Hi dude, I need a piece of advice:

I would like to create an audio channel strip (preamp-equalizer-compressor) all made by me and I would like to be able to reverse the order of the components (eq and comp, the preamp must always be at the beginning of the chain) can I do it with a switch? (pos1=EQ —> COMP pos2=COMP —> EQ) and if it’s not possible with a switch how can I do it?
I was thinking about relays but i don’t know how to connect them, do you may have any schematic?
Instead I would like to avoid digital switches or mosfets.

I remind you that the signals are balanced so in addition to the ground there is a positive and a negative signal in input and output from eq and comp.

Thanks a lot in advance!🙂

Massimiliano

I've got a pair of rola 12px speakers.

All I know is they are full range and rated at about 20W.
Seller claims that they require a 12 cubic foot capacity cabinet, but that feels awfully huge!

Also wanting to know if they require vented or sealed cabinets?

I'm assuming that I can get the cabinet size right down if I stuff them full of dacron?

Either way they are a nice 12 inch speaker that should go well with a tube amp as they are 5 ohms impedeance.

Hello everyone,
I was wondering if anyone had ever done a clone of the Energy 22 Reference Connoisseur speakers. I have a pair of the Reference Pro and still like the sound that comes from them. I am recently retired carpenter and looking for a project to keep myself busy so thought this might be something to try.
Any thoughts would be welcome pro or con.
Thanks and happy tunes.

what would you do with this 1000w beast? calling power amp experts

I bought this over the Christmas period. I could not find any info, so bought blind! It was not a lot of money. I liked the size of the transformer! and that is was passively cooled. It uses 3x2 Motorola MJ15003/4 and a pair of MJ15001/2 per channel. It is rated at 250w into 8 x 4 channels. Made by a Swedish company called Amtech. The only thing I could find was they had made what seemed to be a high quality mixing desk, so I sort of hoped this may be a high quality amp for studio use.

I have since tracked down a schematic and circuit diagram, attached.

My intended use is to drive via a dsp active crossover (dbx venu360) a pair of 8" bass units on my hybrid Innersound Isis ELS, and a pair of Linkwitz open baffle subs, in a domestic hifi environment.

Any thoughts if this is with bothering with, I am worried by its PA spec, maybe someone could suggest swapping out parts or boards to make a better unit? ideas?

World’s Best Speakers! - YouTube

This guy employs engineering and scientific methods in creating what he says are the world's best speakers. These might make good PA speakers for permanent installation. I think these speakers have the potential to provide accurate sound and superb coverage in most spaces and they are cheap to build.

:eek:Trigger Warning: Some of the content in the video may trigger cognitive dissonance and hostility in sensitive individuals. Most of you will enjoy it. 🙂

Give me your thoughts on the video.

Thank you.\

Dear people,

Because a picture is worth a thousand words I have attached a visual representation of my questions below.

In a mock up amp I have made mini star grounds per stage which connects directly to a buss bar as in option 1 on the picture. Amp is very quiet hum wise.

Now for layout reasons I am considering connecting the mini star grounds to the buss bar through a short wire, as in option 2 on the picture.
Would this be detrimental because the local grounds now share a single wire before connecting to the bus bar? Would the connecting wire need to be thick?

For saving chassis space I am also considering option 3. Yes, in this option chassis is used as a ground connector, but the grounds are ordered in mini stars before connecting to chassis and the chassis grounds are ordered in a straight line. Chassis is used as the buss bar.
What would be the downside of this option?
Could a possible problem be that the fields of the power transformer interfere with the chassis ground reference?

Now I finally see I was doing it completely wrong! All my cables are passive.
Check this out:
Tube powered active cable interconnect 1m | eBay

Radical Tweeter Capacitor...

This thread was split off from here: The "Elsinore Project" Thread - Page 46 - diyAudio

LET'S GET RADICAL - THE RADICAL TWEETER CAPACITOR

This is the beauty of DIY, please read the following as it is an optional add-on to the Elsinore design.

I have stated previously that I reckon the series capacitor to the Tweeter, the so-called High-Pass filter capacitor, is the single most critical crossover component (not that the others remain unimportant). There are some fairly unknown (generally speaking) reasons behind this and here is the first time I have actually stated more precisely the reasons for it.

Research has shown that THIS capacitor is prone to nonlinear distortions and particularly of the IMD (intermodulation distortion) kind. When capacitors directly in the signal path sees an AC signal that traverses zero Volt DC - and that is really what AC does - the distortion is primarily odd order (bad kind), but if the same capacitor is biased DC wise, then it becomes more even order (sweet kind). We know that if we have to choose between those we'd take the latter any day.

What this means is that capacitors directly in the signal path will sound better in most amplifer circuits where it is used to block DC, such as in tube amplifiers, BUT... when it comes to speakers, there is no DC and hence in speakers the very same capacitor will potentially sound worse.

Since we don't want DC in our speakers, we really are stuck with a bad situation.

Or are we?

Take a look at this:



BEFORE: Shows the current crossover.

AFTER: Shows the same crossover in-so-far that the series capacitor has the same 4.7uF value when the series-parallel configuration is taken into account. Then the crossover function is exactly as before.

So what is going on here. Simply the 9V battery (should be new alkaline and about 9.5V) available at just about any corner shop, biases the coupling from the centre outwards. Without any signal to the Tweeter, both sets of caps see the same 9.5V across it. This is because it is 0 Volt DC on the other side of both caps.

When an actual AC signal (music) comes along, when positive, the voltage will swing upwards above the 9.5V and there will be no celing and when it goes negative, it will eat into the 9.5V of the battery. So the available voltage swing where DC remains across both side (caps) is +infinite/-9.5V - or put is another way, it is able to swing 6.7V RMS before the bias (not the signal) clips on the negative side.

Now can you guys understand why I like and recommend external crossovers (easier access)?

PARTS: You will need to quadruple the number of your 4.7uF caps, although you could also use 10uF - but the result will be 5uF instead of 4.7uF, so you might perceive a little more energy in the presence region. The 100K resistor should be a good quality 1 Watt type. The battery should be a long life alkaline type. The resistor limits current to 100uA pretty much all the type. A couple of battery snaps/wires that clips onto the batttery.

BTW, you could double up on the battery and get an effective 19V DC Bias. Whether that would be audible probably depends how loud you like music? Haven't tried, only 9.5V.

How long will the battery last? Almost certainly for years and close to its shelf life. Just check its voltage from time to time.

I am not going to tell you in advance about any sonic gains. I don't want to telegraph your reactions and I want them to be fresh and in your own words.

