Hi,

Is "Harmonic Bass Alignment" in TAS5825 same as missing fundamental based bass harmonic synthesis?

Datasheet does not mention clearly https://www.ti.com/lit/an/slaa786a/slaa786a.pdf

Thanks and Regards,
WonderfulAudio

I was wondering if it is possible (and not extremely complicated) to build a pre amp that could be switched from a normal pre amp with gain to a simple buffer depending on the amplifier its feeding.

So my interest was sparked by this AES paper: Improving Loudspeaker Transient Response with Digital Signal Processing. It deals with designing specific FIR filters, they call them Preconditioning filters. The idea is that you can correct certain aspects of your speaker that are not dependant on listening position (this is a vastly oversimplified explanation). This should be especially of interest for compression drivers and horn resonances but might apply to other stuff as well:


The only thing that the paper actually does not tell us is how these filers are actually created. So that's where you guys come in. How do you think this can be done by the average DIY'er?

New user here so be gentle. I own a pair of B&W Speakers that I inherited from a late friend who was a serious audiophile however this pair have a little bit of a "history" as they are quite genuine speakers that were in I believe B&W's acoustic test chamber (so no serial numbers) and were obtained for my late friend by a B&W engineer who the last time I heard anything of was living in Toulouse and fitting the electronics into Airbus A380's.

This morning one of the speakers failed, I had been doing some work fitting some external fans onto the amplifier as it was running hot. Since then, dead speaker. I took it apart earlier and its a DM2A Issue 2 circuit board, checked some of the circuit diagrams on here and thought the culprit was the 10 ohm resistor at R1 had got hot and failed as I could see heat damage on the circuit board. However once I removed the R1 resistor and tested it on the multimeter it was reading just about a perfect 10 ohms.

I have attached some images of the board apologies if I have used the wrong image host for here, however I'm no audiophile nor an expert on speakers and I am quite stuck to diagnose the issue here so any suggestions or pointers very much welcome.

I'm looking at a Zed Audio Gladius that won't power up. Its using a TL494. Board is mostly SMD components but looks fairly classic AB style, like a Gen X or Nakamichi etc.

TL494
1: 0.015
2: 4.66
3: 0.061
4: 0.436
5: 1.506
6: 3.514
7: 0
8: 0.070
9: 0
10: 0
11: 0.008
12: 13.48
13: 5.01
14: 5.01
15: 5.01
16: 0.254

Photo coming next since this might be fairly new Zed and kind of rare?

Sold

I have a pair of Sovtek 2a3 tubes I purchased from another member some years ago and never used. I’ve tested them and one tests strong and one tests lower but still good. 76 and 62 on a scale from 1 to 100 with 46 being the lower end of good.
$25.00 usd for the pair plus shipping. Assume $15.00 shipping in the states.
Thanks,
Evan

In this video, Amir of Audio Science Review (ASR) explains his past career and what led to the formation of ASR. He also explains the testing process of electronics and speakers using his $200k of measurement equipment.

What is Audio Science Review? | Amir of Audio Science Review Explains - YouTube

Hi
Due to number of Distortion Analyzers with me, I have decided to Part with this good ShibaSoku Audio Analyzer. This has special Distortion hormonic analyzer which will help identify the multiple hormonic content directly. It has good Oscillator close to -110dB THD
Checked two channels whether they output Sinewave and their distortion using AP System 2 - looks alright but one can tweak / or improve. Already one post here describes this Analyzer strength and weakness
Contact me using IM for quote. Equipment is heavy and shipping costs based on this and I am yet to check possible costs. I would prefer selling it to US /Canada buyer for ease of shipping but will not mind shipping off outside

thanks for looking
kannan
Item Location is Austin TX

Just wanted to report I ordered two PP output transformers from Toroidy in Poland and shipping to the states worked out to $84. Not bad when you factor in their great prices to begin with. For reference Edcor (a US company) charges $50 for shipping one small transformer.

$99 or best offer

Can't upload pics

Back in 2017 EVE got originally developed as a quick and dirty solution to add servo bass functionality to an ADAM A7 monitor in conjunction with a StarBass IV accelerometer equipped woofer. EVE 2020.0 basically follows an identical setup with the quick and dirty parts removed and has been optimized using input from this diyaudio thread to improve both its performance as well as its ease of implementation.

