diyAudio

Bob de Builder · 2022-05-29 9:41 pm

I've shared this on the Klipsch Community general Forum and hoping I'd also get some collaborative help and feedback here. Wasn't sure where on which forum to post this as it covers a multitude of inquiries but most importantly setting up the system I have in mind.

Reaching out for help from anyone in the community with knowledge, advice and expertise when installing a system in a commercial restaurant space. Writing this in a beginner-friendly tone because that is where I am now. I've been a lurker taking notes who has finally convinced a friend to splurge on a sound system that will be an exciting feature of his restaurant that I'm collaborating on. A high-efficiency horn-loaded system powered by SET tube amplifiers is the path I've chosen to approach this project.

The restaurant's build is almost complete, with interior finishings currently being applied. I've attached images of the floor plan and sections of the space with coloured markings for the whereabouts of the D.J. booth and speaker placement proposal for anyone interested in size and layout (yellow: booth, pink: speakers). A key with materials used is also included - there isn't much leeway to apply acoustic treatment. Maybe pyramid foam within the waffle spacing of the concrete ceiling. I also feel like the large floor to ceiling windows and wall tiles would create a lot of reflections, especially with how I'm planning to orient the speakers. I have suggested adding thick drapes to help remedy this for the owners, and there would be a few carpet art pieces hung that help in absorption as well.

I'm proposing 2 budget options:

Option 1 / Big-Budget Features:

2-3x pairs of Klipsch Hersey IVs - suspended or mounted on walls/columns upside down with a tilt angle. The horns would point downwards at the customers and the woofer closer to the ceiling to create a similar low-end response when placed ordinarily in a floor-standing position. The speakers will either be suspended by eye bolts and fender washers hung from a concrete beam waffle structure or mounted on french cleats on the structure's columns. They will be powered by:
2-3x Decware Super Zen Triode Amplifier would love to pair the Decware tube amps with the HIVs, but I'm concerned if they have enough oomph to drive the speakers to volume when it's a busy day at the restaurant
1x Condesa Carmen in-house analogue D.J. rotary mixer
2x Technics SL-1200MK7 Turntables
1x DAC/node streamer - undecided [BLUESOUND NODE or the AUDIOPHONICS RASPDAC an option for this budget]
(DAC connected through USB or wirelessly streamed via Spotify Connect - Streamed via an iPad through a lighting cable to USB adapter or wirelessly through Spotify Connect connected via a node, respectively (streaming via chrome-cast is not an option because of its inability of gapless playback)). I've also heard that the new YAMAHA RX receivers act as streamers for Spotify Connect and other applications.
1. Possibility of an independent DAC Schiit Modi 3+ for better sound (as subjective as that is for the setup)
1x Receiver to route all the incoming signal sources to the designated amplifiers and speakers - Need help in this department.

Option 2 / Small Budget differentials:

3-4x Klipsch RP-600M II - also considering fitting them upside down with a tilt angle. The horns point downwards at the customers and the woofer closer to the ceiling to create a similar low-end response when placed ordinarily in a floor-standing position. But the 600 IIs would be mounted on the walls/columns versus being suspended from the ceiling.
3-4x Reisong A10 - I heard great things & felt they'd be a good fit for the more budget friendlier option, but I'm concerned if they have enough oomph like the Decware Zen triodes to drive the speaker in a busy day
1x Vaira Instruments RD20 in-house analogue D.J. rotary mixer

There are a few missing puzzle pieces in the system due to my lack of experience, and I was hoping that anyone could kindly assist me. Looking for a receiver that will take the 3 different sources (in-house D.J. mixer output, DAC-Streamer Spotify output & guest D.J.'s controller output) and send the output signal to all the amplifiers powering the speakers. Would home theatre A.V. receivers work? I've checked the backplate of most A.V. receiver products, and they all have 'surround', 'front', 'center' labels for the different speaker outputs. I'm worried about whether each pair of speakers would get other signals - which wouldn't work in my application.

I've also done my best to map out how the sound system component network would work with a resident D.J. system in a booth, guest D.J. with an external mixer, and DAC for regular musical playlist programming when there's no D.J. performing.

Would love to hear everyone's advice and thoughts on how I've designed the proposed system and mapped it out. I'm not sure if I've got the number of speakers right - it's tricky since where I'm located doesn't have proper HiFi audio dealers in the country - I can't test any components. The purchasing decision must be made based on faith and expertise. As you now learned, a lot would be riding on this

This project aims to bring a hi-fi experience to a population and culture that is not exposed to it and be inclusive in presenting it the best way possible with the budgets at hand.

Your input would be greatly appreciated!

P.S. Any thoughts of anyone who had listened to the active Superwax mini by Pitt & Giblin from Australia compared to Hersey's or other speakers from the heritage line-up?

fishball79 · 2020-04-24 5:57 am

From the legendary but sadly now defunct Welborne Labs.

Although meant for the Oris Horn, there is no crossover nor EQ but just a direct bypass for the fullrange output.

Bass output is crossed 2nd order at 180hz.

Upgraded with Elna cerafine capacitors and other goodies.

Comes with complete documentation and manual.

USD500 negotiable

sploo · 2022-06-01 5:46 pm

I appreciate this might be a bit of an open ended question (and highly driver dependant) but, if you have a mid-bass driver that is better suited to a ported enclosure, is there any significant downside to using it in a sealed enclosure if you plan for the bass frequencies to be handled by a subwoofer?

The specific example is a Scan-Speak 21W/8554-00 8" mid-bass, which has an Efficiency Bandwidth Product (EBP, or fs/Qes) of 92. I understand that values under 50 are generally better for sealed enclosures and over 50 for ported; so this driver is very much in the "port it" range.

The predicted response for the driver in a 40 litre ported enclosure vs an 11 litre sealed indicates that it should be very similar down to around 130Hz, and only differing by ~2dB at 80Hz. If I were to use an 11 litre sealed design with a separate subwoofer crossed over at 100Hz, would this likely "work" (in the sense that there should be no negative consequences over 100Hz, and on the assumption the sub would provide sufficient bass below 100Hz)?

Tesla Audio · 2021-09-21 12:16 pm

Diaphragm for Ribbon tweeters any size up to 25mm width, length unlimited. With or without corrugation. Thickness 5 microns.
Price up to size and complexity. Paypal payment.

John007 · 2008-03-19 4:23 pm

Hi all, i have TDA1541 OS DAC and i need cheap high quality low powered SS amp "kit" for the DAC. I like the sound of the new Harman Kardon receivers, they have very clean sound almost like tube amplifiers with strong bass, is it possible to copy the amplifier, or any kit (high-current, ultrawide-bandwidth) amplifier?

tktran303 · 2022-05-09 2:23 am

Hi,

I'm looking for a high dynamic range dome tweeter in a standard 104mm faceplate.

