Old-fashioned amplifiers with a new twist (1)
- By Elvee
- Solid State
- 65 Replies
Some time ago, Daniel asked me if I could design "discrete chipamps", ie. amplifiers as simple, tolerant and easy as chipamps, but completely discrete in the seventies style, and with additional constraints: single-supply, no LTP, no unusual parts like lat-FETs and transistor count < 9.
Here is the result for the lite version: ~0 to 25W output.
It is the base circuit: the circuit lends itself to various modifications and improvements (will be described later).
It is built to be highly flexible and tolerant: it was initially designed for supply voltages ranging from 3.3V to 24V without any component change, but it can in fact work from less than 3V to more than 30V if the capacitors have a sufficient voltage rating.
All components are non-critical, and it can work with cheap internet parts (my prototype uses some).
The performances are not exceptional, but they are decent enough for such a small circuit, and normally sufficient for most applications.
Since the thermal compensation/quiescent current is always a delicate issue for DIY amps, it uses an automatic class-B bias engine: no adjustment, and only basic thermal coupling is required (this can even be dispensed with completely, more on that later).
The efficiency is also quite good: with a 19V supply, it manages to deliver 18Vpp into a 4Ω load.
The schematic and sim use the D44/D45 OP pair, because it was a preference of Daniel, but in my build I used a BD435 from ST and a BD438 from Philips. Not the best match, but it works with this amp. The VAS is not a BC337, but a CN made S8050.
The simmed THD is 0.04%, against 0.05% in reality.
The power bandwidth exceeds 300kHz.
Here is a pic of the prototype:
And here is the 10kHz, large-signal squarewave response:
Here is the result for the lite version: ~0 to 25W output.
It is the base circuit: the circuit lends itself to various modifications and improvements (will be described later).
It is built to be highly flexible and tolerant: it was initially designed for supply voltages ranging from 3.3V to 24V without any component change, but it can in fact work from less than 3V to more than 30V if the capacitors have a sufficient voltage rating.
All components are non-critical, and it can work with cheap internet parts (my prototype uses some).
The performances are not exceptional, but they are decent enough for such a small circuit, and normally sufficient for most applications.
Since the thermal compensation/quiescent current is always a delicate issue for DIY amps, it uses an automatic class-B bias engine: no adjustment, and only basic thermal coupling is required (this can even be dispensed with completely, more on that later).
The efficiency is also quite good: with a 19V supply, it manages to deliver 18Vpp into a 4Ω load.
The schematic and sim use the D44/D45 OP pair, because it was a preference of Daniel, but in my build I used a BD435 from ST and a BD438 from Philips. Not the best match, but it works with this amp. The VAS is not a BC337, but a CN made S8050.
The simmed THD is 0.04%, against 0.05% in reality.
The power bandwidth exceeds 300kHz.
Here is a pic of the prototype:
And here is the 10kHz, large-signal squarewave response:
Attachments
Sony HiFi RV22 - STK 403-130 Question
- Chip Amps
- 3 Replies
Hi Members
I am new here and I have a few questions regarding the Sony HiFi RV22 - STK 403-130.
I am going to run this Amp separately and I wanted to know about feeding Input voltages, I have attached AMP schematic view.
Numbers Marked Red
1 - What voltage should I input for running 3 number Relay and where from I get that voltage.
2 - How much voltage should I input to mute the sound?
Answers will be really appreciated.
I am new here and I have a few questions regarding the Sony HiFi RV22 - STK 403-130.
I am going to run this Amp separately and I wanted to know about feeding Input voltages, I have attached AMP schematic view.
Numbers Marked Red
1 - What voltage should I input for running 3 number Relay and where from I get that voltage.
2 - How much voltage should I input to mute the sound?
Answers will be really appreciated.
Best Antenna for Marantz 2500 + Pioneer sx- 1980 Receivers
- Analogue Source
- 9 Replies
Does anyone know where you can purchase a good antenna fpr these 2 receivers? I own both of these receivers, and had them fully restored, but where can find a good quality FM external antenna for the both of them? Does anyone sell them online?
