fine. Any ideas? Thanks!

I'm in love with the sound of this amp! Chassis build is next...

Hello all. I need help with this old preamp. It has a tube MC section, heavily regulated, using two 6DJ8 tubes, one for each channel. MC section is a separate entity, before the MM section, so two separate inputs. MC section started to motorboat. Signal goes thru, and the volume is fine. I checked the plate voltage and it's only 30v, coming from the PS, and after the regulators I get only about 10V on 6DJ8 plates. Knowing Jadis and their idiosyncratic designs I expected something strange but not this. I checked all electrolytes around, and they all check fine, with ESRs in .26 ohm range, and uF within 5%. There is a pot on each plate, to regulate the voltage, I assume. Perhaps they have to be tweaked. Since there is no service manual available, I'm shooting in the dark. Any help is appreciated. Thank you.

I'd like to center my voice coil with a low-freq test tone without desoldering the leads from the woofer. I removed the driver with leads still attached (see photo) and connected leads directly to the driver but it does not move the driver. I tried frequencies form 5-500 Hz. Unless the voice coil is broken, I can't understand why this would not work? Why wouldn't this work?

How is this done?

Speaker mfrs tells to the customer that ”this” speaker is good for a room size of 10-15 m2 and amp power of 20-50 watts, and ”that” speaker is good for rooms of 20-30 m2 and 100-300 watts, how do they come up with these figures?

In my recent setup i have come to the conclusion that i need a lot less then i ever had thought, this in entirely because of the room used and how the speakers must be positioned

Hi There.

Im looking for a pair if those tubes


Thanks
Marcin

Hi.

I,m interested in building Mark K,s er18dxt. It looks like a perfect candidate for my next build.

However, the tweeter placement is off set. Now, I understand why this is but my "mental" disorder just can't deal with the visual.. . 🙄

How bad impact would it be to center the tweeter on the baffle?

Thanx and best regards.
JZ

i have one in my shop. all 5 amps have 50v to each fuse.so supply is good.i disconnected the input and power supply to all the amps and still stays in standby. the relays on the control board both click when i power the amp on.theres no dc offset on any of the 5 outputs.any help with where to look would be great. thanks

Hi there,

I have got a receiver from 1970, a Saba Studio IIa, it features all germanium transistors, so it got a line transformer in front of the output PNP-transistor. and its a nice sounding device.
but i want to modify it more to my taste of playback. and i would really appreciate your thoughts about it.

so far i just replaced or added some elkos at the voltage-stage. and replaced the series C521, because it was faulty.

i would like to deactivate the tone-control. in the ciruit-diagramm, i added a green line for connection and a red for a line-cut, as i would do it right now.

the Receiver got a "Linear"-Switch on the front, if it is not pressed, you get this bathtub-response-curve. - don´t need this either, but its not interfering if not chosen, i guess.

and about the feedback-loop: do i get this right? it just affects transistor AC161 and AC117 trough R542 (680Ohms)? if so, in which range would it be save to vary the value of R542?

and finally: anything you would do to improve this amp?

i have the whole service-manual btw.

thank you,
Daniel

Hi Guys
Would like to hear from you experts on why's of this speaker. Though I don't know much about speakers, I do think that there's really some clever engineering & thoughts that went into this design by the old gurus.

1. Speaker cone : It's paper but coated with if memory serves me correct a glue made from corn starch, what is special is the surface feels rough to touch. I believe the glue was mixed with some granular medium. Question : Why so, is it to add strength like cement & sand or was other factors involved. I must say the cone is really stiff & I guess heavy too hence the huge magnet used I think.

2. Cloth surround: Think it is dope cotton or silk but for me never seen it use this way, mostly are pleated with heavy doping & stiff

3. Rubber Ring : This is also interesting, there's a groove on the basket where this ring is push fitted in. This is not a gasket as the expose part is half round like the surround. Question: Is it to help damped the basket & does the convex surface helps with diffraction etc ?

4. U shape thingy: This is located in between the 4 basket support, think this is a damper of sorts.

These are just my own speculations, would like to from from you experts what your thoughts are.