I need something that hits 110dB/1m without dynamic range compression. ie. no loss in output when compared to 80dB@1m.
Needs to be able to cross around 2KHz- 2.5KHz with 3rd order electrical filter.

Rbertalotto · 2022-05-25 12:42 pm

New Emotiva amplifier does not have an AC ground.......OH NO!

zman01 · 2022-05-31 12:23 pm

Erin's review on YouTube:

Login to view embedded media

rehepapp · 2021-10-16 6:13 pm

Looking Candeias Engineering CC80 balanced amplifier modules.

sachu888 · 2020-10-08 4:57 pm

Looking to buy CDM4/11 transport for my Philips Cd -472 CD player. My player's transport has been broken in transport.

Regards
Sachin

Michael1103 · 2022-05-24 7:40 pm

I recently ran an experiment with a small box and a midrange driver. The goal was to test the effects of different stuffing materials on the response. I shot these sweeps on REW and kept all the variables the same besides the materials used for stuffing. I'm not really sure how I should be interpreting the phase response graph and what is ideal.

Test 1: No stuffing, empty box

Both the frequency response and phase response are jagged. The pattern is broken up around 13khz, I'm assuming that is some kind of driver breakup causing a spike in FR.

Test 2: lightly stuffed with polyfill

In this test, the phase response seems to have flattened out significantly. My assumption is that this is a good thing since that means the different frequencies are more or less aligned closely?

Test 3: Tightly stuffed with polyfill

With the tightly stuffed polyfill, the phase response has gotten very smooth and linear. The FR has also smoothed out quite nicely.

So my question is, what is an ideal phase response? Subjectively speaking, what should a good phase response sound like?

Veleric · 2022-05-14 12:14 am

I'm thinking of buying or building a simple sealed sub. Building would be fun, but I have other speaker projects that keep me occupied, so I don't absolutely need another one. So the question is this: If I have $500 to spend, to either build or buy a powered, sealed subwoofer, could I do much better than this SVS SB-1000? They claim an F3 of 24 Hz (is that believable?).

https://www.amazon.com/dp/B00AF88C0...82059&linkCode=osi&psc=1&tag=c_1c_a_o-20&th=1

My main interest is music, not home theater. And I'm sure I don't need 300 watts, 100 watts would probably be enough.

I want to end up with a compact powered, sealed, subwoofer. Is there a driver and plate amp I could buy for less that could be much better?

Thanks,
Eric

electronicsman · 2022-04-26 2:42 pm

Greetings!

I got a good amplifier from a friend, the Carlsbro Powerline pro 2000. the main issue is, that the driver boards are missin.
I only have the transformer, power supply, input and output boards and potentiometer boards. I powered everything up, and the outputs work fine.
I dont know where the VAS and the IPS are located, i dont know if they are missing. I would like to kindly ask everybody for a schematic.
Without it i am in complete darkness. I would like to design around these boards, as i could get a really powerful PA amp out of them.

v4lve lover · 2021-03-05 6:33 pm

I have some vintage Germanium transistors i want to get rid off to pay some bills.

And some tubes.

I prefer to sell to EU customers because shipping overseas can be prohibitively expensive

TKO956 · 2022-05-30 5:52 pm

Hello All,

A friend of mine wants help building some speakers for his workshop. The space is about 1300ft2 of almost open space.

Currently he is using a Rogue Sphinx to power some Klipsch KLF30sthat are about dead: couple of woofers no longer working, one crossover needs to be rebuilt, one tweeter needs to be replaced. He's interested in building some new speakers instead of repairing the Klipschs and really likes the look of the Liionidas speakers from Lii Audio. https://www.lii-audio.com/product/p...drivers-simple-and-musical-complete-solution/

I'm worried that these won't be able to fill his workshop like his current speakers.

Any thoughts or recommendations?

TIA

andyjevans · 2022-06-01 5:39 pm

I have collected several European radio triode valves from the 1930s with bases like side contact, B5 and B7. Some with added diodes and top caps. They all have a gain (mu) of 30 or over and I have used them as drivers in my 2a3/300b amps. They sound wonderful and are little known gems, typically collected by radio enthusiasts for renovating old radios. Excellent as a driver stage or a line stage.

I will be offering several in this thread like REN904 types, MH4, AC2, ABC1 and so on. Most are 4v filaments, and there are also 13v/200mA versions. All are tested good. Many are very pretty with their gold or silver metallic coats. I also have a variety of bases like original side contact ones,

since Chinese ones don't work. Contact me for more details.

So to start with here are some AC2 (4v) and CC2 (13v) plus 4D1 (13v). I have several more of each type.
Pair of 4D1 new in box £8
Pair AC2 Tungsram new looking £22
Pair of CC2 new in box, unopened £22

I will be listing many more in this thread. For details PM me or contact performanceandmedia@gmail.com Andy

jrenkin · 2021-03-20 6:44 pm

Well used but not by me. Large phase plugs (wood), damping goop around magnet. Work fine, great shape.

$100 plus shipping, continental US only

anthonybest1 · 2022-05-26 2:11 am

Hi everyone,

i really need some help. I recently was searching eBay for a vintage Yamaha Amplifier. I wanted the A-760 but searching eBay for North America around someone selling an A-6. Well I didn’t do my research and just thought I’d was the same as the A-760 just Yamaha having the same amp with just another model number not realizing it was a Japanese model for 100 volts not our 120 volts. So basically to cut to the chase what do I need to do to it to make it a 120 volt model?
New power supply and a couple other things?
Will parts off the A-960 work? I just want to know what’s different between the A-6 and the A-760. The guy I bout it from said it works fine which it does except if there is a spike in power I can see it blowing. 100 and 120 is a big difference.

Thanks everyone

anthony

perkri · 2022-05-31 7:21 pm

Hi,

I’ve tried to understand how to fix the thump when powering down, but I’m a bit overwhelmed from reading through the thread…

The VFet I have is the second version in the offering, and with my Cornwalls, there is a rather “potent” thump when powering down.

Trying to figure out how to best fix this problem, and and help with this would be greatly appreciated!

Thanks!

Per

Brian Beck · 2006-03-27 3:33 pm

Can anyone help me with documentation for these Oregon Electronic HV supplies, model D6? I could use at least the schematics and specs.

I saved these two beasts from the trash bin many years ago when my first employer was about to toss them out. They have rested in peace in my garage for 25 years awaiting my attention. I have no documentation, and web searches have brought me nothing useful. This company seems to have vaporized. I wonder if it might have been a spin-out by Tektronix employees. Both units are the same model although the front panels are different colors. One unit has a date code of 1956 on a choke.