EU. Nottingham Analogue Spacedeck+Koetsu Black
Hi just looking if there is some serius interest 2,5k€
ADAU1701 based DSP for sub or 2 way
- By Baldin
- Digital Line Level
- 90 Replies
Happy New Year 🙂
Starting the new year and decade playing a bit with DSP.
Have bought a Sure DSP and programmer board, and gotten familiar with SigmaStudio.
Time to do my own 😉
Would highly appreciate a review for any mistakes or misunderstandings I might have made, by someone much more experienced in ADAU1701 design than myself.
I can make PCB design available if interested ... when I get that far 😉
Design based on ADAU1701 obviously, and NCS2632 to allow for pop free operation.
The output is enabled by a voltage monitor, TCM809TENB713.
I have included 3 general use pots for control, and 3 LEDs for especially peak indicators.
Output 0 and 1 are additionally run through a 10k log pot, for use with e.g. a sub amplifier directly, or my coming party box a la "Soundboks"
There is an extension port which is intended to be used for additional or alternative DAC / Codec. I have not included the I2C signals though, which is otherwise the normal for e.g. FreeDSP ... can't really see the use ... but correct me if I'm wrong on this.
/Baldin
Starting the new year and decade playing a bit with DSP.
Have bought a Sure DSP and programmer board, and gotten familiar with SigmaStudio.
Time to do my own 😉
Would highly appreciate a review for any mistakes or misunderstandings I might have made, by someone much more experienced in ADAU1701 design than myself.
I can make PCB design available if interested ... when I get that far 😉
Design based on ADAU1701 obviously, and NCS2632 to allow for pop free operation.
The output is enabled by a voltage monitor, TCM809TENB713.
I have included 3 general use pots for control, and 3 LEDs for especially peak indicators.
Output 0 and 1 are additionally run through a 10k log pot, for use with e.g. a sub amplifier directly, or my coming party box a la "Soundboks"
There is an extension port which is intended to be used for additional or alternative DAC / Codec. I have not included the I2C signals though, which is otherwise the normal for e.g. FreeDSP ... can't really see the use ... but correct me if I'm wrong on this.
/Baldin
Testing for SuperReg-2020
- By WaltJ
- The diyAudio Store
- 10 Replies
This thread is split from:Super Regulator
____________________________________________________________________________
I am uploading my preview document for a tester useful towards exercising SR circuits. It offers useful info on cap ESR and regulator Zout, using the AD825 in a SR2020 circuit.
It will also be available from my website via this link.
Walt Jung
FS: Yamaha C-4 preamplifier
I am selling my Yamaha C-4 preamplifier.
Is in good working condition and no intervention was made inside. All the components are the original ones.
For more details, please send me a private message.
The price is 550 euro + shipping (around 35 euro). Payment via paypal.
I am sending in EU only.
Is in good working condition and no intervention was made inside. All the components are the original ones.
For more details, please send me a private message.
The price is 550 euro + shipping (around 35 euro). Payment via paypal.
I am sending in EU only.
Online shop for ribbons
- By dahlberg
- Vendor's Bazaar
- 6 Replies
So I have been doing this for a while now and I thought that I might just as
well set up shop. In doing so I figured I should ask potential customers before
hand what I should keep "on the shelf". So if you have nothing better to do, I
would appreciate specs for what you might order in the future.
There are a few examples at the store already, some might be around and
some might be replaced. There is always a possibility to order "custom ribbons"
but if it's on "on the shelf" it will ship the next day from order.
Custom orders will usually ship within a week or two.
Best regards: Bengt Dahlberg
DahlbergAudioDesign
well set up shop. In doing so I figured I should ask potential customers before
hand what I should keep "on the shelf". So if you have nothing better to do, I
would appreciate specs for what you might order in the future.
There are a few examples at the store already, some might be around and
some might be replaced. There is always a possibility to order "custom ribbons"
but if it's on "on the shelf" it will ship the next day from order.
Custom orders will usually ship within a week or two.
Best regards: Bengt Dahlberg
DahlbergAudioDesign
Horning Alkibiades - Fullrange with very high frequency Tweeter ? - Crossover Network
- Full Range
- 13 Replies
Attachments
-
Locked
How to attach images to your posts in XF
- By Mooly
- Forum Problems & Feedback
- 0 Replies
How to attach images and files to a post is a question that repeatedly crops up. Hopefully as this quick tutorial will show the process is quick and easy.
