Discrete Class-A headphone buffer for BA3-FE, no feedback
- By stachel
- Headphone Systems
- 30 Replies
Attachments
very "textbook" single ended Class A amplifier i designed
- By No ideas
- Solid State
- 70 Replies
i want to use up my irfp140(i used the irfp240 becuse i couldnt find the model for the 140) so i designed this amplifier, the weirdest thing here is the second supply for the voltage gain stage, its here to compensate the common emitter gain stage losses and make the voltage swing a little bit bigger without adding more parts, also compared to my last se amplifier i used mosfets which are supprisingly not that awfull.
Hammond 273BX is smoking after putting it in the two diode center tap arrangement
- By sander19
- Tubes / Valves
- 53 Replies
Hi,
So I am following up from a recent stereo tube amp design that was not working and right now I am working on the power supply. Please look at the picture below as well as the schematic. When I add power to the transformer it hums louder increasingly and beings smoking which is a sign something is not connected right. Please advise, thanks!
So I am following up from a recent stereo tube amp design that was not working and right now I am working on the power supply. Please look at the picture below as well as the schematic. When I add power to the transformer it hums louder increasingly and beings smoking which is a sign something is not connected right. Please advise, thanks!
New DISPRE preamp, successor to previous popular version
- By PMA
- Analog Line Level
- 643 Replies
Attachments
5k SE Transformer Tests: Monolith, Edcor, Antek, and Tamradio
- By pjanda1
- Tubes / Valves
- 27 Replies
Attachments
TPA3255 Bluetooth Car Amplifier, Battery operated Boombox.
- By PowerBoomer
- Class D
- 6 Replies
Attachments
dual bridge rectifiers - one for each channel or one each for pos/neg
- By robthomp
- Power Supplies
- 20 Replies
Hi,
When building a power supply for an audio amp with a transformer that has a center tap, or better yet dual secondaries, and using two bridge rectifiers, I get that you can use one bridge for the positive and one for the negative rail, and then share the split rail supply with both channels, as in this standard Pass DIYaudio design, from the Aleph J build guide:
:
Alternatively, Rod Elliot suggests this "dual mono" design where you have a center tap transformer and two bridge rectifiers and you use one bridge rectifier for each channel, as in this link:
rod elliot power supply
I'm wondering what the pros and cons are of each of these approaches.
I get why you would want to separate the channels, to avoid 'cross talk', but what's the advantage of separating the pos and neg rails?
When building a power supply for an audio amp with a transformer that has a center tap, or better yet dual secondaries, and using two bridge rectifiers, I get that you can use one bridge for the positive and one for the negative rail, and then share the split rail supply with both channels, as in this standard Pass DIYaudio design, from the Aleph J build guide:
:Alternatively, Rod Elliot suggests this "dual mono" design where you have a center tap transformer and two bridge rectifiers and you use one bridge rectifier for each channel, as in this link:
rod elliot power supply
I'm wondering what the pros and cons are of each of these approaches.
I get why you would want to separate the channels, to avoid 'cross talk', but what's the advantage of separating the pos and neg rails?
Interest in balanced line receiver boards
- By alexcp
- Group Buys
- 25 Replies
UPDATE: This GB is now closed. The boards were manufactured and are being shipped to the participants.
Earlier this year, I created a thread about a balanced line receiver board:
Since there have been some questions on the availability of these boards. I am starting this group buy to see if there is enough interest to warrant a manufacturing run.
What it is
(1) Your name here on diyAudio -- (2) number of board, pieces -- (3) Country to ship the board(s) to.
Try to preserve formatting.
Running List for Subscription :
alexcp -- 2 -- US
This group buy will close on Saturday, September 30. Be sure to sign up before then.
Earlier this year, I created a thread about a balanced line receiver board:
Since there have been some questions on the availability of these boards. I am starting this group buy to see if there is enough interest to warrant a manufacturing run.
What it is
- One 68x28mm (approx. 2.7x1.1in) all-through-hole board implements one channel of high performance balanced line receiver.
- The use case for this board and its theory of operation are discussed at some length in the main thread.
- Low distortion. The board allows using modern opamps (e.g. the LM4562) and has much better distortion performance, both measurably and audibly, compared to most integrated balanced line receivers (e.g. THAT1200 series).
- DC blocking. The board includes an active DC blocking filter, making any coupling capacitors unnecessary.
- Choice of balanced or ground sensing output. The output can be configured as balanced or as remote ground sensing.
- The balanced output option is useful if your downstream device has a balanced input. (Note that balanced means equal hot and cold output impedances. Only the hot wire is actively driven, so you won't be able to drive two amplifiers BTL fashion).
- The ground sensing option is useful for downstream amplifiers with single ended inputs. Configured for ground sensing, this board corrects for the difference between its own ground and that of the downstream amplifier, making sure that the latter sees the correct signal at its input. The details are discussed in the beginning of the above mentioned thread.
- Choice of gain. The default gain is 0dB (unity), however, the gain is set by discrete resistors, and any reasonable gain can be chosen.