Each unit has two separate HV regulated outputs, each adjustable from 0 to +600VDC. The raw +650VDC supply is brought out front too. These two outputs can be used separately or in parallel. There is an adjustable negative bias supply, 0 to -150VDC. A heater supply of 12.6VAC CT at 10A is available on the front terminals too. Meters indicate up to 600V, and 500mA. Tube complement includes six 807, one 6X5GT, two OD3, two 5R4WGY.

They would make useful bench supplies for any tube project up to and including large power amplifiers.

Does anyone know anything about these? Thanks in advance.

An externally hosted image should be here but it was not working when we last tested it.

Zoef · 2017-06-18 3:58 pm

Looking for a pair of Tannoy 3833GG drivers.
These where used in the dmt 15 and the Churchill.

planet IX · 2022-05-19 9:08 am

EF14 pentode in steel housing

I'm offering 2 pieces of Telefunken EF14 in a closed and sealed box!
The box is sealed with a banderole under the flap which has not been opened.
So these are 2 tubes in the condition in which they left the factory!

Since I don't want to open the boxes, I can't say anything about the condition of the tubes themselves.
But it can be assumed that they are in best conditions.

Private sale: no guarantee, no return.
180€ + shipping

smg43 · 2022-06-01 2:25 pm

Does anyone have a spare 15vac 100VA+ transformer going spare, ideally something decent such as Noratel.

Based in UK.

sal_cats · 2022-05-23 9:05 am

A pair of mark audio super pencils with the alpair 12p drivers.

Looking for £325 and will have to be collected from Bristol, UK.

Pair of emoto ultra ribbon super tweeters sitting on top. I am happy to include them in the sale for an extra £40 if someone is interested. I managed to drop one of them since owning these so they're not in perfect condition.

Thanks

Canadaf150 · 2022-03-04 12:51 pm

Hey every, found this forum quite useful over the past few weeks so decided to join.

Recently started collecting older stereo gear, you know, just for fun and set up a test bench in my basement. Recently scored an audison lrx5 a single din pioneer premier deck thats never been used and a pair of older 5 1/4 pionner coax for $120. Just thought id share that excitment but thats another story.

My current system in my f150 consists of a kenwood dmx7706s
4 6.5 tc sounds tropo
Sundown saz1000d
Hertz hcp4
hertz mpk165.3

The reason for this post is i found what looks to be a decent set of hertz hsk 165xl. He was originally asking $400 but ive got him down to $290cad.

Only issue i can see in the pictures is that the crossovers are missing the plastic snap on covers and 1 terminal screw. Ive been googling for a day and cannot find replacement crossovers for these. Closest i can find are the 2tw10.4 crossovers that 'say' they are for the hsk set but im not so sure. Whats everyone here think of mismatching passive crossovers on sets? Maybe i can use different quality passives? Or should i just rock these without the covers? Worth $290 canadian? How do they compare to the mpk165.3?

Next question is, ive never really used 1 of those external active crossover things. I dont really want a dsp as i dont own a pc at home. Can anyone give me a quick low down on how i can incorporate an external active crossover into my system using a single 4 channel amp. Id love to try out active but this is my first time. Is it as simple as hooking up the rcas the mids and tweeters and then just adjusting the crossover points for each?

dimkasta · 2021-04-23 4:10 pm

I just bought this little amp for a very good price. The first impressions are very positive. It looks nice, it has a 12" speaker, the sound is decent and it's far louder than what is acceptable at home.

However...

It has a very audible hiss. It's irrelevant while playing, but if you leave it on while you do other things it gets annoying.

The guts are a bit disappointing. SMPS and a TDA7294 circuit on the same board. And both channels go through the DSP on the front side.
I am afraid it's one of those devices that are destined to end up in a landfill after 5-6 years (unless you repurpose it or something).

The nice thing is that the chassis is roomy with lots of space for custom stuff.

So the DIY/mod plans so far are

Add a 1/4 jack/plug so that I can reuse it as a cab
Eventually change the speaker into something nicer
Replace the SMPS with a nice lower V chunky transformer (and glass fuses), a normal and properly filtered bridge rectifier, and nice big CRC filters.
Replace the 7x15 regulators with nicer ones with lower impedance and less noise.
Replace the TDA7294 circuit with an LM1875 at 20W (or even less, I will have to coordinate the PSU first) and proper beefy capacitance
Change the crappy plastic switches/buttons with nicer metal ones
Add a buffered FX loop
Prepare for replacement preamps or something for when the DSP goes to the big gig in the sky

Any other suggestions?

stofbj · 2022-01-20 4:45 pm

Hi,
Hope someone can help, I had one channel blown on a sony TA-2650 so replaced the pre drivers and two matching pair of power transistors, powering up with
lamp tester I noticed the bias would shoot up and found SV04F (diode D101 & D201) faulty, If i rapidly cool it with freeze spray the bias shot down again. So got 3x 1N3595 in series mount on the original mounting expoy resigned to the mounting and secured to the original transistor, noticed that the other channel was also fluctuating a bit and very unsteady so replaced that SV04F also, but now the bias only goes to max of about 2mA with the trim pot, the other channel is the same, so the SV04, 3 diodes in series is causing this, as the good channel (fluctuating) on was able to bias higher with old SV04F....does anyone know which resistors I need to up in size or lower in size to compensate please ? Thanks in advance

supernet · 2021-11-29 1:57 pm

I have for sale new, unused amplifier case. Outer dimensions are: 240(width)x270(depth)x126(height) mm. Internal dimensions are: 195(W)x260(D)x111(H) mm. Weight: cca 3,7 kg.

Price: SOLD

caraudioguy2100 · 2022-05-31 6:58 pm

Amp is in over current mode when trying to power up .

all outputs test fine . I don’t see anything physically damaged and everything I’m checking checks good .

Any Ideas ?

soulmusic · 2022-04-15 12:25 pm

I used to have the impression that bigger subs are always better, I would rather buy a big sub and play it in low volume than playing a small sub at full volume but I read somewhere, don't remember where, that subs need to be bought according to room size - getting a bigger sub than needed will mean it will sound good outside the room, not inside. Is this legit and if so can someone clarify or explain the science behind it?

SoftspeakerCrossunder · 2022-06-01 12:50 am

Hi everyone.
I acquired a super-rare NIB un-assembled Heathkit AA-21 amplifier that I just finished assembling moments ago. Being that the kit is so old (even though the box was still sealed), I used new electrolytic capacitors and 1% metal film resistors instead of the originals. I didn't want to chance using the 50+ year old electrolytic caps and carbon resistors that were in the box.

