Unorthodox 2x18 slot loaded PA sub
- By petterhaus
- Subwoofers
- 52 Replies
HI Everyone
I'm Ale from Italy
My english is anything but perfect.
This is my second audio project and I know this is a strange way to do a sub.
I decided to build a sub for my coaxial synergy PA tops built in this thread with the help of many diyaudio guys
https://www.diyaudio.com/community/threads/2x12-and-1-4-coax-cd-synergy.373100/
My main limitation is dimension: 970x750x550mm ( my car trunk dimensions).
My goals are:
1- high spl that can match the tops (105-ish db/1m and about 3kw each)
2- not very low extension needed because I will use only for live rock music so from 45-50hz to 100HZ.
3-possibilty to transport and assemble secondary flare for bigger venues.
I absorbed some ppsl design principles reading a good part of the big ppsl enclosures thread here even if my design is push push.
Usually the plenum depth need to be the smallest possible but with my data I can lower the highest peak down to 100hz using deeper plenum.
With 18ds115-8 I can use little box volume.
The driver chambers are separated.
The triangular BR ports are 440cm2 total (but I can modify easily) with 50m/s velocity at 6800w.
I want to create guides in the wood for the ports to shift it inside and outside and tune differently when I use 2 flare or not.
The secondary flare can accomodate the sub box for compact transportation.
Now i would decide which position is better for left br port. (last picture).
Do you see any problems in this design??
I really appreciate you opinion and suggestions!!!!
Thank you very much
Ale
I'm Ale from Italy
My english is anything but perfect.
This is my second audio project and I know this is a strange way to do a sub.
I decided to build a sub for my coaxial synergy PA tops built in this thread with the help of many diyaudio guys
https://www.diyaudio.com/community/threads/2x12-and-1-4-coax-cd-synergy.373100/
My main limitation is dimension: 970x750x550mm ( my car trunk dimensions).
My goals are:
1- high spl that can match the tops (105-ish db/1m and about 3kw each)
2- not very low extension needed because I will use only for live rock music so from 45-50hz to 100HZ.
3-possibilty to transport and assemble secondary flare for bigger venues.
I absorbed some ppsl design principles reading a good part of the big ppsl enclosures thread here even if my design is push push.
Usually the plenum depth need to be the smallest possible but with my data I can lower the highest peak down to 100hz using deeper plenum.
With 18ds115-8 I can use little box volume.
The driver chambers are separated.
The triangular BR ports are 440cm2 total (but I can modify easily) with 50m/s velocity at 6800w.
I want to create guides in the wood for the ports to shift it inside and outside and tune differently when I use 2 flare or not.
The secondary flare can accomodate the sub box for compact transportation.
Now i would decide which position is better for left br port. (last picture).
Do you see any problems in this design??
I really appreciate you opinion and suggestions!!!!
Thank you very much
Ale
Creek Audio T50 Tuner: Help with disabling RDS from printing on display.
- By gghodg
- Analogue Source
- 5 Replies
Attachments
White dot negative or positive
- By mmaghakian
- Electronic Design
- 18 Replies
I am working on two Audiosource AMP TWO amps and the board marking seem wrong
all the positive leads are marked with a white dot, I thought that meant negative. am I wrong ?
check out all three blue caps in the picture
all the positive leads are marked with a white dot, I thought that meant negative. am I wrong ?
check out all three blue caps in the picture
Purpose of C12 and C13?
- By MagnusBack
- Solid State
- 2 Replies
Wondering what the purpose/function of C12 and C13 is in this schematic?
I'm assuming C13 is added because C12 was less than ideal?
(It's from a Sansui AU-717 driver board).
Anybody who can explain?
I'm assuming C13 is added because C12 was less than ideal?
(It's from a Sansui AU-717 driver board).
Anybody who can explain?
Download PSUD
- By WntrMute2
- Power Supplies
- 6 Replies
I purchased a new Windows 11 laptop and for the life of me cannot figure out where to download PSUD2. I end up on this screen but do not see a download option. Any help would be appreciated.
Looking for Neurochrome power supply boards...
- By dBe
- Solid State
- 10 Replies
I received an amplifier masterfully built by Poseidon's Voice only to be destroyed by USPS. I am in need of a pair of these bare boards. I hope some of you are like me and have parts in the "someday" box.
let me know...
let me know...