Go to the following options depending on what you want to do.
Option 1. To insert a single image or a group of images.
Option 2. To insert an image from a web page.
Option 3. To add non standard files. These would be ones having file extensions not natively handled by the forum.
We would also ask that wherever possible you make full use of the forums imaging handling and storage facilities rather than just linking to a set of images held on a 3rd party hosting site. The reason is that these 3rd party images usually don't last for long as the poster either deletes them at some future time or the account holding them falls into disuse. We want your work to be here forever. XF (XenForo) the platform that we are now using has far better image handling than the old site.
Option 1: Attaching an image or a file stored locally on your PC.
To do this simply click the 'Attach Files' button at the bottom of the message reply box. This will open a Window that will allow you to browse your PC for the images or files you want to add.
Note. XF allows for multiple image uploads. Simply select all the images needed and click on 'Open' when you have have them all.
Or you can click the Image button here.
For example five images have been selected here. Having selected the image or images or file select Open. All the images selected will now load to the site.
Having now got the images uploaded to the site they now have to be added to your post. If you click 'Insert Multiple' then a new set of options will appear and which are fairly self explanatory.
Each image has a 'tick box' in its top left corner. The options on the toolbar below the images allows you to select them all as a group or individually and also gives the option of how you want them to appear, either as thumbnails or a full image in the body of the post.
If you have uploaded just a single image then these options appear in the uploaded preview image.
An inline image is inserted at whatever point you have the cursor.
Note. Once an image is selected you also have the option to delete that image off the system which is useful if you uploaded something in error. The 'Bin' icon on the tool bar is active once you select at least one image.
You can also individually decide for each image by clicking the 'Insert Image' text on the preview images. This will then open to give you a choice.
-----------------------------------------------------------
Option 2: Adding an image direct from a Web page.
Providing the image is within the forums max size limitations and is of a file extension allowable then you can simply copy and paste that image into a post. The insertion point will be wherever your cursor is in you post.
You can also Drag and Drop images into a post from different sources. For example a second open browser window or your PC itself.
The same also applies to images on your PC. You can also just copy and paste these into a post.
------------------------------------------------------------
Option 3: To add non standard files. Use this option when the file/s you wish to upload have file extensions not recognised by the forum.
Placing any such files into a Zipped Folder and uploading the whole folder will allow you to add non standard files to your posts.
Go to the following options depending on what you want to do.
Option 1. To insert a single image or a group of images.
Option 2. To insert an image from a web page.
Option 3. To add non standard files. These would be ones having file extensions not natively handled by the forum.
We would also ask that wherever possible you make full use of the forums imaging handling and storage facilities rather than just linking to a set of images held on a 3rd party hosting site. The reason is that these 3rd party images usually don't last for long as the poster either deletes them at some future time or the account holding them falls into disuse. We want your work to be here forever. XF (XenForo) the platform that we are now using has far better image handling than the old site.
Option 1: Attaching an image or a file stored locally on your PC.
To do this simply click the 'Attach Files' button at the bottom of the message reply box. This will open a Window that will allow you to browse your PC for the images or files you want to add.
Note. XF allows for multiple image uploads. Simply select all the images needed and click on 'Open' when you have have them all.
Or you can click the Image button here.
For example five images have been selected here. Having selected the image or images or file select Open. All the images selected will now load to the site.
Having now got the images uploaded to the site they now have to be added to your post. If you click 'Insert Multiple' then a new set of options will appear and which are fairly self explanatory.
Each image has a 'tick box' in its top left corner. The options on the toolbar below the images allows you to select them all as a group or individually and also gives the option of how you want them to appear, either as thumbnails or a full image in the body of the post.
If you have uploaded just a single image then these options appear in the uploaded preview image.
An inline image is inserted at whatever point you have the cursor.
Note. Once an image is selected you also have the option to delete that image off the system which is useful if you uploaded something in error. The 'Bin' icon on the tool bar is active once you select at least one image.
You can also individually decide for each image by clicking the 'Insert Image' text on the preview images. This will then open to give you a choice.
-----------------------------------------------------------
Option 2: Adding an image direct from a Web page.