SO WHO WILL BE THE FIRST CAB OFF THE RANK?

Joe R.

so i haven't built anything in a long while last thing i built was a slightly modded pair of zaph zrt 2.5's several years back, life got busy and hobbies went on hold.

Anyway sob story over. I have had several drivers kicking around that i picked up on various sales that i intended using for projects that i never got round to. I'm thinking rather than just sell them i could probably knock out a half decent pair of garage/party speakers. I'm thinking largish cabinets somewhat vintage jbl, vega looks 3 way.

i started working on a crossover but i cant get it to play nice across the whole range.

not sure if anyone would mind having a crack at helping me find a half decent starting point, i have built several successful 2 way designs but this 3 way is kicking my butt.


I'm not aiming for perfection here just a good all rounder for knocking the tunes out in the garage and getting the wife off my back by freeing up some closet space.

I have a feeling the xt25bg60's wont be ideal in an off axis listening environment like a garage but i don't really want to throw a bunch of money into different drivers.

drivers i have

2x Peerless NE265W-08 10inch

2x Peerless TPY05W08O0088 5-1/4inch

2x Peerless XT25BG60-04 1" Dual Ring Radiator Tweeter


i also have a pair of focal/jmlab t98ti tweeters that may work but i can't find any data on them.



i have been using Jeff Bagby's passive crossover designer but i cant seem to get it to save the data out properly to share but i have attached the spec sheets, zma and frd files i made from the spec sheets. i dropped it all in my google drive including the xls it just wont load up properly on another computer for some reason or other.


classic 3 way - Google Drive

Can anyone tell me how the anti-vibration circuit is configured on Rega's 24V motors. My understanding is that it is mostly a typical arrangement with a phasing capacitor, but there is also a trimmer to adjust the phase angle. Is this a variable resistor to adjust the voltage, or a variable capacitor to adjust the capacitance value and how is it supposed to be wired in respect to the coils?

I'm resurrecting an RP3 that fell victim to a PSU failure and the PCB sustained some damage, including a couple of missing traces and damaged markings on components. Any help greatly appreciated.

Hello!
Anyone has successfully built this amplifier? Would you share your thoughts and experience?

monobloc-se-32-cfb-2012version

How it sounds??

Thanks in advance!!

just wanted to share my experience with the 1629 magic eye tube. Many years ago I fell upon Steve Bench's site -now can be found here- where he mentions his experience and measurements of the 1629.
Out of curiosity I ordered then a couple of tubes but after that I got busy with other projects and obligations and forgot about it.
Last week as was browsing my archive I remembered about it and decided to give it a try. I made a quick and dirty assembly on a small piece of plywood and went on to take some measurements. In this grounded cathode configuration the output impedance is very high, at about 13.4k, and so it it is unsuitable for driving any power amp with low input impedance. So I went on and added an ECC82 cathode follower, DC coupled. HV is at 305V regulated with LR83N, one per channel. Heater supply is DC elevated by 45V. Maximum output is a healthy 44Vrms before clipping.
The circuit is free of hum despite being so close to power xformer, however the 1629 has somewhat high thermal noise so I put the volume control at the output and now is totally silent even at high listening levels.
Listening experience was a very pleasant surprise and hence this post 🙂 Steve measured a predominant 2nd harmonic and this shows indeed in practice. The preamp is really sweet sounding but not to the expense of detail, I could say the exact opposite. It plays so nice that I am really tempted to built a proper chassis for it, despite the fact that I already have another three 🙄
And by the way an added advantage with this is that you have a pair of beautiful eyes to look at while enjoying your music 😀

Hi Friends,

Is there any physical requirement forcing makers to make the tubes so huge? Can they be miniaturized? Now adays there are mechanical parts inside microchips (gyros, accelerometers....) so why not tubes at the size of a 2000uF capacitor for example?

Does anyone knows?

ADAM S5VAmk2 Crossover Board Repair

Hi - I'm looking for any advice, or possibly a schematic diagram for a 4-channel filter board (crossover) from one of my ADAM-S5VAmk2 Studio monitors. Any help would be greatly appreciated!

Hi everyone, i started this thread because i never heard a lm1875 amp and want to know more about it. I have plenty of lm3886 and i'm very impressed by its sonic qualities. Very nice sounding and super low end reproduction but i don't know about 1875. As you know this one is the ultimate warrior of 5 pin chipamps (UTC 2030/50 hard to find here and globally) and that's why i want to store couple of them for future diy projects. It's not about power or vanishing THD figures, just think about a good 20watt amplifier. How it sounds? 🙂 Btw i have made 2030 and 2050 in past and liked both.
Tda2030A was good at low end and i found 2050 little bit bright but strong

Hello, me again...

I‘m in the pre-final stage 😇 of my F4 build, connscting stuff.

There will be 1 connection through a ICL to the chassis from the PSU (and the amp-boards connected to the PSU), the connection of the IEC safery earth, and there‘s a last one, the toroidy transformer...

I‘m not sure wether I should connect them all to 1 point only, or wether it is ok to have the star-ground on one end of the chassis, and iec-safety-earth & toroid at the other end?

Or even something else?

Thank you for advices!

hello all,
here is my problem with my old hcca 250r.


The 2 rectifiers on the under side of board where pulling lot s of juice, once they where off voltage was ok. I am wondering the guy who fixed or tried to fix it maybe he did not put them back at the right place. I see they are 2 different rectefiers, here are some pics.


I would love to know wich one goes where.

Thanks guys and sorry for not posting in right place before 😉

Shared album - Bud Man - Google Photos


Shared album - Bud Man - Google Photos


Shared album - Bud Man - Google Photos

Having a garage clear out and found a Turtle Beach Audiotron unit.

Free to anyone that wants it - you just pay for postage at cost.

I think I still have the remote control for it - i'll go looking for it...

UPDATE 1/10/21 BOTH KITS SOLD!


UPDATE 1/9/21: Kit 1 SOLD! Kit 2 AVAILABLE!

Please read carefully.

I have 2 New In Box Spud Kits. Link: The Spud Kit – …hearing is believing

Kit 1: New in Box with an extra set of NOS RCA tubes.

Kit 2: New in Box but does not have have the metal chassis plate. Does have a punch sheet for you to drill you own chassis OR contact Jerry to purchase a steel base.

I am local to NYC and can meet for pick-up. Current cost of kit is $390.

Kit 1: Asking $200 and you pay actual shipping; I'll email weights and dimensions No S&H charges.

Kit 2: Asking $175.