EVE schematics:


PCB layout, board dimensions 50x50mm:


PCB top component layer


PCB bottom component layer - names:


PCB bottom component layer - values:


StarBass V accelerometer:


StarBass ClingOn accelerometer:

For availability of both StarBass accelerometers and bare EVE pcb's please see the manual :

https://piratelogic.nl/data/docs/products/eve/piratelogic.eve.2020.0.manual.en.pdf

DIYaudio build threads:

1. MFB for ACI SV12 Drivers using Piratelogic Electronics

Hi,

As in the subject lines I am looking for a suitable replacement for 2N4392, if there is one.

TIA for any help

The ZCA has this strange cult following. I think its great. If people are building DIY audio-Yes its great. The ZCA has proved very, very popular but the pressure was applied to come-up with something else. To have a new ZCA or something very similar.

As far as I am concerned a Zero Component Amplifier has one active component. That is ground Zero. Though not an improved ZCA I do offer for your enjoyment the MCA. The Minimum Component Amplifier can have more than one active component but must strive to keep active component count down. In the MCA the PS and bias networks are unchanged but the power Fet (2SK1058) is replaced by a bipolar.

Part of the ZCA/MAC philosophy is to strive to keep component count to a minimum but also to use "off-the-shelf" parts. The bipolar, which is the heart of the MCA is a 2N3055. But the soul of the MCA is a jFet, 2SK170. Keeping the PS and biasing ccts. the same we replace one power Fet with a Darlington pair of jFet and bipolar. This allows me to bias the 2N3055 correctly and give the amp the benefit of a bipolar output. I like the sound.


The transistor runs quiet cool and and so does the jFet. The load Rs get hot. The power is down to 1.2W RMS but the frequency range is <10hz -3db >125kHz. Strictly using the schematic below with a dead quiet 24V PS will produce a lightning fast, simple SS amp with as much punch and slam as 1.2W will incur. The 100hz, 1Khz and 10Khz SQR wave signals into 8.2 ohms (resistive) are excellent particularly the 1Khz SQR wave. This amp out performs the ZCA many times. Still only two caps in the signal path.


Be the first to build a fully fleshed-out MCA.

The Audison SR1DK had 4 IRFP4232 mosfets installed in the output section.
Here in DIYaudio was another post with a defect Audison SR1DK which had 4x IRFP264n installed on the output.

The IRFP4232 are very good fets (300v and 117A, RDS 30milli-ohm), but unfortunately hard to get for me.
The IRFP264N are 250v and 44A.

I have found the IRFP4332 (250V and 57A RDS 29milli-ohm).
They are more easy to drive since the input capacitance is lower then the IRFP4232.

Does anybody know if the IRFP4332 is a good alternative for an Audison SR1DK?

Hi
For sale, fully functional, original heatsink with all (special) powertransistors and cables, for Kenwood Basic M2 (1984)
Got 2, rebuild mine in 2010 with DRM Audio parts, but they were working perfectly before rebuild.
PM me when interested. Can send pics.
Cheers, Tojoko.

Amp will power up and idle perfectly .

Problem is there is 115 volts of dc measured directly across the speaker terminals .

I tested the outputs in the board none are shorted .

Haven’t pulled them yet to check for leakage .

Any ideas what might cause this amp to have full rail voltage across the speaker terminals?

I may have to try this new DAC for Rasp. Pi or Tinker Board. I wonder if it is microphonic?

DACBerry NTB - OSA Electronics

I've been into DIY audio for more than 35 years and its time to give something back to the community...
You're free to use the provided information for your own personal projects but not for any commercial business.

For the fun of it I made myself an everyday control unit...

Highlights

1. B1 rev 2
2. MUSES 72320 volume
3. Relay based input
4. SilentSwitcher power supply
5. Hypex voltage regulators
6. LED dot matrix display
7. Arduino microcontroller
8. Apple remote control
9. Open source code
10. Case for the control unit.

A YouTube video as a teaser can be seen here.


Let's dive deeper into each area mentioned above:

1. B1 rev 2
I designed by own printed circuit board with the following features:

• Optional input and output coupling capacitors (on board bypass jumpers)
• Optional MUSES 72320 volume
• DC-adjustment
• Prepared for use of (Hypex) voltage regulators
• Prepared for use of the brilliant SilentSwitcher.