For Sale CSS SDX12 XBL2 12" Subwoofer
- By gregulator
- Swap Meet
- 2 Replies
Highly regarded subwoofer driver. Very lightly used, as I decided to go with a higher-sensitivity driver instead. I no longer have the box.
(stock photo)
Local pickup in the San Francisco Bay Area preferred.
Details here: https://www.parts-express.com/CSS-SDX12-XBL2-12-Subwoofer-290-3006?quantity=1
Asking $210 which is over half off list price.
(stock photo)
Local pickup in the San Francisco Bay Area preferred.
Details here: https://www.parts-express.com/CSS-SDX12-XBL2-12-Subwoofer-290-3006?quantity=1
Asking $210 which is over half off list price.
Lower gain Tubelab SSE build
I'm planning on building a Tubelab SSE and am currently in the research phase. In addition to studying the theory behind its design and operation, I've also put together a SPICE model (ngspice to be precise), so that I can study the circuit with fewer possibility of electric shock. (Well, I'm running the simulation on a desktop computer, so there's still some possibility.)
After familiarizing myself with the basics, I though that, since I'm planning to use the amplifier with a DAC that outputs a 2VRMS signal, which seems to be way too high for the "default" 12AT7/EL34 configuration, perhaps it might be worth looking into whether a lower gain build would be preferable. At the very least, it might let me avoid using an attenuation network between the DAC and the SSE, without worrying about overdriving the latter.
In looking into this I've used the simulator (with whatever models I could find) and I'd like to double-check, some of my findings with more experienced folks. So here goes:
1. My circuit is attached below. As shown the B+ voltage comes from the V0 voltage source for convenience and the power supply section is not used. Results are similar when using it, apart form needing to simulate a bit longer to wait for the B+ voltage to stabilize. I'm getting "reasonable" results with it, apart from being able to get on the order of 5W of output at 1% THD from an input of about 1V p-p at 1kHz. This seems a bit low given the results posted by George on the simulations page of the SSE's documentation and also measurements from existing builds. (The output transformer has an inductance ratio that should yield a 5 kOhm impedance from the 8 Ohm load.) I understand that the simulation disregards some sources of THD (e.g. the output transformer), but I wonder if that is that the only issue, or if perhaps something is more seriously wrong with the simulation itself.
2. Assuming the simulation is more or less ok, I find that removing one or both of the bias resistor bypass capacitors, tends to yield lower gain at lower THD. Removing both C10 and C12 for instance, I seem to be able to achieve the same 5W of output as before at about 0.5%THD from an input of about 2V p-p. In both cases, the distortion is predominately 2nd harmonic with some lower 3rd and 4th harmonic components. I understand this is because the absence of bypassing effectively constitutes local NFB. Do these results seem reasonable? Is there any reason to include the bypass caps, even if the increased gain is not required?
3. In trying to reduce gain even more, I've looked into substituting the driver tube with a lower gain part. Initially I've thought about using the 12AV7, but since this seems to be relatively rare, I turned to the 12AY7. Changing R13 to 1K to get about 3 ma of cathode current and R10 to 910 for about 3V of bias, I again get about 5W of output at about 0.5% THD, but now at 3.6V p-p. The driver tube is now being driven hard and the distortion measured at its output is much higher than before, at about 1% THD, but it's almost entirely 2nd harmonic and seem to partially cancel at the output stage. Does that make sense? Is there any reason not to use the 12AY7 then? I figure, apart from needing less attenuation after the DAC, the THD+N figure should be better, since less noise will be amplified.
4. I've found some NOS Russian (or, rather, Soviet) parts locally at pretty good prices, so I thought I might look into the 6N1P-EV, or the 6N23P-EV, which seem to be well regarded. I also found a matched pair of NOS 6P3S-E tubes at the same source, again pretty cheaply and I thought I'd try that too. With a 6N1P, with associated current and biasing changes and a 6L6GC model substituting for the 6P3S-E (which I know is not the same) I could get about 6W at 0.4% THD from a 5.2V p-p source, which is close to the 2VRMS target. I then found out that the filament pins of the 6N1P are not compatible with the 12AT7 used by the SSE. Can I use an adapter to deal with this? I see some "12AX7 to 6N2" adapters; will these work? If so, is there some reason no to use the 6N1* and/or 6P3S tubes?