Anyway, I haven't plugged it in yet because the pre-power-on resistance checks are...WRONG.
Resistance measurements at all the test points on the power transistors and in the power supply circuit are all high, and sometimes double what Heathkit says it should be. The instructions say +-20% or don't plug it in.

So my question is this...
It makes perfect sense that if the resistance checks were low, that could indicate a partial or full short resulting in a catastrophic situation.
But what if the resistance checks are high? Is it safe to power up with a variac and a dim bulb tester, or am I going to destroy the germanium transistors in the process?

Thank you in advance for any assistance you care to offer!

Gene

Flaxxer · 2022-05-31 11:42 pm

Help me understand why powered bass bins with xovers, is not the ultimate end to floorstanding speakers. It allows a person to build as many 2 way tops with any multitude of drivers, and swap out the tops to have different floor standing speakers on tap. A great driver sound characteristics learning tool. What am I missing?

4KAOss · 2022-05-29 3:04 am

I see many schematics that describe multiple resistors in the circuit - as a example 2 @ 8 ohms but they dont state if the are to be wired in series or Parallel is there a standard that applies - as - always in series or the opposite Parallel ? this is for a crossover thanks in advance

wolf_teeth · 2022-05-31 2:21 am

https://www.dejohnfuneral.com/james-jim-smolik/

I noticed someone saying the owner of ERSE had passed, and i went to look for Jim's obit on google. I did not know him other than the rep for the company, and he was always pleasant to deal with for me.

Apparently the business will close for good.

Booger weldz · 2022-06-01 2:26 am

How do you like to exit? Straight out the end or one last wall to encounter prior?

Sometimes it seems each of these folds is an LP filter at the ‘end point’.

Might be more evidence if they’re all precisely on point (this one is off just a little bit in the transition from second to the third segment as it sneaks by the width of the first(Nickel and dime stuff but it all adds up (or doesn’t essentially)?

3d rendering🙁I snatched Carlos’ drawing from his thread).

rhempz01 · 2018-08-12 4:56 pm

I just started to rebuild the power supply in a Rubicon 2500.1 and I found a burnt resistor. R8 anyone know the value of the resistor that belongs here?

JackArmstrong · 2022-05-31 7:20 pm

Hello

i was hoping to make some horns for these precision devices

PD.615C002

https://www.precision-devices.com/products/all-products/pd-615c002/. there are a few.

unfortunately there are a few Thiele-Small parameters not available required by hornresp for modeling a horn.

i was just wondering if anyone could help? is there a way of getting around this? has anyone measured this driver?

hollowboy · 2022-04-01 8:19 am

I'm after recommendations for HF drivers. This is for low power, off grid use, just for me, for fairly close listening (i.e. not for gigs).

System will be run off battery + chip amps, X-over will hybrid active and passive (miniDSP) - so I can apply EQ pretty easily. Most of my listening will be < 1 watt.

EDIT> the intention is to keep the electronics simple: 1 miniDSP, 2 amps. My default would be to have the LF/mid crossover active, and the mid/HF crossover passive <EDIT

My test rig has:

2x15"< 300Hz (12dB crossover)
6" mid on fairly big 2" horn 300Hz-1kHz (no crossover)
Dayton D250P-8 on fairly big expo horn >1kHz (12dB passive crossover)
...and I rather like it. I'm interested in trying something similar-but-better for the HF

EDIT> Picture of test rig added. I listen to the test rig very close, about 1m. It sounded better after I recessed the LF box by about 15cm relative to the horn mouths, but I have the mid & LF mouths on the same plane (despite the mid horn being longer).

The intent for the final build is to soffit mount. When I do that I could physically recess the LF component by slot mounting the woofers, or I could use digital delay. <EDIT

Smooth is good (hence interested in polyimide or similar). Reasonably priced is good.
It doesn't have to go all the way to 20kHz, or be super efficient (the Dayton unit is only 104dB).

My default would be the B&C DE250 or DE500 because Dr Geddes regularly used them as low as 1kHz.

...but I was considering the newer style annular diaphragm drivers,e.g.

Eminence N151M-8 because:

a) Patrick Bateman liked it and tested his with a 600Hz crossover - "I don't think it will have any issue doing 1khz on a decently large waveguide."
b) it measures well: https://audioxpress.com/article/test-bench-eminence-n151m-8-1-compression-driver
c) the annular claim of having a better / cleaner acoustic path is intriguing

Secondary query: assuming low power and a horn that supports a low cutoff, what drivers are NOT usable to 1kHz?

e.g. the cheap driver I'm using has a 44mm voice coil, power rating of 60watts and it works OK with a 1kHz cross.
--> Would any driver with 44mm voice coil and 60watts rating be just as happy at 1kHz?
--> The Eminence N151M-8 has a 38mm voice coil, smaller diaphragm, and is rated for 45watts but (according to PB) is still fine at 1kHz ...and PB kinda thrashes his gear. So that makes me wonder if any driver with a 38mm or greater voice coil would be OK.

limono · 2022-05-30 12:52 pm

Encouraged, by a spectacular success of my Jutland Dennark purchase via this forum I wonder if I can repeat the experience. Reward and opportunity to listen to a nice mini monitors just for handing the box to fedex/ups and naturally handling " the money "

Flaxxer · 2022-05-25 11:10 pm

For midbass in two way speakers? I'm already deciding between these for the Hiq tweeters in Carreras. I decided they are good enough, they deserve better xover components. But are these also suggested for the Rev 5.5 woofers? Thank you

Highcurrent · 2017-02-03 9:18 pm

Hello. Hopefully I'm not being redundant with this post. I set out to replace the non-polar electrolytics in my Goldi's expecting an easy task, but I'm dealing with capacitors here, and I've learned this never cut and dry.

(please refer to the attached photo/diagrams)

* The photo is of the actual crossover. The diagrams are derived from previous posts on this site and are of the standard Gold, not Goldi, crossover. The two crossovers are slightly different, but doesn't affect the job of changing the bi-polar electrolytics,they are of the same value.

-Old caps to replace: Hanlan bipolar 100uf 100v
-My choices for new:
*Elna RBD100uf 100vdc
*Audio Note Kaisei 100uf 100vdc
*Mundorf (raw) 100uf 100vdc
QUESTION...the voltage ratings on the new cap prospects show "vdc". Are these caps intended solely for amps/outputs and not crossovers? And is "vdc" equivalent to the standard "v" stamped on many caps?
Basically, I'm out to replace the bipolar caps in my +20 year old speakers with something that might be considered an improvement. I'm having a maddening time replacing apples with apples while improving the x-over also.