- Good CMRR even at higher frequencies thanks to an advanced PCB layout. Typical CMRR is better than 50dB with 1% resistors and better than 70dB with 0.1% resistors.
- Will depend on the level of interest, starting with $5 for one board (one board = one channel, two are needed for stereo) plus shipping. Should the total number of boards exceed 50, the price will go down.
- Shipping is flat $5 for the continental U.S. (USPS Ground Advantage) and $15 elsewhere (USPS First Class International Package). Should you want to buy something else from me, I of course can combine shipping.
- The schematic and the board outline are published in the main thread.
- The board uses compact axial metal film resistors, such as Vishay CMF50/RN50 or SFR16S, Yageo MFR12, KOA Speer MFS, etc.
- Other components are very ordinary and allow broad substitution. Since the board is through-hole, one can socket the opamps and try opamp rolling.
- Full BOM and assembly instructions will be provided.
(1) Your name here on diyAudio -- (2) number of board, pieces -- (3) Country to ship the board(s) to.
Try to preserve formatting.
Running List for Subscription :
alexcp -- 2 -- US
This group buy will close on Saturday, September 30. Be sure to sign up before then.
Musical Fidelity A308CR Power Amplifier Recap Suggestions
- Solid State
- 124 Replies
I have been using Musical Fidelity A308CR power amplifier and preamp that I have been using with Totem Hawk speakers for quite some time now. The build date is stamped in 2003, they are both officially 20 years old to date! Everything works great and looks good internally but considering the age, I'd like to give them a refresh and replace the 20 year old capacitors and upgrade a few internal bits as well. I also have modified a Musical fidelity x10v3 tube buffer with an upgrade kit by guy named "Rockgrotto" who supplies modifications for these units (basic soldering, and removal of the old tubes + caps) but that is the extent of my abilities with basic knowledge. So I am open to any suggestions you guys have and what you would change internally in these amplifiers.
Btw, feel free to criticize as well if you don't like the amplifier design - please explain why though! I am aware that Musical Fidelity tends to use fairly basic/average components in their designs (Jamicon caps) and the wiring seems fairly substandard, amongst others. I however look at that as a positive - these amps sound pretty darn good as is (and were the top of the range at the time from Musical Fidelity) so updating/replacing the weak stuff with caps from the likes of Nichicon and adding thicker internal wiring could only make it something special (or at least that's my logic!)
Below are pictures of the a308cr power amplifier for now, as that is what I want to tackle first. So far I am looking at replacing the 8 Jamicon 10000uf 80v caps with Nichicon 10000uf 100v caps (LKG2A103MKZ) and all remaining smaller caps with similar ratings by Nichicon. There are also 14 Metallized Polypropylene Film Capacitors that I would like to update and I'm open to suggestions on that (Wima? Siemens MKV?). Kimber TCX for the main board to binding posts, while using Kimber TCSS for the signal path wiring. I may also consider changing out all the diodes for something better quality as well, but again, I'm open to what you guys think. It has also come to my attention that the amp should be biased properly, but I don't have the equipment to do this - is this necessary? Thank you all in advance!
Btw, feel free to criticize as well if you don't like the amplifier design - please explain why though! I am aware that Musical Fidelity tends to use fairly basic/average components in their designs (Jamicon caps) and the wiring seems fairly substandard, amongst others. I however look at that as a positive - these amps sound pretty darn good as is (and were the top of the range at the time from Musical Fidelity) so updating/replacing the weak stuff with caps from the likes of Nichicon and adding thicker internal wiring could only make it something special (or at least that's my logic!)
Below are pictures of the a308cr power amplifier for now, as that is what I want to tackle first. So far I am looking at replacing the 8 Jamicon 10000uf 80v caps with Nichicon 10000uf 100v caps (LKG2A103MKZ) and all remaining smaller caps with similar ratings by Nichicon. There are also 14 Metallized Polypropylene Film Capacitors that I would like to update and I'm open to suggestions on that (Wima? Siemens MKV?). Kimber TCX for the main board to binding posts, while using Kimber TCSS for the signal path wiring. I may also consider changing out all the diodes for something better quality as well, but again, I'm open to what you guys think. It has also come to my attention that the amp should be biased properly, but I don't have the equipment to do this - is this necessary? Thank you all in advance!
Satori 7.5" mid-woofer coaxial tweeter for Voigt Pipe Focal Flax EVO
- By Unseen
- Full Range
- 3 Replies
Is this Satori suitable for a VP and how ideal?
Also the flax evo
| 7.5" Coaxial Driver Combo Tweeter and Mid-woofer |
| AudioXpress.com Test Bench |
| Data is correct to stock at time of printing, however SBA are constantly improving their stock and data may change without notice. For the latest datasheets, please see www.sbacoustics.com |
| Black Cone |
| 60W |
| 7.2mm |
| 0.31 |
| 0.5kg/s |
| 1.13mm/N |
| 43Hz |
| 90dB |
| each |
| Mid-Woofer |
| 37.1L |
| 6.54 |
| 0.33 |
| 0.12mH |
| 0.12mH |
| 8 ohm |
| 1.1T |
| 152cm² |
| 165mmØ |
| 39mmØ |
| 12.1g |
| 0.13kg |
| 116mm |
| 187mmØ |
| 6.5Ω |
| 8Ω Re 6.5Ω |
| Satori |
| Single |
| Satori |
| SAT16-GRL |
| 1 |
| 60Wrms |
| 7.5' |
| 8.05Tm |
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Bl
[/th]Also the flax evo
Need help with oscillating amplifier (Denon POA)
- By kbanks
- Solid State
- 206 Replies
Hello all!