Thanks to everyone who's read so far; I know it was a lot and thanks in advance for any comments.
After familiarizing myself with the basics, I though that, since I'm planning to use the amplifier with a DAC that outputs a 2VRMS signal, which seems to be way too high for the "default" 12AT7/EL34 configuration, perhaps it might be worth looking into whether a lower gain build would be preferable. At the very least, it might let me avoid using an attenuation network between the DAC and the SSE, without worrying about overdriving the latter.
In looking into this I've used the simulator (with whatever models I could find) and I'd like to double-check, some of my findings with more experienced folks. So here goes:
1. My circuit is attached below. As shown the B+ voltage comes from the V0 voltage source for convenience and the power supply section is not used. Results are similar when using it, apart form needing to simulate a bit longer to wait for the B+ voltage to stabilize. I'm getting "reasonable" results with it, apart from being able to get on the order of 5W of output at 1% THD from an input of about 1V p-p at 1kHz. This seems a bit low given the results posted by George on the simulations page of the SSE's documentation and also measurements from existing builds. (The output transformer has an inductance ratio that should yield a 5 kOhm impedance from the 8 Ohm load.) I understand that the simulation disregards some sources of THD (e.g. the output transformer), but I wonder if that is that the only issue, or if perhaps something is more seriously wrong with the simulation itself.
2. Assuming the simulation is more or less ok, I find that removing one or both of the bias resistor bypass capacitors, tends to yield lower gain at lower THD. Removing both C10 and C12 for instance, I seem to be able to achieve the same 5W of output as before at about 0.5%THD from an input of about 2V p-p. In both cases, the distortion is predominately 2nd harmonic with some lower 3rd and 4th harmonic components. I understand this is because the absence of bypassing effectively constitutes local NFB. Do these results seem reasonable? Is there any reason to include the bypass caps, even if the increased gain is not required?
3. In trying to reduce gain even more, I've looked into substituting the driver tube with a lower gain part. Initially I've thought about using the 12AV7, but since this seems to be relatively rare, I turned to the 12AY7. Changing R13 to 1K to get about 3 ma of cathode current and R10 to 910 for about 3V of bias, I again get about 5W of output at about 0.5% THD, but now at 3.6V p-p. The driver tube is now being driven hard and the distortion measured at its output is much higher than before, at about 1% THD, but it's almost entirely 2nd harmonic and seem to partially cancel at the output stage. Does that make sense? Is there any reason not to use the 12AY7 then? I figure, apart from needing less attenuation after the DAC, the THD+N figure should be better, since less noise will be amplified.
4. I've found some NOS Russian (or, rather, Soviet) parts locally at pretty good prices, so I thought I might look into the 6N1P-EV, or the 6N23P-EV, which seem to be well regarded. I also found a matched pair of NOS 6P3S-E tubes at the same source, again pretty cheaply and I thought I'd try that too. With a 6N1P, with associated current and biasing changes and a 6L6GC model substituting for the 6P3S-E (which I know is not the same) I could get about 6W at 0.4% THD from a 5.2V p-p source, which is close to the 2VRMS target. I then found out that the filament pins of the 6N1P are not compatible with the 12AT7 used by the SSE. Can I use an adapter to deal with this? I see some "12AX7 to 6N2" adapters; will these work? If so, is there some reason no to use the 6N1* and/or 6P3S tubes?
Thanks to everyone who's read so far; I know it was a lot and thanks in advance for any comments.