Providing the image is within the forums max size limitations and is of a file extension allowable then you can simply copy and paste that image into a post. The insertion point will be wherever your cursor is in you post.
You can also Drag and Drop images into a post from different sources. For example a second open browser window or your PC itself.
The same also applies to images on your PC. You can also just copy and paste these into a post.
------------------------------------------------------------
Option 3: To add non standard files. Use this option when the file/s you wish to upload have file extensions not recognised by the forum.
Placing any such files into a Zipped Folder and uploading the whole folder will allow you to add non standard files to your posts.
High Frequency PCB Manufacturing | Professional Solution Experts | DFX
- Vendor's Bazaar
- 1 Replies
Hi, here is PCBONLINE, a high-frequency PCB manufacturer. Finding a reliable manufacturer is the key step to making sure no issues in high-frequency PCB.
PCBONLINE will:
Help you solve any issues in your PCBs and provide one-on-one engineering support;
Help you choose appropriate base materials of stable and low DK/Df with the highest cost-effectiveness;
Manufacture high-speed/high-frequency PCBs of 4 to 8 layers;
Achieve RF interface and signal interface on the same high-frequency circuit board;
Provide free design for excellence for your projects and make sure to yield successful results.
Visit PCBONLINE' high-frequency webpage: High-Frequency PCB Manufacturing 100% Successful - From Materials to Assembly
Contact us by email: info@pcbonline.com.
Or feel no worry to contact us online!
PCBONLINE will:
Help you solve any issues in your PCBs and provide one-on-one engineering support;
Help you choose appropriate base materials of stable and low DK/Df with the highest cost-effectiveness;
Manufacture high-speed/high-frequency PCBs of 4 to 8 layers;
Achieve RF interface and signal interface on the same high-frequency circuit board;
Provide free design for excellence for your projects and make sure to yield successful results.
Visit PCBONLINE' high-frequency webpage: High-Frequency PCB Manufacturing 100% Successful - From Materials to Assembly
Contact us by email: info@pcbonline.com.
Or feel no worry to contact us online!
Dayton B652 Air Outdated BSC crossover mod
I was recently gifted with a pair of the Dayton B652 Air bookshelf speakers.
They sounded like they have potential, but the treble is at dentistry levels of brightness. Plus cone breakup, etc etc...
So I looked for various crossover mods. This is the one I thought was the smartest way to go:
Fun with the Dayton B652-AIR -
Techtalk Speaker Building, Audio, Video Discussion Forum
So I ordered the parts.
I figured it should still work since the B652s still come with the same crossover components as the modder reported.
However it seems this mod is out of date, as well as the data from the Noaudiophile review. When I measured the speakers with and without the tweeter reversed, the result was almost identical (although the Noaudiophile DSP correction file has the cone mode filter in the right place).
The B652s have been revised in the past, IIRC the woofer cone depth was changed and the crossover was also changed.
In any case, the mod seems to be a reasonable starting point. The first thing I had to do was add a 2.2uF capacitor in parallel with the 4.7uF in order to shift the resonance filter to the new cone mode frequency.
However I'm left with a notch at the crossover frequency. I figured I would post this before finishing in case someone has already got this sorted out or takes one look and knows what to do.
Here is the original BSC mod:
First line is stock B652 with the BSC mod.
Second line is with tweeter reversed.
3rd line is with 2.2uF added in parallel with the 4.7uF cap to get the correct resonance frequency.
So, any thoughts on the best way to fix the notch? It seems changing the 2.2uF cap is the first thing to try...
They sounded like they have potential, but the treble is at dentistry levels of brightness. Plus cone breakup, etc etc...
So I looked for various crossover mods. This is the one I thought was the smartest way to go:
Fun with the Dayton B652-AIR -
Techtalk Speaker Building, Audio, Video Discussion Forum
So I ordered the parts.
I figured it should still work since the B652s still come with the same crossover components as the modder reported.
However it seems this mod is out of date, as well as the data from the Noaudiophile review. When I measured the speakers with and without the tweeter reversed, the result was almost identical (although the Noaudiophile DSP correction file has the cone mode filter in the right place).
The B652s have been revised in the past, IIRC the woofer cone depth was changed and the crossover was also changed.