Any recommendations to replace these would be great. I have to believe there are hundreds, if not thousands, of these classics that could use some refurbishing of this sort, so I hope this post/responses may clarify this task for others...

Notes: As for the 1.5uf 100v, and 10uf 100v to be replaced, I've ordered the same value/type caps from Parts Express (bennic?) I could'nt find any other types matching the specs.

And, in reference to the small purple .47uf polystyrene cap shown in the "high" section, this will be replaced with a Clarity ESA .47 250v.

I will most likely keep the ERO 4uf caps in place in the "high" section. The small blue cap "?" in parallel with these has unknown values at this point.

...sorry for any lack of clarity here, and if any jargon I used sounds strange, I'm semi noob at this... Jon

wasabii · 2022-05-21 11:44 pm

I thought someone might have details for these and parameters. I'm curious if they would work good in subwoofer boxes?

vanakaru · 2022-05-31 5:55 pm

I have powered subwoofer with mono line in. I want to use headphone output to get signal to sub. This way the sub would correspond to the vol. level of the amp. Headphone jack is without muting switch. I want to get combined LR signal to the sub without loosing stereo on speakers. If I just connect headphone L&R channels together speakers would be connected the same way playing mono.
What is the way to do this?

IWC Doppel · 2022-05-22 2:43 pm

These were truly outstanding in a different league to 99% of what was at Munich this year. Anyone know anything about how these ribbons work. I always quite liked Apogees and had a pair of maggies a long time ago. The only full range lacking nothing panels I’ve ever heard

SRMcGee · 2022-05-31 8:17 pm

Folks:

In case you're interested, I've started a group buy for balanced toroids in the Group Buys area (https://www.diyaudio.com/community/threads/balanced-toroid-group-buy.386798/).

Regards.

Sonogasm · 2022-05-30 11:48 am

Hi there I have an old Acurus DIA-100 amp I'd like refurbished and upgraded... my hands don't work anymore due to neuro disease, so I'm hoping to find a UK based guru to help with this?

Mike_d_s · 2022-05-26 6:03 am

SOLD

I did a teardown on a Parasound 5125 to repurpose the case for an Icepower project. To cut down on the weight I pulled both toroids. During the teardown I actually figured out the amp had 4 bad channels and one good one. Removed the 4 bad channels and the amp worked fine and both toroids seemed to be working fine with the correct voltages. I dropped one on accident and cracked the epoxy pretty bad but I still have this one which is in great condition. I don't ever see myself using it and figure someone could get some use out of it.
Check the pics for the label details.

$10 + shipping.

Jaroslavius · 2022-05-26 5:48 pm

hello colleagues. A few days ago I bought my first turntable. Grundig PS 2500. Everything was fine until I saw that the needle was covered in dust. I touched my finger and the needle was gone. The AT71 cartridge is there. the question whether to buy an AT71 cartridge and that's it. will it be possible to change to another no. orthophone? worth investing what is the best way to clean the needle?

peterjohnswindley · 2022-05-31 1:37 pm

Hi there,

My question is, can a dedicated mid range driver be used in an infinite baffle to good effect?

Specifically, I have a number of B&C 6PEV13.

And also, given I’d be wanting to cross them at about 300/400hz, what sort of dimensions would the baffle have to be to serve as ‘infinite’.

thanks!

disturbedfuel15 · 2022-05-31 3:40 pm

Hello,

I am located in Michigan, United States. I am looking to either DIY or buy a Hypex Ncore 8 channel amp. I've already built a 3 channel nc400 amp for LCR but now I want to continue on with the rest of the speakers. I don't want the 125w modules, 250w min please.

Thank you much!

avelasco · 2021-10-31 8:59 pm

Hi, I'm a computer engineer, I'm not a analog audio electronics expert but I'm some kind of DIY audiophile

I had this idea running in my head for a while, The things that I would like to have in the PCB was:
1. Space to use film capacitors and mica on audio path
2. Good filter capacitors on power secction
3. The best power supply
4. .1% Metal Film resistors

I know that many persons don't think capacitors and resitors make a difference in sound, but I do and for me is important.

So I ask for your help reviewing this design, I'm open to your suggestions in order to have a better design. I hope you can help me, this is my first PBC design 🙂

iceguan · 2018-12-13 11:25 am

I am building my first 1969 PA from scratch. Instead of using 2N3055, I select MJL3281AG from ON as the output transistors. Before building the Amp, I simulate the circuit by means of Multisim 14.0.

Due to the lack of basic knowledge, I am not able to figure out the functionalities of every R and C in the circuit. Therefore, in order to minimize the THD (measured by Multisim), I adjust the R and C again and again. However, this is definitely not a good solution.

I post here to hope if anyone could tell me the functionalities of the circuit. Here is my circuit.

(see attachment if the image is broken.)

Let me explain the modifications:

1. Change to 2N3906/2N3904/MJL3281AG because they are in production.
2. Change C4 and C5 to larger one to extend low audio frequency.
3. Change C3 to larger one because larger one seems to give lower THD measured in Multisim, expecially in low audio frequency range.
4. Change input capacitor C1 to larger one for Bode compensate introduced by large C4 and C5.
5. Add C6 to avoid high frequency instability.
6. Change almost every R base on THD measurement 🙁.

My concern is:

1. 2N3904 is 650 mW max. Using 2N3904 is not safe here (now, P = 300 mW). However, changing 2N3904 to other NPN parts gives some larger THD. (now is 0.01%, after changing, it increases to 0.03% @ 1kHz) Any advice?

2. Feedback resistor R7 and R8 is much smaller than that in the original design (2.7k and 220 respectively). Changing to larger R7 and R8 (while keeping their relative value) gives larger THD, but why?

3. R5 and R6 are small resistors in value. Are they thermal stable. How about the Q-point stability?

4. R9 is changed to small 120 (original is 2.2k) to lower the static current passing through MJL3281AG. But is it still thermal stable? I don't know its functionality. 🙁

5. Any bad effect when changing C1, C3 and C4 to larger one? One of the bad effect is C4 need more time to charge and discharge.

My final goal is to build 1969 using parts in production.

I really appreciate your help!
Best,

Guan

delverboy · 2022-05-31 12:08 pm

I'm recapping the crossovers in my old AR58s' and don't understand what the 1ohm/100uf across the woofer does. Wouldn't anything above 1.6Hz just bypass the woofer?

Sjef · 2021-02-07 11:50 pm

Maybe this is covered before but search did not come up with anything.

In my experience with various kinds of dsp crossovers with various kinds of volume controls I have come to te repetitve conclusion that in my case, as I often listen to levels at -65dB at night to -10dB occasionally at daytime full digital volume control isn't working.