Thanks

I am repairing a Threshold 4000. The left channel had some blown transistors. I replaced all of them with MJ15024/MJ15025. Furthermore, I found 2x transistors (1x MPSA42 and 1x2N4250) and 2x resistors blown on the driver pcb (CFE 379).
Before powering up with variac I'd like your support on the bias setting. The emitter resistors are 1R. What voltage should I be measuring on them? I have found contradicting directions on the web from threshold owners/diyers and just wanted to know if there is any official bias procedure.
Any support will be really useful to finish this project and finally enjoy the amp. Regards!!

Masks 1 pieces 2.5 $
1 packs of 50 pieces 125 $
Limit purchase per person up to 2 packs of 100 pieces

Due to regional restrictions, only free shipping to the US
Due to strict restrictions in other regions, it is difficult to send
But you can contact me and i will try my best

My email: email deleted



Medical single-use face mask respiratory protection surgical mask 3 layers
Condition: new and unopened, durable until June 2022

3-layer glass fiber-free filter medium
Integrated nose piece
Latex free elastic bands
Type II according to EN 14683
1 packs of 50 pieces
color green

I'm building a 10" 3-way speaker, and I'm pretty green with electronics, so I need help with several questions. I'm using Morel drivers, and while the tweeter & midrange are 8 ohms, the woofer is 6.4 ohms. Is this a problem? Could it damage the amp? Could hooking up just the woofer to test it when the amp says "8-16 Ohms" damage the amp or speaker? Would I need any kind of special crossover, or can I just buy a standard off-the-shelf model?Many thanks for any help y'all can provide.

So I was getting ready to pursue my build(s), and contemplated how/where to place the toroid.

But then, if you look up the topic, you'll find plenty dreadful warnings a la "don't put a screw through the middle of the toroid or the thing will blow up" etc. which of course frightened me.

Here's what I found:

You have to make sure the bolt/screw doesn't touch both sides (or top/bottom) of the chassis, and you're fine.

Or you go creative and use something non-metallic.

This was designed and built mainly in weekends. It took a while, but this is the best solid-state amp that I ever listened. Very transparent and very clean due to very low levels of TIM distortion. One of the reasons for very low TIM distortion is the isolation of the input voltage gain stage hence very steady offset even with large droops of the power supply voltages. Another reason is the local feedback for the input stage built with the excellent OPA445. The noise of the amp is below the threshold sensitivity level of my Agilent 34461A benchtop meter. The S/N ratio is better than 110dB. I had to increase the gain of the amp in order to measure the noise. I also dimensioned this amp for 25 and 100 W / 8 ohm, and the sound is very accurate with any of the variants.

G

This wouldn’t be complete without this module.

G

I went dumpster diving last week and found a pair of huge LED lighting heatsinks that I managed to fabricate into a decent amplifier assembly.

Now, what am I going to do with them ?

I've got an Aleph 4 which is brilliant. I have heard that the Aleph X and Aleph J are worth listening to.

This case should be quite good for a good Class A amplifier.

Hi,

I'm trying to repair this amplifier with the following problem:
Display shows nothing, just light up.
With display in place there are no error codes.
With display removed CH1 Thermal LED blinks 1x & CH2 Thermal LED blinks 2x.
According to the service manual (p82) the problem is 'LCD Communications Fail'.
Is the display faulty or is it the IC U706? (Microcontroller) ?
Problem here is to get these parts!

Best regards.

I just received a nytech cta 252 to repair.
it is one of the very first model.
he suffered quite a bit of damage but nothing irreversible.
it is one of this generation with really old transistors (bcx32 / 36, bc309c, bc238c)
I wish to restore it so as not to distort its original identity and above all not to unbalance it.
so I ask those who really know this circuit to tell me what equivalences I can use (except for power transistors) and what are the critical points to respect in this circuit, because there are a lot of diagrams on the internet but nothing clear and I don't want to upgrade it obelisk or ion way.
idem, if transistors are "critical" in termes of gain or spec, I would like to know.
thank you