Aikido "oTTo" All jFET Phono RIAA Pre-Amplifier - Schematic wanted
- Analogue Source
- 8 Replies
Attachments
Buzz kill
- By Pilipdilip
- Solid State
- 4 Replies
Hello, I have just rebuilt an old Playmaster Electronics Australia Mosfet amp (circa 2002 or so). Firstly I am looking for a circuit diagram, It has 6 power mosfets each channel and from memory it's 200watts RMS into 8 ohms. However I found some old circuits using 4 power mosfets that also claims to be 200 watt RMS and these have similar topography but not exactly the same . They all run on +- 70vDC rails. Anyway it basically works perfectly except when I join the minus of the inputs at any point I get a very low transformer buzz from both speakers. You have to stick your ear right to the speaker to hear it. I am on a mission to make it perfectly quiet! Chassis is grounded to mains, centre tap of both transformers goes separately to the PCB ground (0v) tracks (that track also connects directly the centres of an array of 2 x 2 x 6800uf caps per side), then single ground (0v) wires from those tracks to the centre bolts of each of the bridge rectifiers (chassis). One diagram I have has those grounds connected to chassis via a 0.1uf cap?? The signal input minus passes through a 10 ohm resistor to ground (0v) and as I mentioned above any joining at any point of that left and right signal minus creates the exact same level of buzz. Secondly the bias: currently at idle I have set about 12mv across the .22 ohm FET source resistors , though some of them are showing about half that. So I figure that is about 50ma per power FET except the ones that are about 7mv. Just curious. It is driving a pair of 1988 vintage AE1's sounds totally awesome.
OPA1612 from Aliexpress, no counterfeit but why so cheap?
- By gamerpaddy
- Parts
- 54 Replies
After working with some OPA1612 on my recent Topping PA5 D01 Module replacement project (at ASR),
a friend sent me a few OPA1612 opamps he ordered when they were in stock since i couldnt get them anywhere.
alongside with some aliexpress el`cheapos for like 2 buck a piece instead of 7..8 bucks for a genuine part.
i expected them to put some cheap crap in there, so i didnt wanna use them.
but was curious whats in there, so i opened one up.. surely they have put a tl072 or ne5532 in and relabeled it..
turns out, after extracting the Silicon Die, they are genuine.
Do they not meet the manufacturers specifications and are rejects or something else?
nothing my budget equipment can measure, but they worked fine, didnt have any louder hiss than the original parts and didnt oscillate or anything, even power draw was about the same.
this was from two different sellers at two difference price points on aliexpress, it doesnt mean everyone on there sells genuine parts.
i now ordered some more for like 80 cents a piece to see, whats going on with them. gotta wail til they arrive.
hearing them vs. the genuine part thats in spec, isnt conclusive either, its differences are so minor, my ears cant pick them up.
Original (mouser):
from a device that used them (actually the topping i mentioned above, extracted from the module)
, the damage to the right might be due to my extraction methods.. this chip is barely a millimeter in height and im not using any chemicals.
Aliexpress seller 1
Seller 2
(zoomed out, not to scale anymore)
for comparison, a genuine OPA1656
Ti NE5532
TL072
a friend sent me a few OPA1612 opamps he ordered when they were in stock since i couldnt get them anywhere.
alongside with some aliexpress el`cheapos for like 2 buck a piece instead of 7..8 bucks for a genuine part.
i expected them to put some cheap crap in there, so i didnt wanna use them.
but was curious whats in there, so i opened one up.. surely they have put a tl072 or ne5532 in and relabeled it..
turns out, after extracting the Silicon Die, they are genuine.
Do they not meet the manufacturers specifications and are rejects or something else?
nothing my budget equipment can measure, but they worked fine, didnt have any louder hiss than the original parts and didnt oscillate or anything, even power draw was about the same.
this was from two different sellers at two difference price points on aliexpress, it doesnt mean everyone on there sells genuine parts.
i now ordered some more for like 80 cents a piece to see, whats going on with them. gotta wail til they arrive.
hearing them vs. the genuine part thats in spec, isnt conclusive either, its differences are so minor, my ears cant pick them up.
Original (mouser):
from a device that used them (actually the topping i mentioned above, extracted from the module)
, the damage to the right might be due to my extraction methods.. this chip is barely a millimeter in height and im not using any chemicals.
Aliexpress seller 1
Seller 2
(zoomed out, not to scale anymore)
for comparison, a genuine OPA1656
Ti NE5532
TL072
2SA1837+2SC4793 (5pairs)
Here i have for sale NOS 2SA1837+2SC4793 5 pairs (total 10devices).
Price is €20,00 (for 5 pair) + Shipping Cost and it is selling as 5pair only.
Price is €20,00 (for 5 pair) + Shipping Cost and it is selling as 5pair only.
Aleph P1.7 assembled board
Aleph p1.7 completed board for sale.