I have tried digital volume control of Roon, digital volume control of a ESS9028Pro dac, digital volume control of a Wolfson dac and various other dacs of which I don't know the chipset. All work fine up to a cetain point (around -30dB) where they start loosing dyamics and detail. This never happened with any form of analog volume control I have used. What the cause of this is is not intersting to me, the fact that it has been repetetive so far is reason enough for me to be looking for a 8 channel volume control.

Besides, and maybe even more important, having an 8 channel volume control gives me the ultimate freedom of using whatever DAC, combination of DAC's, dsp processors, PC crossovers, soundcards or whatever in front of it because the biggest hurdle of all, volume control, has been covered.

My ideal volume control would have the following parameters.

1) 8 channels ganged that can be used either balanced or unbalanced
2) Remote controlled
3) Volume leveling preset per channel
4) if needed buffered outputs

Is there anything like this in existance? If so, I'd like to know it?
Anyone know of any designs, complete kits or a complete device?

SimontY · 2008-11-25 1:36 pm

Hi all,

Nobody seems to have written an awful lot about this decent old (1986 design) Philips model, so I will.

I bought a CD650 via Ebay for about £10 or so a while back. I can't remember why I bought it but as my main cd player is out of action at the moment I've been listening to it.

It uses the famous TDA1541 DAC and has the immediately familiar character of solid, chunky, warm goodness heard in other TDA1541 designs. The only problem is a lack of detail, a slightly woolly bass and very poor treble.

I popped the lid last night and had a look inside. In particular I noticed:

* TDA1541 PSU lines are decoupled by tiny 47u caps
* Op-amps are NE5532
* Op-amp psu caps are more of the same 47u Nichicon poop
* Signal goes through electrolytics and muting transistors
* The chassis is plastic :dead:

I warmed my iron, cleaned off some of the dust and had an initial tinker.

I made the following changes:

* -15V decoupling cap on DAC changed to 2200uF / 25V Panasonic FC
* -5V decoupling cap on DAC changed to 4700uF / 6V Pana FC
* +5V decoupling cap on DAC changed to 220uF / 35V Elna Cerafine
* DC blocking / signal caps cut out and shorted with a solder blob

This has livened the player up a lot. The bass is tighter, the treble less dirty and veiled, imaging is better and the soundstage is more layered. The good qualities of the player don't appear to have been adversely affected.

More to come soon.

Simon

Soldermizer · 2022-05-29 1:34 am

Amusing "stereophonic" exercise I discovered while trying to remove ear wax. As described below, it didn't seem to loosen the wax, but produced an enjoyable effervescence.

Ingredients:

1 cotton ball
Regular (3%) Hydrogen Peroxide (Some sites recommend dilute 1/2 with water, but this is for ear drops. I have had no ill effect from using 3%) Usual disclaimer: do your own research and I assume no responsibility.

tear off a small amount of cotton and form into a small plug that will fit into each ear. Soak each with peroxide and insert gently. Try to not puncture your ear drum, which would make it hard to enjoy the effect. It should not be a big risk with something as sharp as a wad of cotton.

Sit in a quiet room and enjoy the show for several minutes. Recreational drugs (optional) may enhance the effect.

Spudgunn · 2022-05-31 11:07 am

Hi everyone I'm currently having a problem with an apd15 forseti amp, does anybody know what transistor q7 in the power section should be and how its wired ? This amp came to me with its main fuse blown, I have replaced q7 br3 the zeners on the protect board and the caps on the protect board, the amp section is running fine however the voltage that supplies the front panel controls Is missing and at the moment comes from the emitter of q7, someone else has been in this before me and no schematics are available can anyone help ? I can draw up a rough drawing of how it's currently connected and post photos etc
Thanks in advance !

stereohifi · 2016-12-22 5:50 pm

Hi
I'm looking for modifying a Rogue Audio M120 magnums monblocks from autobias to fixed bias.
Up to now i succeed to have separate bias supply for biasing a quad of EL34 or KT88.
Driver stage remains the same 12AX7 input and two 12AU7 mu-follower.
All voltages are present and stable and no smoke or bang!
I can follow signal amplification from input to 12AX7 both phases outputs to 12AU7 all fine, signal in the range of 20vp-p at 400Hz.
This signal drives output stage in each grid of EL34 or KT88.
Output tubes have 10 ohms cathode resistors without bypass capacitors and 470ohms grid resistors plates are direct to output transformer at B+ 500Vdc.
Problem is from driver stage to input grids.Driver tubes signal is dropped.
Signal with 2ch scope shows coupling caps in at let's say 10vp-p but dies down to 0,5vp-p on the other side of coupling caps??
I have replaced original coupling caps from 2,7uF 400V to 0,47uF/630V to check if this is an impedance problem?
Same, no amplification, with or without power tubes inserted??

Pin 5 grids of all power tubes measure very high with ohmmeter.

Does anyone have M120schematics or M150 ??
I've asked Rogue Audio, of course they don't have it claiming they lost the computer where the designs were..... well if you work on a design, you have it in your head especially this type of amplifier....
BTW this amp works in autobias with 660ohms cathode resistors on each power tubes....... lots of heat wasted there and hi-current in the PC boards makes it problematic,....

qILE2BYsylJiDhQ844DCxC9Z4xS8qbqDiMA5lQTKsfHVyiNzhpS4MsCUUtUUe3ylsdUIQwgWkDw5gHiERgZcLbT0CSPNDKshPyKZ48WIWQA2qbhIuIGpDYAIoI6RSHOUZ0QBQQh46NCgDJufBU+m1MAzhtakJVVIgKnlYxgiLICQ0Yo50bxghCabdFDIAGeUc0scM3iz1CVbvHLNF0XAIIklSEAUEAA7

Thanks
Season's Greetings

c03ePdZ6dNWXn2LsXk74anjn58+fNo19PPjZ68KHRi59PMCAAOw==

sarathssca · 2022-04-19 5:38 am

For sale a pair of (1 set) Alpair 7p speake drivers. I am from Chennai, India.
These were hardly used for few min to check the sound. Could not build the enclosures planned for them, for very long time. Attached the picture of it. On one of the driver there is minor dent caused by kids finger.
Rs. 6000 (INR) for the set.
Thanks.

MarcelvdG · 2022-05-31 7:00 am

Hi all,

Last Saturday, Rewind started a most interesting thread about alternatives to mica insulators. He is interested in alternatives because a part of the mica is produced by child labour.

Later that day, the entire thread had disappeared. I thought at first that it might have been done by the moderation team, but rereading the forum rules, it became quite clear he hadn't violated a single one of them. Rewind also hadn't been contacted by any moderators, in fact he was as surprised as I was about the thread's disappearance.