Hi


I need some help with this amp. I plugged in the power supply, plugged in a signal and turned the amp ON, There is power going in to the amp, but no sound. I did not hear the relay "click". I then plugged the amp thru a Variac, turned on the power switch, and starting from 240V, I slowly brought the voltage down in steps. At about 160V, the relay clicked on and there was sound as normal. At 160V AC, when I turn the amp on and off, the relay kicks in within 2 secs without any problem. If I increase the voltage back to 240V with the amp turn ON, the relay does not click off, but when I turn the amp off, plug in direct to 240V, the relay does not kick in. I have checked all the transistors and diodes on the power amp board, and they test OK. Can the problem be due to a leaking cap or transistor. Pls assist.


Thanks

Hello.I want to add aclipping indicator to my amplifier.It uses +-45.5V rails.

Any suggestions?

Hi I was going to build a simple bass guitar preamp with eq/tone shaping circuit.

QUESTION 1:
If I can only pick 4 bands, what would be the best in your opinion?
bass mid1 mid2 and treble would be the setup.

QUESTION 2:
Also I have a design I was working on with a single mid range cut, but parametric control. Because my control is a simple transistor gyrator circuit, there is a limited range. The constraints of my simple circuit are such that:
the high mid frequency range is twice that of the low mid frequency range.
i.e. I was thinking the parametric control would go from 250hz to 500hz.
or it could go from 200hz to 400hz, or from 500hz to 1000hz etc. If you could pick one range, what would range do you think would be best?

Thanks everyone for your thoughts

Hello Guys.


I am looking for some technical help with a Sony CDP101
I am restoring this elderly machine, and have an intermittant issue with the Spindle Motor, it doesn't always start correctly.


When you insert a disc the motor turns very slowly and has trouble getting the disc up to speed, therefore no TOC read, and disc ejection.


Other times the motor spins up correctly, the machine reads the TOC, at this point when you press PLAY, one of two things happen.


1 The disc will spin up quickly, and the machine will play the disc
2 The disc is lethargic to spin up as in the problem earlier reading the TOC, the machine eventually times out and ejects the disc


It seems as though there is a "Kick Start" signal missing when the disc is lethargic to start.

I have the manual, but am struggling to determine the sequence of events during disc spin up. I have checked all other aspects and been through the alignment process, I do notice an issue during the CVLS alignment process, RV202 seems to have no effect.


Any guidance would be much appreciated,
Thanks

Pete

Hello, iam looking for the part number of this smd part. Ist not from an amp, but maybe somebody could help anyway. It's from an antminer z9mini hashboard

Hello everybody

I need your help in the design of the amplifier
In pdf page 17
is the schematic of the amplifier

http://www.linearsystems.com/lsdata/files/Denis Vilfort Burning Amp Slides 2019.pdf


My questions :
- Is it possible to build it with a lower supply voltage (2 * 28V)?
- with 2SK1058 / 2SJ162 transistors Renaissance?
- with transistors of the BC550 / BC560 series in LTP (or their SMD equivalents)

I tried to do simulations in LTSpice but I'm not an engineer so I don't have the proper knowledge (only by trial / error method ;-)

Thank you

For the first time, we feature an isolated sound card for the Raspberry Pi and other embedded systems.

It would probably be of interest to many people on this forum.

Come checkout our new project, the Isolated sound card here :
Audio Injector isolated DAC & ADC (Raspberry Pi compatible) by Flatmax Studios — Kickstarter

Hope you join the campaign. If you like the project, please share the above link with your groups/communities.

Matt

I've visited this site many times and am impressed with the expertise and willingness to share. I've learned a bit about acoustics but am quite clueless on the electronics. Will be posting a question about design of "listening" room in the appropriate forum.

Thanks

Hey friends. First post here and excited to take the plunge into the rabbit hole. Planning to build an amp/preamp/integrated to drive my new Klipsch Forte III speakers that are in the mail. Heard them in the local shop while getting my TT fixed and was hooked!

What amp kit do I want? Lots of recommendations for tubes with horn speakers, most often suggestion being Bob Latino ST70. Have not looked into ANY solid state kits. Having a volume remote and tone controls would be cool but not a deal breaker.