In any case, the mod seems to be a reasonable starting point. The first thing I had to do was add a 2.2uF capacitor in parallel with the 4.7uF in order to shift the resonance filter to the new cone mode frequency.
However I'm left with a notch at the crossover frequency. I figured I would post this before finishing in case someone has already got this sorted out or takes one look and knows what to do.
Here is the original BSC mod:
First line is stock B652 with the BSC mod.
Second line is with tweeter reversed.
3rd line is with 2.2uF added in parallel with the 4.7uF cap to get the correct resonance frequency.
So, any thoughts on the best way to fix the notch? It seems changing the 2.2uF cap is the first thing to try...
Attachments
ONKYO 10cm Full Range Speaker Project from magazine appendix Year 2021
- By ricyuyc
- Full Range
- 89 Replies
Just received and I am very exciting for upcoming build
ONTOMO MOOK「これならできる」シリーズ2021年版
ONTOMO MOOK「これならできる」シリーズ2021年版、予約開始！ | stereo BLOG
ONTOMO MOOK「これならできる」シリーズ2021年版
ONTOMO MOOK「これならできる」シリーズ2021年版、予約開始！ | stereo BLOG
Signal direction of RCA from AQ are wrong or I'm wrong
Hi there
I bought 1set(R,L) of 2meter RCA cable. I want to split them to 2 sets (1meter each) so I cut them in half and to expect to see 2 wires and a shield. Instead I found 3 wires and a shield. That would be no problem to reconnect to new RCA jack just to use multi-meter to test how they are wired for each. But what I found is strange, each cable (R and L) are difference wired.
In the photo there are yellow, white, blue and shield. Same direction arrows but the White arrow jack: all white, blue wire and shield are connected to jack ground.
While the Black arrow jack: only white wire is connected to jack ground. 😕
For this side of arrow, both cable had same wired: white and blue are connected to jacks ground (no shield connect)
Is this factory or something?😕
If mistake by factory, any one know how to correct them or how to connect for each direction? For 3 wires and a shield?
(For 2 wires and a shield: one wire should combine to shield at one end and separate at the other end. )
I bought 1set(R,L) of 2meter RCA cable. I want to split them to 2 sets (1meter each) so I cut them in half and to expect to see 2 wires and a shield. Instead I found 3 wires and a shield. That would be no problem to reconnect to new RCA jack just to use multi-meter to test how they are wired for each. But what I found is strange, each cable (R and L) are difference wired.
In the photo there are yellow, white, blue and shield. Same direction arrows but the White arrow jack: all white, blue wire and shield are connected to jack ground.
While the Black arrow jack: only white wire is connected to jack ground. 😕
For this side of arrow, both cable had same wired: white and blue are connected to jacks ground (no shield connect)
Is this factory or something?😕
If mistake by factory, any one know how to correct them or how to connect for each direction? For 3 wires and a shield?
(For 2 wires and a shield: one wire should combine to shield at one end and separate at the other end. )
Perry Babin ORION DIN Bridging Module Question?
1. Perry on the op-amp pin 1 and 2 would that possible be connected to DIN plug pin 2 for shielding?
2. Perry are the capacitors within the DIN needed?
2. Perry are the capacitors within the DIN needed?
Attachments
Interesting GM70 scheme... Some questions on the PSU, who helps me please?
- By Michelag
- Tubes / Valves
- 197 Replies
Hi,
i was looking for a good GM70 SE project, and stumbled upon this blog:
GM-70 SE amplifier | Firebottles!
All the credits go to the Blog owner, named Vincet Duparc (still wonder whether he's on the forum?).
I tried to comment on his blog, but no answer came, perhaps these pages are no more curated.
Well, the PSU seems very well designed, regulated but no stabilized, but there are some components that are quite uncanny to me (what they are, how are they controlled.).
In the second attached schematic, the PSU, I circled in red my doubts:
i) I see two relays on the HT primary, one "tempo" shoud be a time delay one, that will be shorting out R27; same should apply to the inrush current limiter that shorts out the thermistor NTC2. Am I right? I think they should be 250VAC/3A, right?
ii) what are these F7/F8/F9 points before each mosfet ?
iii) in the second attached picture, there is another inrush relay that will short out NTC1, and ok, same as before.