I would really appreciate any help i could get here since i've been working on this amplfie for way to long and i'm still having problems. I have invested in a new scope to se if i can get any leads. Since i'm new to using scopes and in general an amature i have realy no idea what to make of these measuements down below.
The problem i'm having is that the amplfier seems to oscillate and cause my voltage rails to drop and my DBT is flashing slowly and low. Powering on amp with CN6 connected i'm able to get out of protection for about 5 seconds and then relay kicks in and protection light goes back on. Most parts on amplifer board are replaced with new ones and all elektrolytic capasitors are replace with new quality ones. The measurments down below are with and without CN6 connected. The scope is set to AC Couple because something is telling me im getting AC-ripple or oscillation from AC?
Main amp board:
PSU
Pic 1 probes at red and black from PSU (pink position) : CN6 disconnected . FFT 10Khz (I'm having problems setting trigger point becuase waveform is jumping all over the place, up and down)
Pic 2: Same as above but FFT 25Mhz (high freq)
Pic 3 probes at red and black from PSU (pink position) : CN6 connected. FFT 10Khz (waveform more steady!)
Pic 4: Same as above but FFT 25Mhz (high freq) (waveform more steady!)
Pic 5: probes at CN13 position from CN6 disconnected . FFT 10Khz
Pic 6: probes at CN13 position from CN6 disconnected . FFT 25Mhz (high freq)
Pic 7: probes at CN13 position from CN6 connected. FFT 10Khz
Pic 8: probes at CN13 position from CN6 connected. FFT 10Khz
Pic 9: probes at CN13 position from CN6 connected. FFT 25Mhz (high freq) (2.2V ac coming true?)
Pic 9: Probes at test point 1 & 2: CN6 Connected. FFT 10Khz
Pic 9: Probes at test point 1 & 2: FFT 25Mhz (high freq)
What can be the cause of this. Maby Brdige rectifier are failing at load or anythin else to concider?
I would really appreciate any help i could get here since i've been working on this amplfie for way to long and i'm still having problems. I have invested in a new scope to se if i can get any leads. Since i'm new to using scopes and in general an amature i have realy no idea what to make of these measuements down below.
The problem i'm having is that the amplfier seems to oscillate and cause my voltage rails to drop and my DBT is flashing slowly and low. Powering on amp with CN6 connected i'm able to get out of protection for about 5 seconds and then relay kicks in and protection light goes back on. Most parts on amplifer board are replaced with new ones and all elektrolytic capasitors are replace with new quality ones. The measurments down below are with and without CN6 connected. The scope is set to AC Couple because something is telling me im getting AC-ripple or oscillation from AC?
Main amp board:
PSU
Pic 1 probes at red and black from PSU (pink position) : CN6 disconnected . FFT 10Khz (I'm having problems setting trigger point becuase waveform is jumping all over the place, up and down)
Pic 2: Same as above but FFT 25Mhz (high freq)
Pic 3 probes at red and black from PSU (pink position) : CN6 connected. FFT 10Khz (waveform more steady!)
Pic 4: Same as above but FFT 25Mhz (high freq) (waveform more steady!)
Pic 5: probes at CN13 position from CN6 disconnected . FFT 10Khz
Pic 6: probes at CN13 position from CN6 disconnected . FFT 25Mhz (high freq)
Pic 7: probes at CN13 position from CN6 connected. FFT 10Khz
Pic 8: probes at CN13 position from CN6 connected. FFT 10Khz
Pic 9: probes at CN13 position from CN6 connected. FFT 25Mhz (high freq) (2.2V ac coming true?)
Pic 9: Probes at test point 1 & 2: CN6 Connected. FFT 10Khz
Pic 9: Probes at test point 1 & 2: FFT 25Mhz (high freq)
What can be the cause of this. Maby Brdige rectifier are failing at load or anythin else to concider?
Attachments
Build a FM stereo decoder using chip and tube
- By wa2ise
- Analogue Source
- 141 Replies
This is a FM MPX stereo decoder that uses a stereo chip to acquire the 38KHz switching waveform, and applies that to a "TV" tube that switches on and off the composite audio (which carries both the mono and the L-R difference signals) to produce left and right audio outputs. Idea is to use the chip to get a synchronized switching waveform. And the tube handles the audio signal that will go to your audio amplifier.