Only have two sources, a Denon DP300 TT (built in preamp) and streaming sources (currently Apply Music via AirPlay, maybe Tidal, so either an Apply Airport Express or Bluesound Node). Musical interest runs the gamut from rock of all decades, soul, reggae, funk, country but also jazz and occasional classical. I’m a bass player so bass control/response is important to me.

Just brought a dynatron radiogram may have to ask for help and support from those with the knowledge

Thanks in advance of any help and support

Dear Victor,

I wanted to write to let you know how pleased I am with my new Sparkler DAC (S504 Unison). I love the sound! It really makes my jazz and classical music collection come alive. Everything has a much fuller, richer sound versus the previous DAC I had been using. Some other reviewers have called it a “musical” sound and I agree – everything sounds much more lively with this DAC. I attended a live classical music concert yesterday and enjoyed the immediacy of the sound. This was what I had been missing with my previous DAC.

Besides the sound, the Sparkler S504 Unison DAC just looks cool. The handmade gold colored Japanese paper is quite distinctive. This DAC is very much a unique, handmade object, so rare in this age of mass production. I could have spent a lot more money on a so-called “prestige” brand DAC, but honestly this is much better – how many people have a Sparkler DAC?

I also ordered a full set of Sparkler interconnects, plus speaker wiring and a USB to SPDIF converter. All seem very well made and reasonably priced, and work great. Despite being custom made, the Sparkler products are priced well below other supposedly affordable brands.

I love that Mr. Tsukahara is basically running a one man shop, doing all the design and production by hand. He should be commended for his efforts.

And thank you for supporting him!

Best regards,

Jaylat

Hey all I'm looking for schematics for my S/500 or the values for setting up DC offset and Bias, if anyone has or can help out that would be awesome.

Thanks much

Nyle

I've just spent two weeks in the Sin Bin and on return have found my subscriptions folder empty. Is this an additional form of punishment or a system problem?

I have enough spare parts to make a PSU for a Salas 6V6 preamp. The idea is to run it from a 24V DC power supply.

I have several of these:
VI-J1B-EY | VI-J00 Series DC-DC Converters | Vicor
and a few others, enough to make a 330VDC B+ from a 24V PSU. The idea is to put the converters in series to get the necessary voltage. I might put this on the final B+ output: 21st Century Maida Regulator: A modern B+ voltage regulator – Neurochrome

I also have this, that I can trim to 6.3 for the heater.
VI-J1T-CY | VI-J00 Series DC-DC Converters | Vicor

I plan to use this ripple attenuator, which I also have, on the output of 6.3V converter.
Ripple Attenuator Module - RAM | Vicor Corporation

Besides the fact that this is all unnecessarily complicated, I'd like to try it. Are there any reasons not to? How about at amp startup? As I understand it, this might be a difficult scenario for the PSU.

Can I put an NTC on the output of the 24VDC power supply, and before the converters?
https://www.alliedelec.com/m/d/5537bfe04244704ae50832ab5bfb2832.pdf

HI .DEFY 7 HAS BLOWN RESISTORS. I ALSO HAVE SOME SMOKED AREAS . ANYONE HAVE SCHEMATIC ? PLEASE CONTACT ME CARLWADE3@GMAIL.COM:

Per the title. Shipping to TX. Thanks!

I ask you to read this carefully, a thread has already been closed for this serious issue, please do not mess it up.

And if you don't have anything important to say, skip it.

Thank you for the good of humanity!

Coronavirus: Why You Must Act Now - Tomas Pueyo - Medium

Ok, Here we will continue from where we left off from previous thread - Open source speaker project?.
First poll result was for a 3 way classic speaker (no horn), the budget is 500-1000$ for drivers only (excluding the crossover parts and cabinet).