Nick



EDIT ADDED: Shipping is $21.10 USPS Flat Rate. I prefer USPS Money Order (I have excellent feedback on eBay, Audiogon, US Audio Mart and Audio Circle) but I'll take PayPal plus 3%.

Hello, I am building MX50 amp. Already ordered amp modules. Transformer will be 150VA 22-0-22 as recommended and calculated on some forums and it will provide sufficient power for my needs.



Now - it is highly recommended that speaker protection board has independent power supply . Does it mean I need power transformer with more secondary windings or totally separate PS?



Are those protecting board affect sound quality? Is it better to but or make a DIY one?


thank you

Hi All -- I have an Edcor Power Transformer on my tubelab se that has been buzzing, and based on advice in another thread, I removed the end bells, and placed popsicle stick shims between the laminations and the bobbin on the top and bottom.



When I put everything back to together, I no longer have a connection between the laminations and ground, as I did before. I still have it in the OTs, and I still have it on power transformer mounting screws.



Everything works fine (and buzz is gone!) but have I done something dangerous? What are the risks of the laminations not having a path to safety ground. If I touch the transformer to see if it's hot will I get zapped?

I purchased a pair of these kits: PASS-AM V15 Class A by Zerozone.

I have a dc offset at more than 100mV on both of the amps, and I'm not so happy with that.
I would like to be able to adjust that, but I'm not sure where the correct place would be to add a trimmer? Hope somebody can help?
Attached is a schematic I found on the internet and a picture of the boards. I'm not sure the schematic is 100% correct, but it seems to match pretty well regarding number of components and values.

I thought this was a push/pull, but it seems only one of the big transistors are 'drivers' and the other is a current source?

The advertised name refers to mr Pass, but I don't know which amp they cloned in that case?

Suggestions are welcome!

Hello,
I'm hoping for some suggestions for speakers that are particularly suited to playing Jazz. My current plan is to build a pair of Bottlehead Paramounts (300B) or perhaps an offering from Welborne. I currently have a pair of Thiel CS 1.6's mated to a SS amp and CD player. Nothing special yet I was hoping to take better advantage of the Thiels. From what I've seen, it appears the Thiels aren't a very good match for an SET amp. They're spec's: 88db sensitivity, 4 ohm/3 minimum and a minimum amplification of 50 watts. Set's obviously don't match up very well and though P/P is an option I'd rather do an SET. I'm planning on building the amps and just trying them with the Thiels and see what happens. Worth a try at least. I listen in a small room at low to medium spl levels. I'd guess that 95% of what I listen to is jazz. I suspect that setup may not prove suitable for long. So, I've begun looking into potential DIY speaker projects. If you enjoy Jazz, what speakers are you using and what insights can you offer. Details about DIY projects would be greatly appreciated.
Thanks!

Hi there guys,


Got a Focal FPS 4160 laying here, where I'm struggling on for a couple months now.
The amplifier is making a lower amplitude but clear sound at CH2 on the speaker output.


I checked the output of the filter circuit and the sine wave amplitude is excactly the same which is going to the input of the driver board. So, both driver boards (CH1 and CH2) has the same input sine wave amplitude.
The output of the driver board from CH2 has a weaker sine wave amplitude.


I checked and compared all resistors from the driver boards, measured the transistors and diodes, but I could not find a difference in readings between both driver boards.


Does anybody had the same problem? Or somebody knows how to fix this?
Attached are the schematics of CH2 from the driver board input to the speaker output.

Q11, R1, R14, R20, R13 reads OK

Hello,

I am interested in your enclosure with the modification service

Do you provide drawings that I can mark up?

How do I get you the panel cutouts that I need?

Are you able to install pems, studs, etc?

Thanks;
Leo

The Logitech z623 system came to an end when the control pod switches started to not work properly. Tried to fix but nope.......crushed more surface mount components than able to replace.

Sooooo... the subwoofer was more than my listening room could use (at reasonable levels) and there is a bad room resonance around 60hz.

So I removed the sub driver from the cabinet and set about to build a replacement cabinet with new class D amplification.

Progress reports to follow.....

I didn't find info in similar threads and am wondering if there's a source for a crossover schematic. My speaker is 20 years old and I've read various opinions about re-capping.

Any help will be appreciated.

Looking for a Carver M-240 Mobile amplifier in VGC to complete an installation. Any leads or offer are appreciated.

Respectfully,
Carlton

Got a line on one of these.Anybody have any experience with this make/model? Checked everywhere for a manual,nada.Seems to be late 1980's with pretty good specs.

Thanks!

Hi all - a basic question, but one which has confused me a little:

For a Class A single-ended amp, the efficiency is quoted as 25%, however I've read that's for a resistive load and the efficiency with an inductive load is 50%.

Therefore, if sizing a power tranny for a 12w stereo, should I be looking for B+ rating of 12x2x2=48W? Adding, say, 10% for transients taking it to ~55W. I'm sure there's some rule-of-thumb out there.

I don't want to undersize, but as the same time double the iron necessary is, well, unecessary.

Thanks in advance!

Hi all,
I’ve got radio appearing out of the preamp (no tuner attached), when I’m using the phono input. I’m sure this has been mentioned before, but I can’t find reference to it. Has anyone experienced this and solved it.
Tape Monitor is dead quiet and when the tuner I pod selected that’s dead quiet too.
Many thanks in advance
Joe
Ps not Audi, Audio

Hi Folks,


i recently got on the cheap, two of these Sure AB32321 IRS2092 Boards, the ones with 2x125 Watt.

I noticed that is has an BTL/Stereo switch on the Board and on their page, Sure says that the Board is capable of working with bridge tied load,...but they dont mention either with what minimum load impedance nor what wattage the board would produce.
The Manual clearly states that the board should only ran with minimum impedance from 8 ohms in stereo mode, so what should one assume by using btl?



Did anyone got experience with these specific board, or maybe maybe if, some measurements how it behaves with btl in general?
I mean, thing is that there is no such thing as an really "only" 8 ohms speaker got me thinking, that they had to write something but did not want to go full concrete.

Or i am able to only drive "above" 8 ohms speakers with this borad, to be in the clear? 😛


Swany

Guys,

found these and know I will not finish the project.
Asking price 50,- EUR plus shipping. Paypal possible.

Thx.

Having a free moment, I tried to check the amplifier with the oscilloscope. I checked the gain, power and frequency characteristics as far as I can operate the oscilloscope and generator.
I did this using dummy load 4 and 8R. Everything looks ok except for a square signal test at 4R. At an amplitude of 8 Vpp, the triangle and sine are at the clipping limit. The square signal causes a squeak inside, the amplifier and speaker protection turns off the output for a while - then there is silence. There is a sequence of protection operation - on / off. I can't see anything specific on the oscilloscope.
I am asking for help and advice or should I worry about it?