First thing is to find a chip that produces a 38KHz switching waveform. Turns out most of these stereo decoder chips don't provide that, keeping this signal inside itself. Some will provide 19KHz, but that's not useful. With my selected chip datasheet TA7343 I can get the 38KHz signal, but only if I don't have it directly drive an indicator LED. Doing that disables the chip's stereo demod section, but I'm not using that here. I found that when this chip loses lock on the stereo pilot signal, this 38KHz output pin goes much higher in voltage, thus I used a buffer circuit to light a "not stereo" LED indicator when that happens. The FM radio station essentially MUXes the left and the right channels by alternating the left and right audio signals at 38KHz rate. Making a sequence of L, R, L, R, etc at this 38KHz rate (time division multiplex) And my circuit recreates this 38KHz switching signal and essentially deMUXes the left from the right. The 6HS8 is a tube meant for color TV work, where this tube splits apart chroma information (which is also a MUXed signal of R-Y and B-Y chroma signals). In my circuit, each grid 3 has a square wave at the 38KHz rate that allows (when near +2V) its audio channel to get to its respective plate, or when this grid goes about -5V negative, cuts off the audio (disabling the audio that belongs to the other channel from reaching this plate). I used an LED to create a fixed bias for this tube, so these levels would always work). The LM393 dual comparitor chip produces 2 38KHz square waves, one inverted (it's essentially a data slicer). These square waves feed the grid 3's after passign thru a "DC restore" circuit that sets the voltage range of these square waves to levels the tube wants (also if stereo lock is lost, this circuit will clamp both signals to an "on" level, thus passing audio to both outputs). Otherwise, the comparitor chip will make a positive level on one output and a negative level on the other, thus cutting off one of the outputs.
I appear to be getting good channel separation, but no, I haven't figured out which channel is the left, and which is the right, just yet! 😀
First thing is to find a chip that produces a 38KHz switching waveform. Turns out most of these stereo decoder chips don't provide that, keeping this signal inside itself. Some will provide 19KHz, but that's not useful. With my selected chip datasheet TA7343 I can get the 38KHz signal, but only if I don't have it directly drive an indicator LED. Doing that disables the chip's stereo demod section, but I'm not using that here. I found that when this chip loses lock on the stereo pilot signal, this 38KHz output pin goes much higher in voltage, thus I used a buffer circuit to light a "not stereo" LED indicator when that happens. The FM radio station essentially MUXes the left and the right channels by alternating the left and right audio signals at 38KHz rate. Making a sequence of L, R, L, R, etc at this 38KHz rate (time division multiplex) And my circuit recreates this 38KHz switching signal and essentially deMUXes the left from the right. The 6HS8 is a tube meant for color TV work, where this tube splits apart chroma information (which is also a MUXed signal of R-Y and B-Y chroma signals). In my circuit, each grid 3 has a square wave at the 38KHz rate that allows (when near +2V) its audio channel to get to its respective plate, or when this grid goes about -5V negative, cuts off the audio (disabling the audio that belongs to the other channel from reaching this plate). I used an LED to create a fixed bias for this tube, so these levels would always work). The LM393 dual comparitor chip produces 2 38KHz square waves, one inverted (it's essentially a data slicer). These square waves feed the grid 3's after passign thru a "DC restore" circuit that sets the voltage range of these square waves to levels the tube wants (also if stereo lock is lost, this circuit will clamp both signals to an "on" level, thus passing audio to both outputs). Otherwise, the comparitor chip will make a positive level on one output and a negative level on the other, thus cutting off one of the outputs.
I appear to be getting good channel separation, but no, I haven't figured out which channel is the left, and which is the right, just yet! 😀
Attachments
Building a High-End midway crossover with WEE Technology - WEET - WMH capacitors
- By Abartels1965
- Multi-Way
- 4 Replies
Hello fellow audiophiles,
I have been building my own speakers and modifying them for many years. The goal is to achieve the most natural sound quality possible, so that the playback is indistinguishable from an unplugged live performance. A loudspeaker should not have its own sound; after all, it is not a musical instrument but a device meant solely for reproduction. One of the most challenging aspects of designing a good loudspeaker is undoubtedly creating an effective crossover filter. It involves not only calculating the perfect values of the components but also making the right component choices.
Over the past years, I have extensively experimented with capacitors, always trying to use the best possible ones. However, high-quality capacitors are quite expensive, and sometimes it's not feasible to use them due to their high cost. I always use film capacitors based on polypropylene in my designs, as electrolytic capacitors are a no-go for speaker crossovers, at least for me. For low frequencies, you often need capacitors with high values, especially in a three-way system like mine. The midrange driver starts around 60Hz, and I let the woofer roll off around 50Hz to avoid interference frequencies. Using really good film capacitors in this scenario can quickly become quite expensive.
In my design, the midrange driver covers a frequency range from 60Hz to 5KHz. It's a very wide range, but the advantage is that almost all critical frequencies are handled by the same speaker driver, eliminating any crossover interference within this range. For the midrange driver, I need a series capacitor of 100uF, which is quite a high value that can't easily be filled with super expensive capacitors if you don't want to spend a fortune.