I'll later provide the PCB files for production and recommend a PCB manufacture that works for me.
(I've a few boards available, send me PM, first come, first served.)

More info about the B1 rev 2 can be found here.


2. MUSES72320 electronic volume
The volume control is based on NJR MUSES 72320
Passlabs use this as volume control in their top preamp(s?).
As Passlabs I only use the first attenuator and I've no buffer in front so the impedance of the input is in the range of 14-20 KOhm according to the datasheet.

The schematic and PCB layout will follow in a later post...

I'll also provide the PCB files for production and recommend a PCB manufacture that works for me.
(I've a few boards available, send me PM, first come, first served.)


3. Relay based input
Samuel Groner and Bruno Putzeys published a short article with measurements in Linear Audio Vol 13. The article can be bought online here.

After I read the article I couldn't chose any other relay than what Bruno Putzeys use in the mola-mola products... 🙄


4. SilentSwitcher power supply
A brilliant low-noise DC-DC voltage regulator designed by Jan Didden. I use it for everything possible even for my Well Tempered Amadeus turntable!
There's a diyaudio thread about the SilentSwitcher here.
You can buy the SilentSwitcher in the diyaudio store here.


5. Hypex voltage regulators
The original SilentSwitcher outputs +/-15 Volt and I had to lower that a bit and I chose the low-drop out regulators from Hypex.

My PCB for the B1 is designed with Kelvin sense connections to provide point-of-load (local) regulation without requiring physical proximity of the Hypex regulators.
You're can also use ordinary 3-pin voltage regulators or chose the SilentSwitcher MKII that can be customized to output +/-12 Volt and skip the extra voltage regulators.


6. LED dot matrix display
I chose a LED dot matrix display as they're readable on distance even in very bright light. The drawback is switching noise from the multiplexer has to be handled.

To keep things as simple as possible I chose a display kit from Adafruit:

Adafruit 0.8" 8x16 LED Matrix FeatherWing Display Kit - Red

And to make the mounting of display easy I chose to solder some short female headers on the microcontroller board:

Short Feather Headers Kit - 12-pin and 16-pin Female Header Set


7. Arduino microcontroller
The microcontroller is an Adafruit Feather 328P - Atmega328P 3.3V @8 MHz.
USD 12.50... what not to like? 😀


8. Apple remote control
The control unit is remotely controlled by an Apple Remote

I just love the small Apple aluminium remote. I also use it for my main preamp (Vacuum State RTP3D) and my friend and fellow diyaudio member Fonnesbek made the c code for it at the time.

Most of the code for the Apple remote in my control unit discussed here is based on the code made by hifiduino. I just made it work on the Arduino. I might publish the Arduino code itself on Github.

I made the code for auto-pairing the Apple remote to the control unit so where would be no conflicts with other Apple remotes in the same room.
The first time the control unit receives an IR code after powering up that specific Apple remote is locked to the control unit.
The pairing is lost when the microcontroller loose its power. A clever move if you think a little about it.


9. Open source code
Beware that I'm not educated in programming so ugly hacks is to easily found in my code. That said I find the code bug free and highly usable.

I'll make my source code available on GitHub in the near future.
You're free to modify and fork it into your own edition when credited to me (and including 'hifiduino' for his code used for the Apple remote).

The source code shall remain open source and may not be used for any commercial products what so ever.


10. Case for the control unit
I use a well known all aluminium case from Hifi2000 in Italy.

• Hifi2000 Galaxy Maggiorato GX288 230 x 280 mm, all panels are aluminium
• Hifi2000 Galaxy Maggiorato 10mm front panel, black
• Custom CNC machined panels: front, back and bottom
• Discrete text on the front panel (black in-fill color)
• Easy readable text on the back panel (white in-fill color)
• 1 mm clear pipe for the red LED on the front panel.
• All metal work made by a professional company in Germany to my specifications.
• Red perspex is press fit into the front panel.

I'll provide the CNC files that are needed to modify the original hifi2000 case.

--
More information to follow in the days to come.

If any of the provided information is faulty or can be optimised for an even better end user experience feel free to post your comments.