Doing a bit of cleaning I found an old gem: (sorry for the blurry pic)


3xPCM1704, bought years and years ago for a project that never happened...


Anyone has an idea what they could be used for nowadays ?


or if anyone can demonstrate they have the skill to use them I'll send them away for free.
**Edit: I'll keep them for the time beeing**

Answers in the thread please.

@Mods, maybe should have posted in swap ? It's not like I want any payment other than getting
these chips to play music - like they were meant to 😉

Hi All,

I'm not sure if this is expected behavior given the actual DC Offset measured at the speaker terminals is stable at 0-1mV Left and 0-3mV Right, after warming up.
What I can't figure out is why the output from the DC Servo (U1 pin 8) is 50-150mV (it rises over several minutes) on the Left Channel, and (U101 - pin 8) is a steady 3mV on the Right Channel. Which channel is expected behavior? Or is this type of discrepancy expected due to component tolerances?
I've marked all the components I replaced in red (on both channels).
I do not understand how to isolate this issue with all the feedback loops. Am I correct in understanding that the computer on the Input Board is adjusting the dc offset (somehow) according to the value of U1(8) :ANA DC OFFSET?

Some other voltage readings.
C18 (across) - 19 mV
C118 (across) - 43 mV

C2 to ground - 80 mV
C102 to ground - 30 mV

The Idle voltage is equally stable on both channels around 21.5mV.
Any guidance is appreciated.

I'm planning on building two H-frame (sub)woofers - tomorrow😉 - with dayton audio rss390ho-4. I bought the drivers for sealed subs, but dipole might chime in better with my dipole main speakers.

They'll be crossed quite high (80-100hz) and I'm mainly interested in great bass quality, not in lowest sub-bass.

Two opposing schools AFAIK:
- dominant one being high qts & low xmax (alpha 15 et al)
- low qts & high xmax & heavy eq (Linkwitz, 'My open baffle-less speaker journey' etc.)

Since I have power and dsp in the form of Behringer NX3000D, I figure the daytons would work in H frames (c. 17x17x15").

Any thoughts?

Simon

OK so I'm sure I'm not gonna get a lot of love for this but here goes... Does anyone see any eBay tube pre-amp kits that could be easily or somewhat easily modified with cutting tracks ,changing component values and replacing crap ones, ect.... So that it could be used as a basic preamplifier for bass guitar.... Basically a pre-amp to run into a power amp or a straight bass amplifier? If so which one and how would I go about doing so? If anyone has anything similar they have seen or done personally please comment. If anyone has any constructive thoughts please comment.... But if you are just gonna **** on me save your energy. Thanks everyone. Also there is a kit called a single bottle pre-amp kit at DIY tubes. Com and there is a power supply kit also looks very affordable what would I need to do to make that a complete Pre amplifier set up and ready to rock? If you have the energy check it out for me please if not cool.... Thanks Again I am amazed at how many smart people there are on this site. Really makes a guy feel a lot less smart hanging around here lol. OK cheers... -dustin

The chromecast audio from google appears to stream over wifi and has optical out. Anyone planning to get one and integrate to projects ? The digital out is very tempting so I would be able to wifi stream to a separate dac. There doesn't seem to be much technical info on the streaming over wifi.

Evening all.
I recently bought a (non-functioning) NAD 7020e on flea bay for a smallish sum and, on examination, the primary of the main transformer (it has a smaller one to power the tuner) is O/C.
I pulled it out and had a look for the (now legendary) thermal fuse, to no avail. However, in addition to the wired in primary black/red wires there are, on the same side of the transformer and of the same gauge, a white/blue pair which were just blanked off with plastic doo-dahs.
My hope is that this is a separate 120v primary which I can drive with a suitable step-down. I shall (after disconnecting all the secondaries of course) squirt in a small voltage AC and see what comes out but my question is: does anyone know the nature of this thing? Is my hope foolish? I've been trying to source a replacement/s for the transformer and it's not looking good...

Cheers, Jon.

This question comes from an abundance of ignorance.

If you have a tweeter horn with a short throat in the same cabinet as a midrange/squawker horn with a much longer throat and they are both mounted to the same baffle/motorboard, there will be a phase difference near the crossover point which will cause cancellation.

What are the implications of putting a tube (no flare) between the tweeter compression driver and the tweeter horn, lining up the two compression drivers?

I have a pair of Klipsch Cornwall IIIs which exhibit a sharp narrow cutout at 5khz which is where the crossover frequency is between the squawker and tweeter when measured at 39" (1 meter M/L). I have read that tubes are used to create Hemholtz resonators, but I have no idea if this applies here or if there are other things I am not aware of that would muck things up.

Over on bbuterfield's thread, I posted some information from the Donald North patent.(https://www.diyaudio.com/forums/multi-way/330031-fractal-array-straight-cbt-passive-xos-eq-4.html)

Thought I'd break it off into a seperate thread, to explore it further.

First off, the original post:

================================================



Here's your design


The reason that your design has narrow vertical directivity and wide horizontal directivity is because the vertical spacing is wide and the horizontal is narrow. If you made the spacing symmetrical, you would get identical vertical and horizontal beamwidth. And then it would look like this design from Donald North. Donald North worked for AuraSound for over a decade, and also has patents on their 18" subwoofer, their NRT motor topology, and the motor design for the Aurasound Whisper

US6801631B1 - Speaker system with multiple transducers positioned in a plane for optimum acoustic radiation pattern
- Google Patents

Here's the North patent







Here's pics of the speaker

DNA Donald North Audio vacuum tube SET triode headphone amplifier

here's his website. There's a bunch of stuff that isn't indexed off the home page, use Google to get to it.

hi ,
i have this schematic , that works fine with mentioned transistors but now these transistors are obsolete , I have some 2N5401/2N5551 & MPSA92/42 available with me, can i replace them directly , will they heat up too much if i use 70VDC , how do i calculate the current in the VAS stage ?

Hi all,

I picked up an old NHT SA-2 and SW2P over the weekend and have had a couple of issues with the SA-2 amp.

First issue is the volume control doesn't work, it seems to be stuck on full volume. Not a big problem as I can reduce the output level on the AV receiver to balance it out.