Therefore, logically, it has to be some odd bug that causes entire threads to vanish.

Best regards,
MarcelvdG

Geotkost · 2019-05-23 11:24 pm

Hello Gurus of the sound,
I would like to know if any of you have experience with using the Monacor SPH 250TC as a bass driver. SPH-250TC
In my opinion, this is quite dated but good driver. However, it is devalued and the information about it is rather scarce.
The projects I saw on the internet this driver is mainly used as a subwoofer, but I don't see a reason why it shouldn't be crossed at around 400 Hertz?.
The concept is a MTMWW speaker
My idea is to use two drivers in parallel of each channel, with voice coils wired in series. 100l BR enclosure tuned at 28Hz should give output at f3 42Hz
Has anyone measured the frequency response and the distortion levels in the 100 to 800 Hz range?
Thank you in advance for your opinion.
Regards, Georgi

wuffwaff · 2011-10-26 9:46 am

Hi,

my old Kenwood CS4025 scope gave up last week. After searching for a while (which is quite difficult without a scope) I think the hybrid ic KMA01 is faulty. I looks like there are two opamps, a small cap, a fet or transistor and a resistor on it.
The simplest thing would be to get a new (used) one. The alternative would be to build a new one.

Does anyone know where to get a new one?
Does anyone have a schematic of the KMA01?

Thanks,

William

ElliJ · 2022-05-28 12:26 pm

My QUAD 405-1 sounds great but when I measured the distortion there is a lot of noise on both channels. What is the cause?

invaderzim · 2021-10-04 12:25 am

Anyone have experience buying direct from erse audio's site? On my current build that will cut the crossover costs in half from what I've priced elsewhere.

Product quality? 10W resistors, PulseX capacitors, 18ga EQ-Perfect Lay inductors.

thanks for any input.

#60619 · 2019-09-03 9:13 am

Hello to all,

Anybody out there that had contact with the UESUGI tube amps from Japan?

Some of the products:

UESUGI 製品一覧ウエスギ/上杉研究所

You can find others on same japanese audio stores only, I did not understood if this are vintage amps, or still in production, not found consistent infos... almost no info in english, for what I found, they are "were" supplied as kits or assembled... appears to be very popular in Japan

The looks is somehow vintage, but you find a lot of images of then, where it's clearly new units.. very clean....

They don't have an official website neither..

Appreciate very much more infos about UESUGI amps.

Many thanks, best regards.

gghodg · 2022-05-31 2:59 am

Hi All,
Ideally KOA Speer CFPS1/4 series 3 or 6mm in length. I only need 1-2 of each but can buy in bulk.
Thanks

No longer needed. Stackpole Electronics Inc CFM series resistors are alternates and in stock. These are "flame-retardant" according to the
UL-94V-0 standard. Interesting note: KOA Speer CFP series are "flame-proof", also according to UL-94V-0.

efm7 · 2022-05-27 7:04 pm

Hi, in general terms (I don't have a schematic) what variables need to change in an amp originally designed for a 12AU7, utilizing both triodes per channel, to accommodate higher gain preamp tubes?

Would it just be a matter of changing the cathode resistors?

Context:
I'm trying to build an amp to accommodate as many preamp tubes as possible (by setting jumpers). it seems like the only cheap 12AU7 alternative is the russian 6H8C, i've even considered quad 6C4, 7AU7 etc.. but seems like those are quite valuable. I'd like to be able to drop in things like a 6n2 or 6n1 since these things seems to be cheap and plentiful for now.

Edit: I should add - ignoring heater voltage and pin configuration as these are more obvious

Mjimenez · 2022-05-25 1:54 pm

What's up friends? this time i am trying to repair and understand how this amp works. He is a Dx1000.1 kicker. My problem is in PS and in the output stage, to begin with I don't know what waves I should see in the PS stage, I understand that the uc3843b is the one that handles the PS pulses, but I don't see anything, just some very scattered peaks and I only have 1 mosfet of this stage in good condition, can it be tested with only 1 mosfet? Are there replacements for these? as they are expensive. What happens if I put them on and they burn again? What signals should I observe in the uc3843b?... Greetings

tvrgeek · 2022-02-17 6:33 pm

Wondering if anyone has changed the input and the feedback cap to modify an AB amplifier to be a second order high pass.
It would look very easy to change to a 70 Hz. Any down sides? Phase problems? Stability problems?

Then with the built in crossover of a sub plate, you are all set.

Sonogasm · 2022-05-29 2:26 pm

Hi there community, relative noob here. I have built a few simple items in the past (few speaker kits, cables, some class d stuff, etc) but came down with neurological disease that has basically made my hands useless for small electronic projects. My much beloved dia-100 mk1 has some serious channel drift and sounds real dark (caps suspected). I have learned the mkII is improved and I would like to bring it up to mkII or preferably much better performance. I'm hoping to find some help in figuring out what actually might be best to do but... ALSO looking for anyone in the UK that might feel able to help me to do this work as I simply cant. Anybody in the UK that can help? I can't walk much anymore so I'm at home all the time and listening to music is the only thing I have left so any help greatly, greatly appreciated. Thanks for reading and all the best folks!

Sadface · 2022-05-28 10:08 am

G'day Guys,

How large an electrolytic cap can be placed at the output of a 7812 regulator?

The datasheet suggets 0.1uF ceramic cap but I would have envisaged something larger: 100-470uF.

The use case is to drive some EC2-12NU, 12vdc small signal relays for a source selector.

Looks like the brand supplied at my local brick and mortar retailer is National semiconductor.

speaker dave · 2022-05-27 7:48 pm

I'm installing ARTA to for a general purpose response tester and distortion analyzer. I picked up a behringer 202HD and have the software working through it but it seems like the inbuilt generator is acting flakey, Definitely not as I would expect it to operate.

The primary issue is that the generators don't turn on when measurements are called for. For some modes (such as SPA spectrum analyzer) I can get the chosen oscillator to turn on by toggling it off then back on. That is, if I am set to use periodic noise and I push the red measure button, the software toggles both the Start Rec and the Start Gen buttons to the alternate state. The highlighted buttons are now Stop Rec and Stop Gen, implying that the generator is on. It is not. I can however, "turn the oscillator off" and back on and then will see the expected signal.

If I am in the IMP (impulse mode) I can get a normal measurement with Sweep only. If I try periodic noise or MLS I see no signal and the measurement is just noise floor 120 dB or so down. I can turn on the generator manually by pushing the generator button on the impulse data panel but it still doesn't come on unless I go to the output volume selector and drop down and chose any volume number other than current (for example 1 dB lower or 1 dB higher) At that point the source comes on and I can see signal in the green bar graph. This still doesn't allow a measurement with MLS or periodic noise because the generator turns itself off when I push the record button.