In his blog pages, third schematic, there's an arduino controller for temperature and gm70 bias current (third attached picture). This drives a cascaded darlington ULN2003, that controls three relays, one for power, two for inrush limiting.
iv) are these three relays the same in the PSU schematic? I wonder why, if the controller switches them open, there still will be thermistors through which current flows... What am I missing?
If this is not the case (these 3 relays are not the ones in the PSU), where are these relays attached to?
I mean, the arduino schematic rationale seems to me as being 10V in, inputs from thermo sensors, inputs from bias current, and output what?
I really hope you can help me open my eyes, safety is always not enough with handling 1,1kV....
a big thank you!
Mike.
i was looking for a good GM70 SE project, and stumbled upon this blog:
GM-70 SE amplifier | Firebottles!
All the credits go to the Blog owner, named Vincet Duparc (still wonder whether he's on the forum?).
I tried to comment on his blog, but no answer came, perhaps these pages are no more curated.
Well, the PSU seems very well designed, regulated but no stabilized, but there are some components that are quite uncanny to me (what they are, how are they controlled.).
In the second attached schematic, the PSU, I circled in red my doubts:
i) I see two relays on the HT primary, one "tempo" shoud be a time delay one, that will be shorting out R27; same should apply to the inrush current limiter that shorts out the thermistor NTC2. Am I right? I think they should be 250VAC/3A, right?
ii) what are these F7/F8/F9 points before each mosfet ?
iii) in the second attached picture, there is another inrush relay that will short out NTC1, and ok, same as before.
In his blog pages, third schematic, there's an arduino controller for temperature and gm70 bias current (third attached picture). This drives a cascaded darlington ULN2003, that controls three relays, one for power, two for inrush limiting.
iv) are these three relays the same in the PSU schematic? I wonder why, if the controller switches them open, there still will be thermistors through which current flows... What am I missing?
If this is not the case (these 3 relays are not the ones in the PSU), where are these relays attached to?
I mean, the arduino schematic rationale seems to me as being 10V in, inputs from thermo sensors, inputs from bias current, and output what?
I really hope you can help me open my eyes, safety is always not enough with handling 1,1kV....
a big thank you!
Mike.
Questions ideas regarding waveguids // port design t-line
- Full Range
- 10 Replies
Hello there,
I´m back with a few general Questions considering T-Line design and some other stuff as well.
I play around with Hornresp, and came up with to designs I wanted to try.
I build tow Test speakers, and experimented with different cross sections and “Tapers”.
One Speaker is tuned to 95Hz
: it is the winner in a direct sound comparison between those tow, got better dynamic range and the sound apers to be more open, all thou a tiny bit more “blurry” but all the details are there. The other one has a less dynamic and the sound is more concentrated in a small spot, but the detail´s seem to be more pronounced this one is tuned to 109Hz
.
A Few things must be said first:
-the sound only was quantifyed by hearing
-the speakers do have different tuning and maze-layouts
-the enclosures where designed to be operated with filling, but I didden´t do that... big dump
These tow speakers led to a few Question and ideas which I hope to be somewhat constructive.
First of all doas the maze layout affect the sound, sure it doas:
But could it be in some way desirable to have a symmetrical-ich layout of the maze next to the speaker. (since the better sounding one of my speakers cinda is symmetrical while the other is not, could this be one of the )many( reasons). This assumption seems intuitif right but is it thou?
=>Should I design my next test subject in a symmetrical way or is that irrelevant?
How doas sound travel through corners: (illustrated with drawing for better understanding)
a: doas it travel the way with half the radii?
b: doas it teak the way with the radii where both left and right volumes are the same?
c: neither of those
What effective distance sound travels in “corners” and how is it calculated?
(The final speaker´s are required to be very space effective. Having the sound travel a grater distance in “corners” than I´v assumed would play in my favoured)
i`ve been going with a: but now b: sound´s moor plausible to me
Tapering the Port: (sketch fore better understanding)
making “corners” tapered is quit hard to accomplish but having a linear taper along the way is also difficult fore me to accomplish. So here I wanted to check if the way I plan to integrate tapers in my design is applicable.
a: ideal Taper
b: this is how I tested Tapers in my speakers
c: this is how i´m going to design the tapers into the speakers
My design:
-As mentioned no “corners” are tapered (blue in sketch)
-I divide the port in 6 sections where each section is a different length
-The volume each taper teaks away from the maze is identical
i`m going with it any way except it is a super bad thing to do, but I imagen this being good enough.