EDIT 9-20-18 :
Tower XL discussions and development will be continued here :
Open Source "Tower XL"

Hello,

I'm designing new cabinets and I thought it would be nice to keep the baffle surface around the tweeter and midrange as small as possible to give the ultimate openness, airyness (?) and soundstage.
I came up with this, the tweeter and midramge are in a very small sort of bookshelf on top of the bass cabinet. This is very small. Though, the bass cabinet is like a wall, this will only cause worse reflections. What do you think. Line that wall of the bass cabinet with sound dampening and will it be very good or will it be better of with just a normal large baffle?

VHC stands for "Very high Current". 45wpc pure Class A all the way up to max. Famous for driving extremely difficult 1 ohm loads like Apogees.

I could use a pair of the ones with turquoise frames, the discounted version of Scan Speak 10f.

I am gutting an HK550vxi for the amp. I have successfully removed tone, volume,balance,rec,tuner,phono RIAA and RCAs and rewired it to a single RCA input. Sounds great, now I am building a new enclosure, changing the speaker terminals and power switch. The new enclosure is mostly made of wood, the only metal in it is the 1" amp riser and the back panel. The amp board currently has a ground to the metal chassis, can I connect this to the amp riser and back panel and call it good? I could also make a small chassis to contain the transfo, ac power input and inputs outputs but that would be harder and it takes away from the fast and dirty hack aspect....When this one is done I have a Denon AVR3300 with a 5 channels at 105W/8ohms that I need to gut

Thanks

For Sale:

Little Bear Tube Phono RIAA Preamp. Three 12AX7 Tubes, and the Tube rectifier has been modded to SS (can be easily reversed...)

How's $100 + Ship?

Panasonic SA-XR55 9 Channel amp - one channel not working...

I always loved how these Panny pure Digital amps sounded...this one was on basement HT duty for a while until I decided I needed a HT Receiver that was able to switch HDMI (this does not have HDMI)..still a fantastic sounding amp when connected to digital source...

Anyway, hows $75 + ship or pick up West Sub of Chicago?

Hi Guys
Im having a problem while loading settings.
This error apeard.
CSRA64150-error — ImgBB
I tried to reset the module like on this link but nothing worked.
How to Restore AudioB Plus Module Default Settings
Any Idea why?

Can any of you audiophiles help me with this question ? can a Tube Preamp enhance an A/B Amp . I've read conflicting info on this subject on the web with authors saying high end boutique amps use this set up. But after watching a Bob Carver video he explains how a tube Amp works with it accepting return power to the tube by reflection of the driver and an A/B cancels this effect. So I'm confused now thinking maybe a tube preamp would be a waist of money.🙁http://https://www.youtube.com/watch?v=LQ9USqpclWc
The amp boards are 4- Yuan-Jing 3 x TDA7293 Parallel 250W Mono Power Amp Board .
Any help would be greatly appreciated....

After making full range floor standers and a pair of subs I want my next project to be a 2 or 3 way. I’m trying to get to a higher degree of realism at higher SPLs than 6” full range can do. I only need low end above 80hz (or maybe as high as 100) so I’d like to maintain a modest efficiency (say, above 90db/W) without a huge box. Listening distance is typically 8-10ft when on the couch, the room is 16x32’ with cathedral ceilings.

I’ve been looking a at a couple of Troel’s Designs, specifically the Quattro MKII and the SBA 16 MTM. At my most adventurous his Faital 3 way seems doable but frankly is a bit bigger than I’d like right now. I love the look of big speakers but I’m short on tools and workshop space to manage big cuts and parts.

So I’ve been poking around the web for weeks and I’m hoping a little input from the forum will help me find any other options that fit and ultimately pick something to work on soon.

Thanks

Hi all.

Next up:
a pair of boxed (but not identical glass) RCA 6l6GC. I think these are NOS, but not certain. These are also sought-after black plate (see pics). Both test strong on a calibrated I-177 tester (4600 and 5300 micro mhos). $175 USD for the pair.

Next are 6 X cx-301 globe (01a equivalent). My Gm measurements are (1000, 1100, 1200, 1200, 1300 and 1400). All are strong and were purchased from a reputable dealer and never used. I always saved them and used ST envelopes, but now don't have the 01a preamp anymore. $150 USD for the set of 6.