Until now, I have used a combination of Jantzen Audio Superior-Z and Jantzen Audio Silver-Z, along with bypassing them with Cornell Dubilier 940C 3000V capacitors. This setup already cost me over €450 per midrange driver. Although I'd like to use even better capacitors, options like Alumen-Z would cost around €1000 per midrange driver, which is not doable for me. Therefore, I was thrilled when I came across the brand WEET on an audio forum on the internet. I checked the capacitors they offer and directly contacted Fay through www.musicaps.com. She was very friendly and professional, addressing all my inquiries excellently. Eventually, I chose 20 pieces of 10uF WEET WMH Aluminium capacitors, and we agreed on a price that was feasible for me.
I then spent two days building my two crossover filters on wooden panels, which I mounted on vibration dampers, externally on the back of the speakers.
After completing the setup, I began listening to the speakers. I know that capacitors, and every conductor in general, even a simple copper wire, as well as all the new sockets, plugs, and not to forget the 0.47mH Litz coil placed in series with the capacitors, need a minimum of 150 hours of playtime before they start sounding as they should. Often, the sound quality reaches only 80% to 90% of its potential during that time, depending on the materials used. For instance, Teflon capacitors require half a century of "breaking in," and silver conductors also need several weeks to reach their full potential. However, I started by playing track no. 2 from the IsoTek Full System Enhancer & Rejuvenation Disc, which is a half-hour long track. I knew there would be quite a noticeable difference after playing this track once only. After 30 minutes, I played a piece of music and started listening.
Right from the first notes from my speakers, I was pleasantly surprised! It already sounded significantly better than what I was accustomed to! Over the following week, I let the speakers play continuously at a low volume. During the night and when I was away from home, I used the IsoTek CD, and when I returned from work, I played music. Every day, I heard improvements, and I must admit that I experienced goosebumps several times while listening. These WEET WMH capacitors achieve an unbelievable high sound quality: the openness, depth, and width of the soundstage, the pinpoint precision, and the realism with which the music is reproduced are of such high quality that at times, I genuinely feel like the musicians are performing in my living room. I have never been a huge fan of live recordings; somehow, I found them less natural and was more drawn to studio recordings. However, that has changed completely now! Every live recording I've heard so far has astonished me; the realism is unlike anything I've ever heard before, even with very exotic speakers and expensive sound systems. I can only use superlatives to describe the experience, and that's precisely how I perceive it. Not just me, but all my audiophile friends who come to my place regularly to listen, while enjoying some drinks and snacks, were amazed as well. The most memorable compliment came from one of these friends who said before leaving: "Thank you, Alex." I asked, "Why?" And he replied with a smiling but serious face, "Now I won't be able to listen to my own setup at home for at least a week because it sounds like an old-fashioned transistor radio compared to this."
I've never received a better compliment, and at the end of this rather lengthy review, I want to pass on the same great compliment to WEET and thank them for all the beauty these capacitors will bring me in the coming years!
The WEET WMH capacitors are not just very good; they are a MUST for anyone who needs higher value in capacitance range and wants to build or modify a relatively affordable crossover filter in such a way that there is no doubt about achieving a realistic reproduction. With the WMH capacitors, you can be certain that at least capacitor quality won't be the limiting factor!
Best regards,
Alex
I have been building my own speakers and modifying them for many years. The goal is to achieve the most natural sound quality possible, so that the playback is indistinguishable from an unplugged live performance. A loudspeaker should not have its own sound; after all, it is not a musical instrument but a device meant solely for reproduction. One of the most challenging aspects of designing a good loudspeaker is undoubtedly creating an effective crossover filter. It involves not only calculating the perfect values of the components but also making the right component choices.
Over the past years, I have extensively experimented with capacitors, always trying to use the best possible ones. However, high-quality capacitors are quite expensive, and sometimes it's not feasible to use them due to their high cost. I always use film capacitors based on polypropylene in my designs, as electrolytic capacitors are a no-go for speaker crossovers, at least for me. For low frequencies, you often need capacitors with high values, especially in a three-way system like mine. The midrange driver starts around 60Hz, and I let the woofer roll off around 50Hz to avoid interference frequencies. Using really good film capacitors in this scenario can quickly become quite expensive.
In my design, the midrange driver covers a frequency range from 60Hz to 5KHz. It's a very wide range, but the advantage is that almost all critical frequencies are handled by the same speaker driver, eliminating any crossover interference within this range. For the midrange driver, I need a series capacitor of 100uF, which is quite a high value that can't easily be filled with super expensive capacitors if you don't want to spend a fortune.
Until now, I have used a combination of Jantzen Audio Superior-Z and Jantzen Audio Silver-Z, along with bypassing them with Cornell Dubilier 940C 3000V capacitors. This setup already cost me over €450 per midrange driver. Although I'd like to use even better capacitors, options like Alumen-Z would cost around €1000 per midrange driver, which is not doable for me. Therefore, I was thrilled when I came across the brand WEET on an audio forum on the internet. I checked the capacitors they offer and directly contacted Fay through www.musicaps.com. She was very friendly and professional, addressing all my inquiries excellently. Eventually, I chose 20 pieces of 10uF WEET WMH Aluminium capacitors, and we agreed on a price that was feasible for me.