Hello dear members,

First of all, I want to apologize for my English
I live in France and I restore vintage HIFI for many years (for my own)
(Here are some Youtube links🙂
YouTube
YouTube
YouTube
YouTube

I had the opportunity to buy recently in Japan an Accuphase P-300S
I have already restored an Accuphase P-300 but the version "S" is different
I can not find anywhere the schématics and service manual on the internet (for adjustment points, BIAS, DC offset etc ...)
Please, can someone help me?
with many thanks

Alain

For the CD35-X from Grundig it is easy to find a service-manual.
Who can upload this manual from the model "CD-35" without "X" ?
Picture No. 3 shows the "X" version
Thank you very much.
Schematics from Philips models CD-150 and CD-160 are not helpful, because the user processor isn't a MAB8441P T018.

After repairing a chinese audio system for a customer, I copied the diagram for the amplifier section which seemed so easy and single to me that I wanted to build one for my home. This amplifier does not pretend to be hi-fi or high quality therefore I built it keeping the same circuits as the original one. I know several circuits are missing to improve this amplifier but I wanted it to be as cheap as possible. I upload two photos and the diagram. The Amplifier is being supplied with +/-25V, cuasicomplementary output using TIP41C and it really sounds very well.

double PA310 "XKi" in a Karlsonator 12 sized box

dunno how close a BP sim comes

almost bet there's some high velocity wind from the upper area of the slot

box volumes in sketch are for Kappa12a

sim is 2pi 33V

I would like to significantly improve on the 12v wall wart power supply that came with a stand alone t/t motor.
Any suggestions ??.

Personal 4 way active build all scanspeak
First items to arrive
4 x 11inch scanspeak woofers

Hi folks


I just bought a power amp and there is brown gunk surrounding the base of all four smoothing caps (two per channel) so I think it's wise to replace them, especially as they are Jamicons and are probably of dubious quality anyways.


Here's the circuit they are in, they are 2200uF 63V units.





I have some ELNA 10000uF 63v caps I would use, but they are too big to physically fit.


The only other large value caps I have that would physically fit are some 6800uF Dubiliers but they are only rated for 35V.


What voltage rating would replacement caps have to be - 63V or would 50V suffice?


Is there an advantage to using larger values than the 2200uF it has installed?

I wanted good speakers, but couldn't find any that fit exactly what I wanted. So I started looking up today how to make my own. This led to me trying to discover what method of cabinet would give me the best quality audio for my driver. This in turn led to me finding this video: World's Second Best Speakers! - YouTube

This vid taught me a lot: wavelengths, construction and deconstruction, porting transmission and horns. From there, I decided to keep reading, which is how I discovered BIB, folded horn, backloaded horns, and a few others.

The main things I took from the video:
- having your two soundwaves exist together at matching wavelengths by measuring the deconstruction and construction of your driver and designing a "tube" at a certain length for it to pass through.
- Using curved aluminum sealed with DB dampening glue to plywood helps increase the quality of the sound as it travels through the "tube"
- What materials should be used in constrained layer damping (in the vid he outlines how to make it better than just MDF)

Here are my questions:
- I have seen people state that the open fiber-filled top design of the Voigt is not necessary. After researching a lot of contemporary designs this seems to be true, as nearly none of them have included it, but I'm unsure why. I believe the BIB does not use an open top design. Could someone help explain?
- I read that the human ear picks up the most discrepancies between 20 and 300hz. Is this true?
- If so, I have also read the the Voigt lessens quality in low frequency sounds because of how it exits through the bottom.
- I have read that many drivers are not designed for a Voigt cabinet style, but I am unsure of what I should be looking for under specs of a driver to determine what cabinet type would best suit it.

All of this is the basis of my understanding so far. I have done around 7 hours of research today, and I just started on this project. I was considering using a design with the voigt or BIB, but using curved aluminum in a pattern similar to that of a turbo for a car (or the golden ratio) to amplify the sound as it leaves negating the decrease in quality of frequencies between 20 and 300 hz.

You guys are the kick *** dudes that I've been reading from the past 7 hours, so I made an account to hopefully have you guys help me in my quest to create a kick-*** audio cabinet system!

(PS GM you are a legend.)