The amp and sub were working fine for an hour or 2 but I paused the movie I was watching and ducked out of the room for about 20 - 30 mins. The amp went into standby mode but switched back on when I restarted the movie however there was no output from the sub. I had a closer look at the sub and when the amp switches on, the speaker cone gets sucked back into the magnet. Turn off the amp and it pops back out again.

I tested the sub with another amp and it works fine, so the problem is definitely the SA-2.

My electronics knowledge and toolkit is very basic, so I don't know where to start to diagnose the problem. Assuming its not an easy and obvious fix it will probably involve taking it to a service tech to get it repaired.

So my 2 questions are - is this a fault that an absolute beginner is likely to be able to fix?

If not, and it needs to go to a service tech, is it worth it? The cost of diagnosis and repair is probably going to be more than buying something like this Aiyima A3001 - AIYIMA TPA3255 Subwoofer Power Speaker Amplifier 300W Mono Hifi Home Audio Amplifier NE5532 OP AMP Bass Treble Adjust - AliExpress - 11.11_Double 11_Singles Day

Thanks in advance!

Here is a theoretical question, and googling did not help me answer it.

Let's assume a driver radiates through a layer of absorbtive material (like a layer of mineral wool, or foam). The sound radiates through this wall of material on its way to our ears.

The absorptive material has little absorption at 100 hz, but very high absorption at 1000 Hz. Therefore the sound that reaches our ears has been filtered.

Is there a phase shift associated with this filtering? On the one hand, I could imagine that the absorption process is a minimum phase process, so yes there is a phase shift. On the other hand I could imagine that since the decrease in SPL is purely mechanical in nature (thermodynamic friction process), it is not filtering in the same sense as an electrical filter, so no there is no phase shift.

Thoughts?

J.

i acquired a bunch of tubes and transformers a couple years ago and have just started going through them. i found 3 6gw8 tubes. i have a transformer that can make 250 volts for the pentode plate and i found a couple line output transformers that can be wired in series with the secondaries in parallel to make an effective 7000 ohm primary when connected to some scavenged 8 ohm speakers connected in series to make a 16 ohm secondary load. i also have an old 3w thordarson output transformer that's 2000:3.5 that should reflect about 8000 ohms on the same 16 ohm speaker setup. thoughts on which will work best?

i found the schematic at https://www.thecolonel.id.au/web_images/6GW8 circuit a.jpg and didn't understand why they put 200 volts on the grid and use the screen grid to control the signal? i'm also considering adding an extra gain stage using 12at7 or possibly a 955 tube (i have many other options but don't know what would be best).

can anyone make suggestions?
View attachment 906572

I've had a little free time on my hands and have been learning Hornresp
thank you Mr. Mcbean!

its possibly my search terms but i haven't found much leading in this direction so i ask if its possible or am i looking for a free lunch?

Oh sorry for the wall of text in advance and what is the preferred method of sharing the hornresp sims ? screen capture ? print screen to pdf works but I'm not sure how to post the nice pictures correctly any help would be appreciated.

i don't have any specific goal here but more of an experiment with learning in my free time and getting to build something in the wood shop
maybe making a set of speakers to listen to when I'm in the garage

After reading Patrick Batemans TL post that I'm sure everyone is familiar with
An Improved Transmission Line Alignment.

i modeled a speaker i bought a few years back but never used. oh and i have 24 of them so i need to do something with them.



Re = 7.2587 ohms
Fs = 122.4702 Hz
Zmax = 43.8634 ohms
Qes = 0.5247
Qms = 2.6462
Qts = 0.4379
Le = 0.2345 mH (at 1 kHz)
Diam = 86.3600 mm ( 3.4000 in )
Sd = 5857.5384 mm^2( 9.0792 in^2)
Vas = 2.7893 L ( 0.0985 ft^3)
BL = 5.6048 N/A
Mms = 2.9511 g
Cms = 572.2593 uM/N
Kms = 1747.4596 N/M
Rms = 0.8582 R mechanical
Efficiency = 0.9175 %
Sensitivity= 91.6439 dB @1W/1m
Sensitivity= 92.0663 dB @2.83Vrms/1m

The OD simulation looks nice but...
View attachment TQWTL.pdf
at 600-1000hzand has a huge jagged bat ear response

i tried the Backloaded horn
View attachment BLH.pdf
the first and second dips are substantial though.

then i tried a CH with a horn on each end
View attachment CH F-R.pdf

then i tried adding a small horn to the front of the OD to make it a CH but i left the back like a TQWTL the only problem is its not an offset driver anymore its mounted at the end of the pipe.
View attachment CH.pdf

im sure there are issues with this design but it seems to look a lot better.

i wasn't sure what to do with the front or rear chambers and adding stuffing in the TL really makes it look nice

can anyone lend some advice on what i can do ? is there something i can do to change where the driver is located at in the simulations to make an OD CH TQWTL

i think a Multiple entry horn maybe ? i have to do some reading if thats what its for i thought that was for the synergy type of horn ?

can i put a frontloaded horn over one driver and use multiples ?
or can i put a single FLH over a single driver and not the others ?

Hello i think to use Tang Band w5-2143 and Seas ca22rny. They have a similar sensitivity. Both drivers are very good for their price. What you think?

I have one .plays a very low volume Asian increase the volume or gain .it trips off ...when I lower it back it plays ..any ideas what maybe causing this.

Hi everyone! recently got an old pair of altec lansing 8558B microaudio 28 band programmable equalizers and a POD programmer model 28R from microdaudio. I had in mind to incorporate such EQ to my current system. The problem is: I can not set the frequencies due the DB9 cable is missing. I tried with a pin to pin cable (1-1,2-2, 3-3 and so on) and the programmer turns on and seems like it is working but there's no communication with equalizers. It shows the frequencies and levels are moving but not for real. No change on sound. Pins for ground and Vcc are okay , probably more than 3 pins match with position, however the programming can not be achieved. I drew a short schematics based on both Db9 terminals and still not clear. Does anybody know the pin configuration for this cable? thank you.

This Sanwu HF183 board has attracted my attention because it offers both Bluetooth and remote control at a good price. The sound quality is pretty decent, but the gain is too high, so I decided to mod it, without much success.

Seeing there isn't much information online about this board, and having already removed the heatsink to mod the board, I decided to take some detailed photos of the board circuit for future visitors' reference. (R27 was originally an 100K ohm)

This board came pre-assembled with the heatsink, which was glued with a rubbery substance and very difficult to remove. Once the heatsink was removed, I noticed R28 was a 39K resistor, and assumed it was configured with 32db gain. I am pretty new to modding, so couldn't quite figure out which resistor to remove to drop it to 20db gain. I ended up removing R27 (100K ohm), but that didn't work for me. That's where I stand as of now. 😕

We have been developing a digitally-controlled precision LDR-based preamp for the last four years.