I then spent two days building my two crossover filters on wooden panels, which I mounted on vibration dampers, externally on the back of the speakers.
After completing the setup, I began listening to the speakers. I know that capacitors, and every conductor in general, even a simple copper wire, as well as all the new sockets, plugs, and not to forget the 0.47mH Litz coil placed in series with the capacitors, need a minimum of 150 hours of playtime before they start sounding as they should. Often, the sound quality reaches only 80% to 90% of its potential during that time, depending on the materials used. For instance, Teflon capacitors require half a century of "breaking in," and silver conductors also need several weeks to reach their full potential. However, I started by playing track no. 2 from the IsoTek Full System Enhancer & Rejuvenation Disc, which is a half-hour long track. I knew there would be quite a noticeable difference after playing this track once only. After 30 minutes, I played a piece of music and started listening.
Right from the first notes from my speakers, I was pleasantly surprised! It already sounded significantly better than what I was accustomed to! Over the following week, I let the speakers play continuously at a low volume. During the night and when I was away from home, I used the IsoTek CD, and when I returned from work, I played music. Every day, I heard improvements, and I must admit that I experienced goosebumps several times while listening. These WEET WMH capacitors achieve an unbelievable high sound quality: the openness, depth, and width of the soundstage, the pinpoint precision, and the realism with which the music is reproduced are of such high quality that at times, I genuinely feel like the musicians are performing in my living room. I have never been a huge fan of live recordings; somehow, I found them less natural and was more drawn to studio recordings. However, that has changed completely now! Every live recording I've heard so far has astonished me; the realism is unlike anything I've ever heard before, even with very exotic speakers and expensive sound systems. I can only use superlatives to describe the experience, and that's precisely how I perceive it. Not just me, but all my audiophile friends who come to my place regularly to listen, while enjoying some drinks and snacks, were amazed as well. The most memorable compliment came from one of these friends who said before leaving: "Thank you, Alex." I asked, "Why?" And he replied with a smiling but serious face, "Now I won't be able to listen to my own setup at home for at least a week because it sounds like an old-fashioned transistor radio compared to this."
I've never received a better compliment, and at the end of this rather lengthy review, I want to pass on the same great compliment to WEET and thank them for all the beauty these capacitors will bring me in the coming years!
The WEET WMH capacitors are not just very good; they are a MUST for anyone who needs higher value in capacitance range and wants to build or modify a relatively affordable crossover filter in such a way that there is no doubt about achieving a realistic reproduction. With the WMH capacitors, you can be certain that at least capacitor quality won't be the limiting factor!
Best regards,
Alex
1kV GU50 PP 100W RMS amplifier from a SINGLE PAIR
- By CaterpilarSK
- Tubes / Valves
- 23 Replies
a year ago I have come across a stash of GU50s. The human brain thinks simple in those situations, see shiny, want shiny, even if it serves no purpose. SO I took em.
Today I have tought to myself, HMMMMM these things are rate 40W anode dissapation Ua1kV and Ik 350mA
I think I can easily pull out 100W RMS out of a single pair. Well, would be easier if I didnt want a UL output transformer with cathode feedback windings too.
Here is the setup:
Yes youre seeing it right, 1kV anode voltage. With this voltage I could probably get into the 130W RMS territory (as the cathode current in this setup is peaking 250mA nowhere near the Ik limit of the tubes)
At this voltage getting acceptable class AB behaviour is not that easy as it requires to drive tubes into 30-35W dissapation but according to the simulator it yealds 2.7%THD at 100W RMS
The parameters for the transformer are
10k Ra-a
30%UL
10%CFB
The one issue I am seeing here is the quite large negative G1 voltage. At very negative voltages grids start to behave like electron deflectors..something like a beamforming electrode but in an undesireable place. I might reconsider what to do about it, either lower Ug2 but then having to drive grids positive. If anyone has experience with such negative bias voltages with these tubes or tubes of any kind, precise values or whereabouts your contribution would be really appreciated.
The exact reason I went with 600V Ug2 was because I didnt want to push grid current into them. The GU50s do however have the magical capabillity of withstanding up to 1W ! of grid 1 dissapation. That is quite insane If you ask me, however G2 dissapation kinda sucks a little. But that is not an issue as my G2 voltages are largely below the anode ones so not much G2 current flows until the anode voltage falls below G2 voltage and then larger current starts to flow which is sorta limited by the 100ohm resistors (while still not impeding gain)
The cathode feedback windings hugely increase the drive requirements right up to 600V p-p. This is certainly a problem to overcome with both a tube or transistor driver. But I have a solution.
This abominaton:
C1 and C2 replace grid cappacitance of GU50s (datasheet maximum value)
At first I did not plan it to come out like this, but I thought "what the hell lets give it a chance anyways"
Interstage transformer with cathode feedback to prevent phase shifting.
Everything is DC coupled, no bass frequency compromises HOWEVER I see a slight issue with this. While the voltage on the anode resistors are going to be fairly predictable thanks to the current sources, if the tubes are mismatched that will cause a current flow difference between one anode to another one and consequently DC current will flow trough the interstage transformer.