I built the parts-express 8" sealed sub in their .75 cf box. Being small and sealed it takes a quite a bit of power, but it is for a small system in a small room and it does sound good with a 100 watt amp for that situation.

The problem I'm running into is when I stream music through jazzradio.com; during the quiet parts, between the songs, the driver flops around making a motorboating sound. It doesn't do it when I pause the playback or between songs on other sources.

Both of the subwoofer amps I have top out at 100 watts, one is a class D OSD amp and the other is an A/B dayton plate amp. To get the right level of bass they have to be turned up quite a bit but sound perfect during the music.

Obviously, there is something in the source that is causing the problem but my 2 store bought subwoofers, that don't need the volume cranked as high, don't make any noticeable sound between the songs, when swapped into this system.

The question is: Do you think this an issue that is only being made audible by pushing the 100 watt amps to the edge of their capabilities? I hate to buy a 250-300 watt amp and have the same issue.

The title was changed from "System Pictures & Description" to "System Pictures & Description / Subwoofer Gallery". This began when there was some uncertainty, and an alternate thread was being used.. but it was thought that the thread might better serve if its purpose were more clear to everyone.

All systems are still welcome, subwoofer or not.

I recently acquired all the transformers (and choke) from a Heathkit Apache TX-1 Transmitter.

Specs for all transformers below.

Part #: 54-65 - Power Transformer (P: 115V; S: 600V@175mA CT w/ 2 Taps @ 240V@20mA, 6.3V@9A, 6.3V@3.5A, 5V@4A, 5V@2A)

Part #: 54-30 - Plate Transformer (P: 115V; S: 1800V@400mA CT)

Part #: 46-10 - Choke 5.5H 400mA (38 Ohms)

I can't make up my mind on what to with them. One thought was that I could make a nice variable HV tube bench supply but I would hate to waste them if I could build nice tube amp. The transformers look really nice and need to be shown off.

Another thought is to build a 845 SE amp. With the 1800V CT txfr, I could get around 1050-1150 volts on the plate and use the other 54-65 transformer to power the driver tubes.

Either way, I could build one heck of a boat anchor/space heater with these transformers. I also have the option of purchasing a matching set from the same guy I bought them from. Maybe 845 SE monoblocks? 🙂

Any ideas would be appreciated!

I'll kick it off...

First time experience of a tube having a dry joint - an old radio valve where the heater had stopped working. Seller suggested re-soldering the pins and indeed that restored continuity. I've never had this problem before. Now I know.

How common is this, and have you experienced similar issues?

Please post digital amps (with inbuilt dsp for audio filtering) that are still active.
Like
TAS5707 :- https://www.ti.com/lit/pdf/slos556
TAS5706 :- https://www.ti.com/lit/pdf/slos550
BTW, the above chip are "Not Recommended For New Designs" as per TI

hello ,

i need some help to try fiwing a mrvt505 amp;
sudenly stop working
open it : Q503 and Q504 are blown, all pins shorts.
so remove them, and replace
Q503 was readable : irfz44 but not Q504
Q505 and Q506 just near them are all irfz44
so i replace both with irfz44n
no shorts then
so i plug it in the car and mosfet blown again !

what can i check please ? (no other part seems burnt)
thank you

So I've salvaged two 350 VA 26-0-26 Vac transformers from two defunct German Leslie clones that had two power amplifiers each.
Now I'm thinking of re-using the two power transformers. As supply rails of +/-35 Vdc yield to just moderate output power and don't utilise the trannies' full power capacity, I'm thinking of connecting the secondaries in series to get rails of +/-70 and +/-35 Vdc and building a stereo pack of class g or class h amplifiers. Are there any designs that are worth building?
And what's the best PSU configuration? Should I stack four 10 to 22 mF/50V 'lyrics in series, or is it preferable to have a separate grounded 'lytic for each of the four rails?
Best regards!

Anyone in knowing of transistor with higher than average Veb that's 5 v for most power transistors? And found Veb to be a decisive factor in at least one scheme? Using 1300x series with Veb 9v but they are for different purposes primarily and not good sonic response. Thanks in advance for your understanding 🙂

This thread was split from another. Split begins here.


you may have a build up of carbonate down in those grooves. Usually the carbonate is the highest at the lead in groove, but sometimes there are excessive amounts towards the label. Try super cleaning that record and see if it helps. Few vinyl collectors know much about carbonate, but the vinyl is loaded with it. Not easy to remove but once you do, your vinyl will sound so much more open, and natural sounding.