It's finally a mature design that includes a variety of control options and a very nice OLED display in addition to very precise control of the LDRs, and we're making it available on our website at BTFSystems, and answering non-commercial technical questions at our ongoing diyaudio thread here

You'll find lots of information about the development phase on diyaudio, and more photos and current information on the website.

Saw an old thread on here that didn't seem to go anywhere, hoping now a few years later there's an option.

I'd like to build a 2.1 soundbar with internal amps/power to keep my setup clean like it is now (older Sony soundbar).

I see a lot of plate amp, and amp boards for sale but not sure how they'd work for volume control, unless maybe using the headphone out jack on the tv?

Can you get an amp board/plate with hdmi/arc? Or do I need to go online and buy a cheap used soundbar and gut it for the electronics and I guess replace the crossovers (if separate).

There is a Peerless subwoofer/bass driver for sale on eBay (UK) with the model number of
P832953 and is 10” in diameter. I have searched but nothing comes up. Anyone got any ideas about it?

Cheers

WTB for some experiments i am planning for a phono stage a pair of 6072 tubes, also willing to exchange for other similar NOS JAN double triodes you might need.

Thank you!

I have a sub amp that keeps blowing the input fuse.

Is there anyone from the uk who would be up for repairing it?

I presume its the main power supply board thats an issue. Board number is 600109 rev5 and has a 66037 rev2 on it

Hello,

I have in my stash a set of small pushpull output transformers and visually matching power transformers. The OPTs are Z=10k max 10W with screen taps. The power transformers have 270-0-270 VAC 50mA, 5VAC 2A, 6.3VAC 1.5A windings.

I was thinking to build as good a power amplifier as I can, using these and other good components I have in storage. I came up with the idea to do a differential amp using 6N6p as power stage and 6N1p as driver stage. The plan is to use it as a tweeter amplifier in my active Linkwitz Orion speaker system, so it will only handle frequencies above 1500 Hz, I'm thinking the approx 2W max output should be sufficient for dedicated tweeter amplification (?).

It has been a number of years since I built my latest tube amp so please take a look at the schematic and give me your opinions. Is there something that will not work correcty, or can be improved without to much hassle?

Hi there,

finally after a long, long time I'm able to toy around with audio!

I want to build a simple vented speaker design (17l enclosure, port tuned to 40 Hz) and adapt it to work as bookshelf speaker.

In the shelf, the speaker is about 1m from the floor, but integrated in the shelf it has no distance from the "rear" wall (as it is flush with the shelf). Also sidewalls/corners are within 0.5m or so, so there will be a strong bass boost (at least 6db) due to these conditions.

To put a speaker into a book shelf is a difficult and suboptimal location, but it certainly occurs very often in real life. Nevertheless I cannot find much design info about that online.

I thought of building the speaker as closed design to cope with this bass boost.

What are your thoughts about this?

How do you design speakers for use in book shelves?

A thread for the discussion of ITD, it's effects and usefulness in stereo reproduction via loudspeakers in a room.

I found this paper interesting https://core.ac.uk/download/pdf/101155.pdf

Hi, I'm new to this forum; I hope someone here can help me with my guitar cabinet dilemma!

I'm looking to build, buy or modify a lightweight guitar cabinet for use with my fully-hollow archtop guitar. The guitar has a single magnetic neck pickup and an internal DPA mini condenser microphone; I like to blend the two sources together or switch back and forth between the two. I may eventually replace the mic with a transducer-style acoustic pickup to reduce feedback issues but regardless, one of the sources will require a full-range speaker system.

I have a couple of old octal tube amp heads that I use at home, but for gigging purposes I will probably go with one of the many small solid state amps that are currently available - Quilter, Acoustic Image, Henriksen, Raezer's Edge, etc., so I'm looking for a passive, full-range speaker cabinet to use with one or more of these amps. I would also like to use the same cabinet for acoustic guitar.

Finding a cabinet that sounds equally good for both electric and acoustic guitar pickups usually requires some sort of compromise and I'd like to get some advice on this subject. Eminence alpha/beta speakers and front ported/closed back Raezer's Edge cabinets with adjustable tweeters are the usual choices in these circumstances, but these eminence speakers are not the first choice for most electric guitarists. Also, these Eminence speakers have a limited frequency range that tops out around 3500 hz, which is not ideal IMO. My understanding is that archtop guitars have a harmonically rich spot between 4000 & 6000 hz, and ideally the main speaker would have a range that would include these frequencies.

I had a thought: I have access to a NOS EV Force 10 speaker, which has a range of 75 - 7000 hz, and am wondering if perhaps this would be a good choice. Along with the Altec 417, 425, etc., I think the EVM/SRO speaker lines were originally designed as more of a general purpose PA and musical instrument speaker (correct me if I'm wrong); they just happened to be a great choice for electric guitar cabinets. These speakers all have a wide frequency range topping out in the 6000 - 8000 hz range.

So my questions:

Would the Force 10 match well with a tweeter/crossover/LPad for an extended range closed back ported cabinet? I realize that these are heavy speakers (EV Force 10 is 13 lbs, for example), but perhaps a lightweight pine or 1/2 plywood cabinet could make up the difference.

What sort of crossover should I use? Passive or active? What frequency should the crossover happen at? What tweeter? Cabinet design recommendations?

I'll consider anything that would be suitable as long as it is not overly large or heavy. Thanks for your time and stay healthy!

After my measurements on the A04 (https://www.diyaudio.com/forums/class-d/360821-aiyima-a04-tpa-3251-measurements-maybe.html), the manufacturer offered to send me a 07 amp for review. They also included a PSU in the 'kit'.
Below some pictures and scope shots.

First scope pic is before and after output filter at idle, second is a 1k sine.

Will post measurements in next post.

I just got a YBA Complete which uses a Sony drive. I can push the door open button and it opens and stays open, but if I push it to close the door it closes and reopens and cycles like that until I power down.
Has anyone had that problem? If so how did you resolve it?

Hello

Doe's anyone have pcbs for sale for this project?
Appreciate your replies (per e-mail too).

wennsblitzt

I would appreciate your thoughts as a sanity check for me, for the design below. Nothing new here, a preamp for low output sources (400mV to 1V - for a portable cdplayer and a guitar)the intention is to use some LSK489 I have, and 9V Vdd single supply. Gain of 2 should suffice.