Solid brass bar keeps all mosfets equally hot, relays are itt, gain fets are harris devices, attenuator section uses sfernice resistors and some nos siemens 0.1% resistors. In/out capacitors are roederstein mkc, capacitance is smaller than advices 10uf, but if load is not tough its alright.
Ps photos are from construction, bad soldering on adc chip is corrected.
Asking 230 euro.
Board size 20x30 cm
Solid brass bar keeps all mosfets equally hot, relays are itt, gain fets are harris devices, attenuator section uses sfernice resistors and some nos siemens 0.1% resistors. In/out capacitors are roederstein mkc, capacitance is smaller than advices 10uf, but if load is not tough its alright.
Ps photos are from construction, bad soldering on adc chip is corrected.
Asking 230 euro.
Board size 20x30 cm
For Sale MODUS AMP - PCB
Here for sale i have MODUS amplifier, 2pcs RED PCB, copper thickness 70um (2oz).
It is nice amplifier using cascoded IPS + cascoded VAS. Have high slew rate of 62V/us and uses bipolars at output. Schematic will be send to buyer address.
Price is €25,00 + Shipping Cost for 2PCB
It is nice amplifier using cascoded IPS + cascoded VAS. Have high slew rate of 62V/us and uses bipolars at output. Schematic will be send to buyer address.
Price is €25,00 + Shipping Cost for 2PCB
FLATBT PREAMP - PCB
Here i have for sale FLATBT PREAMP PCB that is high quality preamp, using RED solder mask and 70um copper thickness.
It uses cascoded IPS + cascoded VAS + bipolar TO126 output devices. Schematic will be sent to buyer address.
Price for 2pcb is €20,00 + Shipping Cost
It uses cascoded IPS + cascoded VAS + bipolar TO126 output devices. Schematic will be sent to buyer address.
Price for 2pcb is €20,00 + Shipping Cost
Marantz Superscope CD 330 can't record on left channel
- By lorso
- Analogue Source
- 6 Replies
Attachments
For Sale XRK TPA 3255 Ref
- By iplayforme
- Swap Meet
- 7 Replies
I don't know what Iwas thinking. I'll never get these small SMD parts on. I'll end up throwing a fit. Selling the amp and buffer boards as well as the Mouser supplied parts shown in the attached invoice. As I remember it was 99% available/complete, the BOM that is. I also looked for the VR that was totally unavailable. It was Ebay but really did seem kosher. There is a mystery part I purchased outside of Mouser that I can't ID. You'll be 99.5% there. Id like to get $150 shipped.
12v to dual rail converter
- By MJC147
- Electronic Design
- 9 Replies
Hi, im having a go at building a dc-dc converter, that will take 12v and output +55v, 0v and -55v.
This is the circuit i am using, with a hand wound toroid transformer:
Unfortunately, im not reading any voltage on the 50-0-50 outputs, however using a basic oscilloscope with channel 1 attached to point 1, and channel 2 attached to point 2, with oscilloscope ground to point G, i believe that the oscillation side of the circuit is working ok (this reading was taken without the transformer attached, so just testing the oscillating circuit)
Im not quite sure why channel 1 is not swinging as much as channel 2. Both read as having a frequency of 35khz.
I may have wound my transformer wrong, anyone know how to wind a transformer like this? I doubt i can purchase a specific one for this.
Any ideas appreciated, better circuits etc.
This is the circuit i am using, with a hand wound toroid transformer:
Unfortunately, im not reading any voltage on the 50-0-50 outputs, however using a basic oscilloscope with channel 1 attached to point 1, and channel 2 attached to point 2, with oscilloscope ground to point G, i believe that the oscillation side of the circuit is working ok (this reading was taken without the transformer attached, so just testing the oscillating circuit)
Im not quite sure why channel 1 is not swinging as much as channel 2. Both read as having a frequency of 35khz.
I may have wound my transformer wrong, anyone know how to wind a transformer like this? I doubt i can purchase a specific one for this.
Any ideas appreciated, better circuits etc.
WinISD safe to download?
- Software Tools
- 32 Replies
I want to start playing around with speaker design. I know that WinISD is very popular and FREE. When I went to www.linearteam.org and Google Chrome gave me this warning:
When I hit 'Advanced', it gave me this warning:
Who is *.asiakkat?