How about putting waves into the waveguides edges: (with sketch)
This approach is normally used to lover the pressure level´s of a port do to the increased surface area. I´m wondering if such design could help reduce resonance or benefit sound in any other way. I could Imagen that such a waveguide design increases the bandwidth the port covers do to the on some parts increased/lovered distance the sound has to travel?
Or dosen´t it affect sound at all?
Would be nice if you could share your thoughts or experience on this.
If anything is known abut the effects of such waveguide edges is known pleas let me kno.
Thanks for making it this fare, You are encouraged to share your thoughts on every thing I mentioned above.
Thanks fore reading, have an awesome day.
I´m back with a few general Questions considering T-Line design and some other stuff as well.
I play around with Hornresp, and came up with to designs I wanted to try.
I build tow Test speakers, and experimented with different cross sections and “Tapers”.
One Speaker is tuned to 95Hz
: it is the winner in a direct sound comparison between those tow, got better dynamic range and the sound apers to be more open, all thou a tiny bit more “blurry” but all the details are there. The other one has a less dynamic and the sound is more concentrated in a small spot, but the detail´s seem to be more pronounced this one is tuned to 109Hz
.A Few things must be said first:
-the sound only was quantifyed by hearing
-the speakers do have different tuning and maze-layouts
-the enclosures where designed to be operated with filling, but I didden´t do that... big dump
These tow speakers led to a few Question and ideas which I hope to be somewhat constructive.
First of all doas the maze layout affect the sound, sure it doas:
But could it be in some way desirable to have a symmetrical-ich layout of the maze next to the speaker. (since the better sounding one of my speakers cinda is symmetrical while the other is not, could this be one of the )many( reasons). This assumption seems intuitif right but is it thou?
=>Should I design my next test subject in a symmetrical way or is that irrelevant?
How doas sound travel through corners: (illustrated with drawing for better understanding)
a: doas it travel the way with half the radii?
b: doas it teak the way with the radii where both left and right volumes are the same?
c: neither of those
What effective distance sound travels in “corners” and how is it calculated?
(The final speaker´s are required to be very space effective. Having the sound travel a grater distance in “corners” than I´v assumed would play in my favoured)
i`ve been going with a: but now b: sound´s moor plausible to me
Tapering the Port: (sketch fore better understanding)
making “corners” tapered is quit hard to accomplish but having a linear taper along the way is also difficult fore me to accomplish. So here I wanted to check if the way I plan to integrate tapers in my design is applicable.
a: ideal Taper
b: this is how I tested Tapers in my speakers
c: this is how i´m going to design the tapers into the speakers
My design:
-As mentioned no “corners” are tapered (blue in sketch)
-I divide the port in 6 sections where each section is a different length
-The volume each taper teaks away from the maze is identical
i`m going with it any way except it is a super bad thing to do, but I imagen this being good enough.
How about putting waves into the waveguides edges: (with sketch)
This approach is normally used to lover the pressure level´s of a port do to the increased surface area. I´m wondering if such design could help reduce resonance or benefit sound in any other way. I could Imagen that such a waveguide design increases the bandwidth the port covers do to the on some parts increased/lovered distance the sound has to travel?
Or dosen´t it affect sound at all?
Would be nice if you could share your thoughts or experience on this.
If anything is known abut the effects of such waveguide edges is known pleas let me kno.
Thanks for making it this fare, You are encouraged to share your thoughts on every thing I mentioned above.
Thanks fore reading, have an awesome day.
Is This XE350 (XE350C) PCB Worth Building? (Class AB or A Based On Accuphase???)
- By kozard
- Solid State
- 8 Replies
Attachments
Low voltage input stage in a high voltage railed amplifier.
- By edbarx
- Solid State
- 5 Replies
Attachments
FS: DCB1+toroidal
- By factory2nd
- Swap Meet
- 7 Replies
Up for sale a barely used DCB1+power transformer 15-0-15 and little more than 1Kg, asked 150€+shipping at cost!