I am going for a self-biasing topology, as basic as possible (for the time being at least). For 9V Vdd, I chose Idq=9mA for Vgs=-0.8V Datasheet says Vgsoff=-3V and rds=300 in my case, so Rs=330Ohm and Rd=367. Do these numbers sound right? I think there is enough headroom for the input signal I am interested in.




Any suggestions to convert mono to stereo? Like a cheap and cheerful transformer?



Is there an alternative to input and output capacitors?


Cheers!

Hi All,

I working on a design of a round speaker consisting of a 12 inch subwoofer and a full range speaker opposing each other with a horn around the equator of the orb.

The benefits of not having straight box type edges should help reduce resonances.

I am curious about how diffraction will work on the design? Any ideas.

The speaker will also be DSP tuned and amplified.

I'll post a picture of the design I'm working on.

I found a pair of Chorus IIs not to long ago. I have been collecting parts to build an Aleph J, as Klispch have always been said to do great with low power.

The more I read about the Chorus a lot of people say that despite being very sensitive speakers they really shine with more power, 150-200 watts.



I am considering switching to a Honey Badger build, which seems like it will be a better fit. Downside is I'm out (for now, prob build it eventually) the money I've so far invested in Aleph J parts.



Recommendations for an amp to run the Chorus IIs?

Hi everyone I'm new here I'm having a problem with a yamaha rx-v459 amp.it was first dead(no power). I replaced cap 223k 630v with same value now it switches on then off. If I put it in diagnostic mode it gives me TMP prt000h it is not showing voltage for ps2-000 where do test for ps2 voltage your help will be appreciated?

I've been listening to Dolby Atmos Mixes of new and old tunes on Tidal, and the difference is pretty stunning. Something I've noticed in each one is a rock solid center, and I'm not even using a center channel (yet). I think this is because of a long standing suspicion I've had: that a lot of music studios don't have their speakers set up properly (just look at pictures online, many have monitors, sitting atop the mixing console, above your head, not toed in properly, etc) while I believe that Atmos mixes are likely being done in proper film studios, which have industry required standards.

I also listened to Atmos tracks in stereo and upmixed Dolby Surround and the imaging was STILL better on everything I listened to.

I really hope Atmos mixed music continues, and more audio enthusiasts give it a try in their system. If you've tried it, what are your thoughts?

Just finishing up a little project I have been working on: taking 2 ubiquitous Logitech X-230 2.1 computer speakers and making a 2.2 system with them.

In doing this I found that a lot of information on the web about these systems is missing or incorrect, including the pinout. So here is how it really works:

DB-9 pinout, cable side:
pin 1 = short to pin 7
pin 2 = purple = R in
pin 3 = yellow = R spkr +
pin 4 = red = L spkr +
pin 5 = green & shield = GND in
pin 6 = grey = sense
pin 7 = short to pin 1
pin 8 = (black = R spkr -) & (blue = L spkr -)
pin 9 = brown = L in

TRS pinout (I know this is flipped, trust me):
Tip = red = L
Ring = white = R
Sleeve = shield = GND

Operation:
plugging in the DB-9 with shorted pins 1 & 7 turns on the master power
satellite power switch off = grey shorted to black
satellite power switch on = LED + 1.9K in series between grey and black

Y cable to make a 2.2
purple -> R
yellow -> R
red -> L
green -> L+R
grey -> L+R
black -> R
blue -> L
brown -> L

WTB:

Looking for a single (qty 1) of these .50 cu ft curved cabinets, gloss black finish.
Dayton Audio TWC-0.50BK 0.50 cu. ft. 2-Way Curved Speaker Cabinet Gloss Black

These have been discontinued for quite a while, thought someone may have a single leftover.

Greetings,

Just a question about the DIY CSS Speaker packages.. Specifically the CSS Model P215 Kit or either of the Criton kits.

As you may know you can purchase these kits both assembled and finished nicely or as kits with a flat pack. The price difference between the kit and the finished speakers is roughly 2k, so substantial. The finished speakers look very nice, whereas the kit just provides bare wood.

My question is, other than aesthetics, would the sound quality be the same if I bought the kit and assembled it as-is. Without finishing the wood or anything extra other than assembling the supplied wooden frames.

Thank you!

I have a fully working Sony TA-5650, with the varactor diodes already replaced, here. I ran the amp for some time and must say that I'm quite surprised by the sound of this vintage V-Fet amp, especially bypassing the preamp section and using it as a power amp.
However, I also have the fear that the amp might fail sooner or later due to a bad cap and therefore only had the amp playing music for a day in total.
I haven't worked on any V-Fet amp before and since some little mistake could kill the unobtanioum V-Fets, I thought it would be better to get someone else to do the job this time.


Does anyone know someone who worked on a couple of V-Fet amps before, is located in Europe and would be willing to fully recap my amp, change out the bias pots and maybe do some recommended mods like the double-diode mod for the voltage doubler described in this thread?


Thanks for any input 🙂

Greetings, I'll do my best to shed lite on my dilemna-I have a Bedini thats gone MAD after I installed BG caps on driver boards. Amp gets hotter on lft ch. than rt. ch. Has a hum. We have disconnected both driver bds. & ckd. power supply- both caps power up evenly within a 1/2 volt. Hook up left driver bd. only & get a1.5volt diff. reading on rt . power cap. This uses asplit power supply. b+ & B- give same values on Ps-caps. only wire common toboth bds hooked up is floating grd from PS board. hope this helps!!! Tkx Ronnie

I have three stereo pcb's going spare.
Built and tested.
Requires valve (12au7 or 12ax7), power supply and heatsink.
£18 each plus p+p £4.20 to UK only.

Hi all,

I'm looking for help on a DIY Amp selector to switch between AVR and stereo amp for one set of speakers.

I know this has been covered a lot but I'm struggling with finding the correct rated (4PDT or 4x3 rotary or similar) break before make switch.

***
Background

I have the current setup - an AVR amp with pre out to a stereo amp to drive front speakers. Everything stereo related is connected to the stereo amp and everything TV related to the AVR.

Now as the stereo amp is older it has no AV bypass therefore I have to set the volume to a specific position on amp each time I go between stereo and AVR as well as turning on another amp every time I use the AVR... anyway I want to get away from this by selecting the amp to use with a simple switch in line on the speaker cable.

The speaker cable is two twists of 14awg per terminal (total ~11awg) chunky but sounds great and I will use the same within the switch box with screw/banana type terminals

***

Calculation for switch rating

Stereo Amp power - 110Watt per channel
Speakers - 8 ohm

Thus using R=V/I and R=V²/P

DC Voltage - 29.66V
DC Amps - 3.71A

***
Options I have found.

Option 1.