Is there a safe place to get this software?
When I hit 'Advanced', it gave me this warning:
Who is *.asiakkat?
Is there a safe place to get this software?
Neurochrome HP-22: A high-performance DIY headphone amp for less than $100
- By tomchr
- Vendor's Bazaar
- 122 Replies
Attachments
-
HP-22_Proto_wPuck.jpg -
HP-22_Proto_Front.jpg -
HP-22_Proto_Rear.jpg -
HP-22_Proto_wTIbox.jpg -
HP-22_Proto_PCB.jpg -
HP-22_ THD+N vs Output Power (1 kHz, 300 ohm, 20 kHz BW).png -
HP-22_ THD+N vs Frequency (100 mW, 300 ohm, 60 kHz BW).png -
HP-22_ Multi-Tone IMD (AP 32-tone, 100 mW, 300 ohm).png -
HP-22_ Residual Hum & Noise.png
Concrete Fidelity. My first DIY speaker build; cast from concrete
- By samthebaam
- Full Range
- 9 Replies
I recently built some desktop speakers from concrete, and I am trying to understand my measurements.
I am quite happy with the overall sound, but they are definitely missing some base.
I am using a Dayton Audio DS135-8 woofer with a Peerless Tymphany BC25SC08-04 tweeter and crossed them at 1700hz in a sealed 3l enclosure. (Datasheets attached)
Below my far field on axis response measured at 1m
Here my near field measured response of the driver
How do I further smoothen the response and extend the bass? Do I simply need a sub?
This is my first DIY speaker so, excuse if there are any obvious omissions or mistakes.
I am quite happy with the overall sound, but they are definitely missing some base.
I am using a Dayton Audio DS135-8 woofer with a Peerless Tymphany BC25SC08-04 tweeter and crossed them at 1700hz in a sealed 3l enclosure. (Datasheets attached)
Below my far field on axis response measured at 1m
Here my near field measured response of the driver
How do I further smoothen the response and extend the bass? Do I simply need a sub?
This is my first DIY speaker so, excuse if there are any obvious omissions or mistakes.
Beast Mini
- By Jacruzer787
- Pass Labs
- 15 Replies
So I am listening to a podcast with pa that dropped 11 days ago. (Link) Apparently pa is working on a J113 version of the mythical beast. 256 Jfets. 
Looks like the worldwide stock of J113 might drop a bit! If this is being discussed elsewhere, let me know!
Hey pa, if you need anyone for prototyping and testing, ill take the bullet.
Best,
Jose
Looks like the worldwide stock of J113 might drop a bit! If this is being discussed elsewhere, let me know!Hey pa, if you need anyone for prototyping and testing, ill take the bullet.
Best,
Jose
Help wiring these German transformers
- By MusicWorks
- Tubes / Valves
- 32 Replies
I purchased these German line output transformers some time ago, they are marked 019.1 and come from a broadcast mixer comissioned by the RFZ (the East-Germany BBC. Well known for their lovely preamps, I purchased these for some pres I have from these old mixers.
I assume these are matching transformers, but Its impossible to find a diagram and I mysef have never wired/tested a transformer.
Any help in wiring this would be much appreciated! It would go from the preamps unbalanced output into the trafo and out to the XLR mounted on the chassis.
Thanks a bunch!
-- MusicWorks
Crossover help needed - too fast phase shift around 3.7-4-7Khz
- By db-acoustics
- Multi-Way
- 41 Replies
Attachments
I blocked my Floyd Rose Tremolo
- By jjasniew
- Instruments and Amps
- 3 Replies
Frankly I couldnt stand it anymore. Breathe on it and the pitch modulates, as in just the finger effort to turn one of the little trim screws changes the pitch as much. Stuck with mushy light gauge strings, pulling against 3 heavy springs, the stupid locking nut that doesnt, the bar that isnt a machine tolerance fit in the socket, wiggles no matter how hard you tighten the cap - no more - "I'm so done with you"!
Glad to read on line you can just do this. One day I'll get a solid tail guitar; this'll have to do till then. Looking at candidates I think "it has springs... nope!"
Glad to read on line you can just do this. One day I'll get a solid tail guitar; this'll have to do till then. Looking at candidates I think "it has springs... nope!"