EL34/KT66/6L6 push pull pair monoblock project
- By Rootz
- Tubes / Valves
- 37 Replies
As of lately I've been sourcing some parts for a new project after last years build of a Baby Huey. To drive my not so efficient Scan-speaks I aimed for a pair of bigger bottle tubes and around 30 to 40 Watts.
Here's what I've got so far:
-2 pcs. 300,275,250-0-250,275,300 @ 250mA and 6.3V @ 5A power transformers;
-2 pcs. Lundahl LL1663-pp 5k to 8 Ohm.
After reading a lot of posts by SY, Tubelab and Gingertube about Source followers right in front of the power tubes and their positive effects on several areas, there will be SF's in all of the following designs.
All designs are PCB based, but build in building blocks. This way I can easily swap boards to compare and listen to the different designs whilst only having to solder few wires. I intend to order all boards to be able to do this.
I've tried to implement a standard way of working when laying out the PCB's: some sort of star ground, keeping low level traces away from high current ones, keeping leads/traces short. As I'm pretty new to designing PCB's for tube amps, I'm fairly certain that there are some improvements to be made. Please feel free to make suggestions.
Let's have a look at the designs. Let me first say there is nothing new under the sun here for most part.
First up is a ST-70 lookalike with a ECF80/6BL8 (cheap!) and SF's.
Second is a Mullard 5-20/Claus Byrith 4-30 variant. O. Schade feedback and a CCS for the phase splitter are added, because I tend to like the sound of those circuits. Triode connected EF86/EF184 (components should be adjusted) and 12AU7 phase splitter, thus moderate levels of global negative feedback can be employed without having an inconveniently high input sensitivity.
Third is a derivate of the amplifier found in the RCA tube manual based around EF184 pentodes.
There are two power supplies. The main one for all the high voltage and filaments.
The auxiliary power supply for negative bias and regulators for negative CCS voltage and positive SF drain voltage. Because my power transformers don't have a tap for negative bias, an auxiliary PSU occurred to me as the most efficient way to do this job.
Lastly there is the board for the power tubes. I'm uncertain if I'll use it as there will be a lot of heat from the tubes and wiring can easily be done p-to-p.
Feel free to make suggestions, 'shoot' at my plans, etc.
Here's what I've got so far:
-2 pcs. 300,275,250-0-250,275,300 @ 250mA and 6.3V @ 5A power transformers;
-2 pcs. Lundahl LL1663-pp 5k to 8 Ohm.
After reading a lot of posts by SY, Tubelab and Gingertube about Source followers right in front of the power tubes and their positive effects on several areas, there will be SF's in all of the following designs.
All designs are PCB based, but build in building blocks. This way I can easily swap boards to compare and listen to the different designs whilst only having to solder few wires. I intend to order all boards to be able to do this.
I've tried to implement a standard way of working when laying out the PCB's: some sort of star ground, keeping low level traces away from high current ones, keeping leads/traces short. As I'm pretty new to designing PCB's for tube amps, I'm fairly certain that there are some improvements to be made. Please feel free to make suggestions.
Let's have a look at the designs. Let me first say there is nothing new under the sun here for most part.
First up is a ST-70 lookalike with a ECF80/6BL8 (cheap!) and SF's.
Second is a Mullard 5-20/Claus Byrith 4-30 variant. O. Schade feedback and a CCS for the phase splitter are added, because I tend to like the sound of those circuits. Triode connected EF86/EF184 (components should be adjusted) and 12AU7 phase splitter, thus moderate levels of global negative feedback can be employed without having an inconveniently high input sensitivity.
Third is a derivate of the amplifier found in the RCA tube manual based around EF184 pentodes.
There are two power supplies. The main one for all the high voltage and filaments.
The auxiliary power supply for negative bias and regulators for negative CCS voltage and positive SF drain voltage. Because my power transformers don't have a tap for negative bias, an auxiliary PSU occurred to me as the most efficient way to do this job.
Lastly there is the board for the power tubes. I'm uncertain if I'll use it as there will be a lot of heat from the tubes and wiring can easily be done p-to-p.
Feel free to make suggestions, 'shoot' at my plans, etc.