I would like a rotary switch and people have suggested ones such as these in previous searches which I like the look of and could be just right...

Elma - 2A @ 42V
https://uk.farnell.com/elma/01-1433/switch-4-pole-3-pos/dp/1876080

Greyhill - 5A @ 28V
https://www.mouser.co.uk/ProductDetail/Grayhill/44UA45-01-4-02N/?qs=ls7QRyWmRk4KuC7xeL0ZtA==

Lorlin - 1A @ 24V ac/dc -
https://www.mouser.co.uk/ProductDetail/Lorlin/CK1457/?qs=VJkHNLJxjTeoQOv%2BImgcpg==

These seem to be suggested a fair amount however the rating is lower than I have calculated for above and I'm concerned the contact size maybe a bottleneck for the speaker cable. Am I missing something here?

Option 2.

Multiple stacks of these switches to get the additional amp rating up and splitting the inputs/outputs between the two layers (ie an 8x3 switch rather than a 4x3) . However more posts have warned against this method as one contact could in theory be made before the other thus taking the full load rather than half and overloading the switch. Is this really a likely scenario to happen?

Should I actually be worried about that and surely this would only happen if switching to an amp already playing at significant volume?

Fidelity-Audio

Option 3.

I have seen other posts with the following type of switches but not really a fan of the look and they seem pretty low quality (not gold contacts etc) I want to get away from this but it may be the only option...

https://cpc.farnell.com/multicomp/m...gle-4pdt-on-on-sq/dp/SW05736?st=4pdt switches

https://www.ebay.co.uk/itm/Heavy-Du...-/272304082452?_trksid=p2349624.m46890.l49292

Option 4.

Then there is a large jump to the industrial style switch... But this seems overkill and again not great contact quality?

https://uk.rs-online.com/web/p/rotary-cam-switches/0758642/

https://uk.farnell.com/schneider-electric/k2h014uch/rotary-switch-4pole-14-6a-230v/dp/3108369

Option 5.

Supply separate power and use relays to switch between. To be honest passive would be my preference rather than overcomplicating this but if I can't find a rated switch this might have to do.

***

Any help would be appreciated in either reassuring option 1 or 2 or suggesting another option that I have yet to find in the hours of trawling the internet! Opinions welcome 🙂

Many thanks in advance.

Sam.

I need to replace some broken resistors in my CAS-2 power amplifier.
What i can read from the colour codes, see attachment.
10 ohm tol 0,02%
0,68 ohm tol 10%

In need help some help finding the correct resistor?
Power Rating
Manufacturer ( there is a lot to choose from) Resistors | Hifi Collective

Should i change them all of the or only the broken ones?

Best Regards

Jonas

Can Delete/Close Thread (ES9028Pro Found)

ES9028Pro Found! No longer needed. Can delete this thread.

I sort of got screwed/confused by a Chinese Ebay seller who never requested payment for the ES9028/ES9028Pro primary IC and just shipped the incomplete DIY kit, but they included the R-Core transformer! Basically they sent me everything needed to run the DAC except the main IC for the DAC... haha. They even sent me a message asking me about which IC and I told them the ES9028, but they sent me a blank board without ever asking for payment.. We had 3 or 4 messages back and forth and this still happened.

What makes this even better is the very first message I sent to this company/person was to ask if they would solder the main IC for me and leave the rest. Well, they soldered random SMD components which I can easily do.. I even told them I don't need their op-amps if that could be offset with better alternatives for my other parts I do need. It's like none of this registered the whole time and the main Ad says nothing about missing cost of IC in the cost. I have no problem soldering in this kind of IC with SMD parts as I do have a hot air re-worker and I can do it with a standard iron too. Have flux and soldering paste along with ChipQuik.

I was wondering if anyone has any idea of the best place to get an IC like the ES9028, that is the one I was going for. I have seen ES9028Pro's going for $70 on Ebay, but my upgraded LED display kit needs the ES9028 to work properly according to the seller. Or perhaps someone with an ES9028 is looking to jump to the 9038, I would definitely take a used model for a reasonable price (say ~$40 obo) to help out on paying for the ES9038.

Below you can see pictures of the PCB without the main IC and I included grabs of the ebay seller because I have seen them disappear many times.


Note: The very first picture of the PCB is one I took and is what I am working with.

I have a pair of QLN Splitfield Signature speakers and I absolutely love them, unfortunately one of the tweeters died the other day and needs to be replaced.

The tweeter that is in them is the Scanspeak D2905/9000 which isn't made any more, it has an impedance of 4 ohms and a sensitivity of 90dB. I guess the obvious thing to do would be to replace the tweeters with the Scanspeak D2905/9500 tweeters (6 ohm, 90dB), but I'm wondering if I can do better and if so whether the advantage over the D2905/9500 would be really noticable. I'm limited to an overall diameter of 104mm. I'm tempted by the look of the response on the Scanspeak 2904/730001's, but guess I'd need to attenuate them a little using an L-Pad since the sensitivity is up at 94dB. So I'm kind of thinking using a resistance of 6.84 ohms for the series resistor and 1.476 for the parallel resistor (or as close as I can get to those values).

Anyway, I guess my question is, do you think the 2904/730001 with an L-Pad would greatly out perform the D2905/9500? Are there any other tweeters that I should consider?

Any help would be much appreciated.

Kind regards,

Andrew

Hey all!

I'll preface this thread by saying that i'm not a complete noob to electronics, but i'm damn close to it so please bear with my apparent lack of technical knowledge 🙂

Last year I built a simple passive footswitch out of 2 3PDT switches, some LEDs and the appropriate resistor (which i can't remember the value of) for a 9vdc connection. I'm using it to switch between piezo and magnetic pickups on my guitar. I've attached a simple wiring diagram for you all to ridicule haha.

I'm having ground hum issues between the two outputs, so I have two questions for y'all:

First, I'm wondering if there's anything i can do to to improve the wiring of the box (Ground loops?).

Second, I've thought of adding a 1:1 isolation transformer to the 2nd output of the switch, but have no idea how to pick one based on the output impedance of the piezo on my guitar (Again, not quite sure as my multimeter is at work... The suggested trim pot for passive installation is 5Mohm if that's any indication :/).

Any suggestions are greatly appreciated. Thanks!

Good morning everyone. I am looking some older mark audio drivers for a project..The Alpair 6.0 and the 6.2 drivers. I'm looking for a new or nicely used pairs of these drivers..Just pm me or you can e mail me..

marchj313@gmail.com. thanks Jeff