I dont know of a small power still manufactured tube that could give me a 600V p-p swing without great distortion, melting it or straight up ripping the emissive coating off the cathodes. So it was either a cascode of I dont know what tube that could also give reasonable drive power without melting, or an interstage transformer. So I thought if I have to use an interstage transformer might aswell overdo it. And that was the result of such thinking.
I dont know the winding ratios yet because I just threw down the priary inductance by gut feeling and then adjusted everyting arround until I got desireable results and gains.
Any feedback on this insanity would be appreciated. Please do leave feedback as I mostly draw this sort of stuff up trought the night half asleep and I might miss some fundamental errors why this cant work or wont work the way I want. Suggestions on how to make it better or fix it if broken are greatly appreciated.
Today I have tought to myself, HMMMMM these things are rate 40W anode dissapation Ua1kV and Ik 350mA
I think I can easily pull out 100W RMS out of a single pair. Well, would be easier if I didnt want a UL output transformer with cathode feedback windings too.
Here is the setup:
Yes youre seeing it right, 1kV anode voltage. With this voltage I could probably get into the 130W RMS territory (as the cathode current in this setup is peaking 250mA nowhere near the Ik limit of the tubes)
At this voltage getting acceptable class AB behaviour is not that easy as it requires to drive tubes into 30-35W dissapation but according to the simulator it yealds 2.7%THD at 100W RMS
The parameters for the transformer are
10k Ra-a
30%UL
10%CFB
The one issue I am seeing here is the quite large negative G1 voltage. At very negative voltages grids start to behave like electron deflectors..something like a beamforming electrode but in an undesireable place. I might reconsider what to do about it, either lower Ug2 but then having to drive grids positive. If anyone has experience with such negative bias voltages with these tubes or tubes of any kind, precise values or whereabouts your contribution would be really appreciated.
The exact reason I went with 600V Ug2 was because I didnt want to push grid current into them. The GU50s do however have the magical capabillity of withstanding up to 1W ! of grid 1 dissapation. That is quite insane If you ask me, however G2 dissapation kinda sucks a little. But that is not an issue as my G2 voltages are largely below the anode ones so not much G2 current flows until the anode voltage falls below G2 voltage and then larger current starts to flow which is sorta limited by the 100ohm resistors (while still not impeding gain)
The cathode feedback windings hugely increase the drive requirements right up to 600V p-p. This is certainly a problem to overcome with both a tube or transistor driver. But I have a solution.
This abominaton:
C1 and C2 replace grid cappacitance of GU50s (datasheet maximum value)
At first I did not plan it to come out like this, but I thought "what the hell lets give it a chance anyways"
Interstage transformer with cathode feedback to prevent phase shifting.
Everything is DC coupled, no bass frequency compromises HOWEVER I see a slight issue with this. While the voltage on the anode resistors are going to be fairly predictable thanks to the current sources, if the tubes are mismatched that will cause a current flow difference between one anode to another one and consequently DC current will flow trough the interstage transformer.
I dont know of a small power still manufactured tube that could give me a 600V p-p swing without great distortion, melting it or straight up ripping the emissive coating off the cathodes. So it was either a cascode of I dont know what tube that could also give reasonable drive power without melting, or an interstage transformer. So I thought if I have to use an interstage transformer might aswell overdo it. And that was the result of such thinking.
I dont know the winding ratios yet because I just threw down the priary inductance by gut feeling and then adjusted everyting arround until I got desireable results and gains.
Any feedback on this insanity would be appreciated. Please do leave feedback as I mostly draw this sort of stuff up trought the night half asleep and I might miss some fundamental errors why this cant work or wont work the way I want. Suggestions on how to make it better or fix it if broken are greatly appreciated.
Question for 2nd order Butterworth XO
- By Captn Dave
- Multi-Way
- 5 Replies
I’m trying to calculate the crossover frequency for an existing crossover, which I know how to do with a simple LC design but I’m not sure how to treat the series resistors in this design. Do I add the resistances in with the impedances and look for the frequency where the sum of R+Ic is equal to the impedance of the inductor+its R? Is there more to it. Why would one design it this way? Thanks
Jazzman"s ripole with Faital 12pr320
- By diyiggy
- Subwoofers
- 0 Replies
Hello there,
I had a strange idea at looking the spec of the Peereless SLS-12, used in the famous Jazzman ripole.
Here is the TS spec measured by a Dibirama website . Qts : 0.52 ; Fs :30 Hz , Xmax : 8 mm ; sensivity higher than the datasheet with 91.5/2.83V.
The PA Faital 12PR320, a more a pro midwoofer than a woofer, falls faster than the SL-12 below 100 hz.
It has 93dB/2.83V at 100 Hz, 2 dB more than the Peereless here; 85 dB at 50 Hz (IEC Baffle) only but it is what showing also the peereless SLS-12 datasheet.