I'm shipping from NZ.

If you have a lot of posts on diyaudio, I'm happy to guarantee them. If you don't, I won't guarantee.

If you have helped me out on any of my posts in the past, send me a PM and I'll hook you up with a sweet deal.

You pay shipping and PayPal fees.

Next up will be a heap of Russian valves including 4p1l.

Please see my other auctions for a bunch of 45 triodes.

Thanks for the community guys.

Hi

New to DIY and wanting to make a Awesome Top Level sounding 2 way BS pair

Was reading on great reviews on Purifi Drivers but not much work done out yet since its new. Its expensive and was looking at a good option to Purifi will the
Wavecor WF182BD10 woofer/ SEAS H1215-08/ SEAS H1224-08 be able to compete with the Purifi if someone can throw some light on. I do not wish to use a 3 way or add a subwoofer. Desire is to have the best 2 way Bookshelf room size is 14x20ft

Would like to go Active with miniDSP and Hypex or ICE class D amps.

Do not want to go the passive route.

regards
Rajeev S

How to connect dual inductor (in single shielded package) in Class D audio Amplifier for SE (stereo) & BTL (Mono) configuration ? Both inductor have opposite starting and finishing winding point (Ex. 7444211415100 from Wurth Elektronik)

Hello guys!

Lately, I've been working intensively on Class D amplifiers.

Now, I have developed the following circuit and wanted to know what you think about it.
For example, I am not sure if I designed the negative feedback correctly.

Unfortunately, I cannot simulate the entire amplifier because I have not found any Spice models for the LM5104 and Si8610BB. I am using LTSpice, Multisim and Tina TI.

Important: R21, R32 and R34 are 0R jumpers and are for test purposes only.
At the end, R21 and R34 remain empty.

Thank you for your answers!

Best regards

Simi
si1505do@gmail.com
DIY Electronic Projects

hi everybody

im trying to find some pure copper fork/spade connectors. i thought i'd found the perfect one's but, on reading the description i discovered their gold plated.

does any body know where i could find something close to these in pure copper ??
8pcs Pure Copper Spade Plug Speaker Cable Wire Connector HiFi | eBay

gaz

Jupiter beeswax-paper-oil-caps-pair-1-uf-600vdc
55$ and shipping

WANT TO BUY a front panel in silver / gray for AMC CVT-3040. Thank´s!

I have redone a pair of those MK3 to original with tube rectifier,etc.

I just got a power transformer issue, primary is short. Secondaries are all ok.
It does not smell burning, i did open it could not reach inside the primary section as mostly have to destruct it completely.
Anyway, P782 dates maybe from 40years++
I was in a Paoli design modded MK 3 amps I bought used.
I highly suspect that, because of this Paoli design that used a SS rectifier and a 1000uF capacitance, it did fatigue the power transformer all right .
This Paoli mod was supposed to be great, but I now don't belive it, and if a product or item is design for a typical service, please , let it be the same.
Just to advise community here.
Will replace both P782 soon, well it happens..........

So I'm wanting to try bi-amping, but of course there are already passive crossovers in my speakers, and I understand I'll have to remove/replace, or at least modify these before I can make the most of bi-amping with an active (or software, at first) crossover.

The speakers have 'bi-wiring' binding posts, with the +high and +low, -high and -low paralleled by plates. I've traced the two crossovers out, in ignorant noob style as you can see 🙂 I'm hoping somebody can help me identify the topology so I can determine where I need to cut a trace, add jumpers etc to disable the filters an active cross will provide.

I'm hoping there'll be a way of just skipping the first filter of each unit, drilling a hole and moving those input wires.

I'm not able (easily) to measure the inductance of those big coils, but if it's required knowledge, then I'll find a way 😛 I can tell you however that the mid/bass crosses at 150Hz, the mid/high starts at 1k, and crosses to the tweeter at 6k.

Cheers for your time, to anyone reading the thread ;P

You know, because of the (well-founded) fear of contracting COVID-19, planes around the world are flying without passengers. Needlessly spending millions of liters of fuel and polluting the atmosphere, etc. etc.
This, the news says, is because if they don't, airlines will lose assigned routes.
This is a difficult thing to accept. Is a temporary suspension of said regulation so complicated to implement?