I'm a long time user of a variety of hardware and software FFTs and don't think I am just pushing the wrong buttons.

Gremlins in the machine?

MatM · 2022-05-28 10:18 pm

This is a subject I tend to rotate round to every few years. The latest spark is becasue I've just spent the day restoring a couple of old 1970's Rotel amps. Unfortuately one is looking positively past its sell-by date, which always begs the question "why don't I put something funky into it". Power amp replacements are straight forward, preamp replacements are more tricky. Anyway...

What I'm think of is a modern, practical pre-amp which has:

volume control
source select
line-level inputs
option for front-panel control or remote control
both digital and analogue inputs
option for RIAA/phono

I'm not talking about audio-purism here: it needs to be practical, usable and affordable.

QUESTION: Am I covering old ground here?

Using semiconductor volume controls and source-selects gets rid of exotic pots/switches and also allows remote operation. No obsure components which can't be bought for Digikey/Mouser. Almost certainly require a microcontroller to handle the interfaces, but thats pretty straight forward (my posion is TI's MSP430's - I've already done a remote control interface for one using an AppleTV remote - very obtainable). The question is then to handle the rest of the system?

THOUGHTS?

There is one option which would make for a very simple circuit, but I suspect I may be burned as witch for even suggesting it: using an Audio Codec chip and 'normalising' everything into digital for processing!!! Something like the Cirrus CS4245: it'll take 6 Analogue Inputs (line level), 1 Digital Input, level balance, volume balance, mute and protect. The only issue is that the audio will be chopped into 24bit/192kbps then reconvertered

6x Line In >> CS4245 >> Audio Out
1x SPDIF Rx >>
Remote/Front Panel >> uC ^

To my mind, thats a 3 chip solution (Codec, uC and SPDIF Reciever) to cover some very substantial functionality

IS THIS MADNESS?

Just collecting ideas and thoughts. If I pursue this through, does it value anyone else?

Mat

Oppenheimer · 2022-05-30 2:36 pm

Hello all,

When dealing with older amplifiers, 20 y.o. plus, should you replace all of the electrolytic capacitors?

I am really talking about for personal use, one you just acquired and have no history on, but is working fine or one were possibly you find a bad cap or two.

If it was a customer's amplifier, is it prudent to suggest recapping?

patchoncas · 2022-04-29 4:03 pm

Hello,

I have for sale the following:
1. 10x ULN2803LW - 15€
2. 5x MCP23008 - 8€
3. 3x Celduc D31A5100 reed relay 12V - 5€
4. 2x Panasonic TQ2-5V signal relay - 6€
5. 5x Zettler AZ850-12V signal relay - 10€
6. 2x pairs Switchcraft connector 8 poles (male + female) - SOLD
7. Omron G6KU-2F-Y-TR4 DC4.5 signal relay - 65€ for all, 5€ each
8. Cirrus CS8416 S/PDIF receiver and mux - 5€
9. AMB Epsilon 12 headphone DC protection circuit PCB - SOLD
10. Variety of black aluminum knobs:
2x smooth with white marker W=28mm H=25mm - 6€ each
1x smooth W=28mm H=16mm - 6€
4x smooth W=20mm H=15mm - 5€ each
1x knurled W=20mm H=14mm - 4€
3x knurled with white marker W=12mm H=13mm - 3€

All prices are without shipping!

Please check all the photos, and if you have any doubts or questions, just ask.

Disco-Pete · 2022-05-22 6:13 pm

The two that top it off for me are The Beatles' build up to 'The End' on Abbey Road and Fleetwood Mac's 'Angel' at the end sung by Stevie Nicks. Both ultimate examples. I want to compile a list with all the best ones. Add yours if you please.

patchoncas · 2022-04-29 12:01 pm

Hello,

Currently selling a stack made of the AMB Gamma 2 and the Objective 2 amplifier (the Stack Squared?)

The AMD Gamma 2 was built to spec following AMB's site and is using a Gamma 1 F (Full++) configuration. This means that inside the Gamma 2 enclosure there's:
USB, coax and S/PDIF inputs (selectable) and coax and S/PDIF outputs
USB to coax/S/PDIF converter
One WM8501 DAC that can receive up to 24bit 96kHz (analog output 1)
One WM8741 DAC that can receive up to 24bit 192kHz (analog output 2)
Digital filter selector
The first output can be used to drive headphone directly. The second output is of higher quality and is meant to be used to feed an amp. The DAC will be shipped with dust covers for the RCAs.

More at:
The γ2 compact high performance DAC

The O2 is the usual suspect, but this one is wired and has panels for being used as a desktop amp:
6.35mm output jack
Input RCAs and output RCAs
No batteries

A power supply will be included for the amplifier. For the DAC, you can power it directly from USB, or use a 5V 300mA power supply.

I am asking for 190€ plus shipping for everything, or 160€ for the DAC and 50€ for the amplifier.

Pictures below (white credit-sized card for size comparison):

Xpandsound · 2022-05-30 6:35 pm

Hey Folks,

Looking to buy some Vintage Jensen 123-S output traffos (steel laminations).

Please hit me up at x.pandsound@gmail.com if you have any 👍

Doghouse Riley · 2022-05-21 3:18 pm

Listening to this from 1974 for the first time in decades, it struck me how "non-PC" some of the lyrics would now appear to some contemporary listeners. But I like it, sad she died in 2020.

"Folks hoping you'd turn out cool,
but they had to take you out of school,
you're a little bit touched, you know, Angie Baby."

///

"It's so nice to be insane,
no one asks you to explain,
radio by your side, Angie baby."

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Of course there's some contemporary parallels to the situation of the girl.

Today the radio can be replaced by the "smart phone,"

"Imaginary partners" can be replaced by internet contacts, many of whom might as well be "imaginary," as they can appear to be, whatever they choose to be.

mattstat · 2022-05-29 5:51 pm

Overview of some of the higher end rooms in Munich. A few things they discuss fit in the planar/exotic category.

Video is about 1 hour and 15 minutes long. Equipment discussions start about 10 minutes into video.

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They cover more brands than this, but here are a few highlight images:

Monitor Audio Concept 50

Audionec Evo

Alsyvox

Aries Cerat Aurora

Borresen

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For Sale London UK: Several European radio triodes REN904 types, AC2 types etc. Great drivers for 2a3/300b etc

WTB quality 15VAC 100VA+ transformer

For Sale Mark audio super pensils

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PD.615C002​

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PD.615C002