The ripoles circa extend the Fs by -10 Hz and drops the sensivity by 10 to 11 dB. The Faital has 42 Hz Fs. In ripole it means around 32 Hz
Xmax between the two drivers being quite equal, minus the worse Qts of the Faital 12PR320 : 0.38/0.40 in real life ; do you think it is feasible to use two Faitals 12PR320 for a Jazmann's ripole if two Sub in the room ? The EBP of the 12PR320 is 100, twice than the Peereless, so theorically more made for vented.
Thanks
Edit, is there a way to sim that. I only know Vtuix Cad, not an easy task but playing with the baffle step option to reduce the baffle at the size of the driver and click to x2 driver and seewhat the baffle step loss could be as an open baffle (I get -11 dB at 40 hz...) but the only OB sim I have is with an infinite baffle (I assume IEC baffle dimension for Vituix compute)
I had a strange idea at looking the spec of the Peereless SLS-12, used in the famous Jazzman ripole.
Here is the TS spec measured by a Dibirama website . Qts : 0.52 ; Fs :30 Hz , Xmax : 8 mm ; sensivity higher than the datasheet with 91.5/2.83V.
The PA Faital 12PR320, a more a pro midwoofer than a woofer, falls faster than the SL-12 below 100 hz.
It has 93dB/2.83V at 100 Hz, 2 dB more than the Peereless here; 85 dB at 50 Hz (IEC Baffle) only but it is what showing also the peereless SLS-12 datasheet.
The ripoles circa extend the Fs by -10 Hz and drops the sensivity by 10 to 11 dB. The Faital has 42 Hz Fs. In ripole it means around 32 Hz
Xmax between the two drivers being quite equal, minus the worse Qts of the Faital 12PR320 : 0.38/0.40 in real life ; do you think it is feasible to use two Faitals 12PR320 for a Jazmann's ripole if two Sub in the room ? The EBP of the 12PR320 is 100, twice than the Peereless, so theorically more made for vented.
Thanks
Edit, is there a way to sim that. I only know Vtuix Cad, not an easy task but playing with the baffle step option to reduce the baffle at the size of the driver and click to x2 driver and seewhat the baffle step loss could be as an open baffle (I get -11 dB at 40 hz...) but the only OB sim I have is with an infinite baffle (I assume IEC baffle dimension for Vituix compute)
Audio Technica AT-1010 Tonearm Rebuild and Upgrades
- By jamie123
- Analogue Source
- 64 Replies
Audio Technica AT-1010 Tonearm Rebuild and Upgrades.
Having owned a PMAT-101O for some years i recently bought a used standard AT-1010 with the intentions of
rebuilding it and where i can upgrading the components.If i can match the high performance of the PMAT version i'll
be a happy bunny!
Here is the tonearm stripped into all its pieces.
The first job i wanted to tackle is to make a new bearing housing spindle bolt.The original one has a loose fit where the horizontal bearings run so i made mine with a tighter
tolerance.
The original.
8mm diameter head turned and then 6mm diameter turned for m6 thread.
Thread cut.
Here's the old with the new one which also has a 4mm hole drilled up its length for the tonearm wires to pass through.
Having owned a PMAT-101O for some years i recently bought a used standard AT-1010 with the intentions of
rebuilding it and where i can upgrading the components.If i can match the high performance of the PMAT version i'll
be a happy bunny!
Here is the tonearm stripped into all its pieces.
The first job i wanted to tackle is to make a new bearing housing spindle bolt.The original one has a loose fit where the horizontal bearings run so i made mine with a tighter
tolerance.
The original.
8mm diameter head turned and then 6mm diameter turned for m6 thread.
Thread cut.
Here's the old with the new one which also has a 4mm hole drilled up its length for the tonearm wires to pass through.
Hello from PA
- By Stiglite
- Introductions
- 1 Replies
Hello all,
I have joined this forum so I can learn and or possibly help someone else on the never ending audio journey. My current system...
Yamaha RX-A8A in a 7.2.4 setup
Macintosh MC7106 powers the surrounds
Proceed HPA 3 triple mono powers the front and center channels
Polk R700 mains, R400 center, R200 rear surrounds.
In wall side surrounds 3 way monolith 8"
4 8" Monolith angled Atmos speakers
1 Rythmik FV18
1 Bic 12"
LG 65 Oled inch TV
My next project is to build 2 subwoofers. I have been considering a couple Mini Marty's with the new Ultimax or possibly the Stereo Integrity HST18.
This site is a great resource of information and I'm looking learning new things and enjoying the journey..
I have joined this forum so I can learn and or possibly help someone else on the never ending audio journey. My current system...
Yamaha RX-A8A in a 7.2.4 setup
Macintosh MC7106 powers the surrounds
Proceed HPA 3 triple mono powers the front and center channels
Polk R700 mains, R400 center, R200 rear surrounds.
In wall side surrounds 3 way monolith 8"
4 8" Monolith angled Atmos speakers
1 Rythmik FV18
1 Bic 12"
LG 65 Oled inch TV
My next project is to build 2 subwoofers. I have been considering a couple Mini Marty's with the new Ultimax or possibly the Stereo Integrity HST18.
This site is a great resource of information and I'm looking learning new things and enjoying the journey..