It seems that there is not enough place in airports to park so many planes that are constantly in flight, in an established routine, that cannot be interrupted, and nobody could have foreseen the advance of COVID-19!
It seems logical, if we also think that the available parking spaces are already occupied by many 737 Max out of service.


Is that so?


Experience

Anyone have a schematic manual? D309 is shorted, IC305 is blown to bits, D615 in the regulator circuit is also blown to bits, Reg608 is shorted.

thanks.

Probably too late to ask seeing as I've spent some time today building this!

I have soldered up the cap bank for a 51Vdc supply for a tpa3255. Used 14 of 2200uF caps and for packaging purposes I have 2 rows of caps.

These are all aligned ground inwards, so the two inner copper wires are ground. One outer wire will be in from the bridge rectifier and the other outer will be the smoothed supply.

Have I made a potential ground loop with the physical looping of the wire around the caps.?

Question for all you F7 clone builders, can 2SK1058/2SJ162 be used for outputs?
Are these lateral Mosfets?

I have a set of Polk S20 speakers that were dropped and now sound like crap. I'm in the process of replacing the drivers in them.
The specs from Polk's website state that these are 8 ohm speakers, yet when I measure the voice coil of the woofer with my meter I get a reading of 3.56 ohms, which is typical of a 4 ohm woofer.

Why is this?? I understand that an 8 ohm speaker will read less than 8 ohms DC resistance but it shouldn't be this low. So now I am wondering if I need 4 ohm drivers. Confusion!!

Hello to all
in the "MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)" tread I inserted a post on the MDDXH135 prototype. It has an omnidirectional MDDFL front loading for high frequencies, very simple to make, and an MDDBL rear loading for low frequencies that requires more work. I will continue to insert the new posts in the "MDD Multi Delays Diffraction (Multi TL, omnidirectional, single drive, ...)" tread.

Acoustic loading systems can also be used in 2- and 3-way systems.

The MDDFL front loading makes omnidirectional the emission at medium and high frequencies for any electrodynamic speaker.

MDDBL rear loading can be applied to the woofer. It has 12 transmission lines with 12 resonant frequencies distributed over an octave, effectively making its behavior neutral in the frequency domain. See neutral cabinet page.

For those who want more information on the MDD technology that led me to develop these acoustic loads, I recommend the acoustic page.

Right now I don't have the material or the skills to make quality Multi-Way systems. I am available to give more information about my prototypes for experiments in Multi-Way systems.

Thanks for your attention
Claudio


MDD3FE25 an MDD project with the 3FE25 driver
https://www.diyaudio.com/forums/pla...nidirectional-single-drive-8.html#post6170069
other documentation is published at MDD3FE25.

Hello

Anbody compared the sanken 2sc3855 to the 2sc5200 into power amps ?

I have few of those sanken 2sc3855 and 2sa1491 (old stock)

Thank you

Gaetan

Greetings,
I have an M8 and the line inputs are not working with record engaged. Do you have any suggestions?

Hello.
Can someone help, like a tutorial, how to plot and find trans-conductance for a valve (ECC81) for a given Ia(plate current).

In the datasheet the trans-conductance change with Ia and Va. In the datasheet it is 5.5mA/V for 10mA at 250V, but how can I find how much for 1mA at 250V ?

Thank you.

For sale here is a vintage UTC CG-101 swinging choke. This is rated for 150ma. and has a dcr of 110 ohm. 5-25hy operating current. This would be great for a choke input power supply for a EL84 PP amp or something similar.

$75 plus shipping. Paypal friends and family please. Shipping is from Vienna, Austria.

Thanks!

I have these resistors and I dont have a use for them. Hate to see them just laying around.

Make offer or trade?

Caddock MK132V
300R 1% pair
5.49k 0.1% 4qty
2.315k 0.1% 4qty
4.346k 0.1% 4at

Also.. I have 4 Caddock MM224N @ 1MEG 1%