I have recently been made aware of this dual channel FFT software, similar in concept to SMAART Live and SYStune.

Sound measurement application for tuning audio systems in real-time
by Pavel Smokotnin

RTA, magnitude, phase and impulse response, coherence, group delay

Open Sound Meter

So far I have only done some loopback tests on a 2i2 3rd gen, looks like a great addition to the toolbox 🙂

Only mention of it I can find on DIYAudio is somewhat hidden here:

Active DSP: Please post your software and equipment

This little Xtant is in line to get its vaccination.

Received this amp with blown IRFZ44 power fets x4. There is no pre-driver circuit in this amp after the SG3525 so I replaced the 44s with new, and lowered the original gate resistors which were smoked looking 47ohms down to 22 ohms.

Amp powers up now and plays fine on the LEFT channel, but the RIGHT channel I get no audio. Rail +- looks good as does regulated voltage to all of the opamps. I pulled some kinda crossover module out and just used standard jumpers in its place which is a thing with Xtant. Looked like a high-pass module?

Anyway, I traced an audio signal from right RCAs through the opamps and across the jumpers, but I'm a bit lost after that. Theres a full monty of TO92s on this amp, and SMD stuff to boot.

A schematic would be helpful if anyone has one. Anybody happen to have one or anything come to mind?

I am looking for recommendations on a significantly improved phono preamp kit for my analog system. The sonic performance is currently really quite good: full bass, good separation and sound stage, and very realistic. Would I be better with a solid state or tube preamp.
(1) Lenco L-75 turntable modified with a custom plinth and Silver Note 512S tone arm. Stanton 681 cartridge with a Pickering 625DJ stylus. I would like the option of upgrade to a moving coil cartridge in the future.
(2) Hagerman, Bugle 2 phono pre-amp
(3) Bottlehead Stereomour 2A3 SE tube amp
(4) Klipsch KLF-20 horn speakers (100dB/m)

Below is a list of the phono pre-amp kits I have found.
(1) RJM, Emerald (RJM Audio)
(2) Elliot, P06 HiFi Phono Preamp (Hi-Fi RIAA Phono Preamp)
(3) Tindie, Muffsy Phono Preamp PP-4 Kit (https://www.muffsy.com/muffsy-pp4)
(4) Pass Labs, Pearl 2 (https://www.passdiy.com/pdf/PEARL 2.pdf)
(5) Signal Transfer, Phono Preamplifier (The Signal Transfer Company: RIAA PCB with unbalanced outputs)
(6) Boozhound, Deluxe Phono Preamp (https://boozhoundlabs.com/collections/all/products/deluxe-phono-peramplifier)
(7) Tavish, Vintage 6SL7 Phono Stage (https://tavishdesign.com/products/vintage-6sl7-phono-stage?variant=13907030662)
(8) GlassWare, Aikido Tetra (https://glass-ware.stores.yahoo.net/tetrasansps.html)
(9) Bottlehead Reduction 1.1 (https://bottlehead.com/product/reduction-1-1-phono-preamplifier-kit/#)
(10) Bottlehead Eros 2 (https://bottlehead.com/product/eros-2-phono-preamplifier-kit/)

Thanks!

Hello all!

I have been working for awhile on this.

I know its not as ideal as some of you guys would like it to be.

But I tried, and it's my FIRST build ever.

Took nearly a month.

I didn't have the foam of 5/8" that is recommended by Zaph, waiting for that, till then I just used a polyfill sheet I had lying around to cover up a bit.

Haven't heard them properly as they have not been placed yet, but overall, very pleased. The highs feel a little pushed back to me for some reason, but that's because I am probably used to my other bookshelves I am using as a surround now.

Lou Ottens obituary: cassette tape inventor dies at 94 – Legacy.com
Lou Ottens eho invented the compact cassette has died. He was 94.Mr. Ottens made a huge impact on the worlds of audio and music.

I tried a Maplin Millenium 4-20 clone build but failed.

These are professionally manufactured clone boards.

A copy of the original article will be provided.

On offer are the two clone PCBs mounted onto a 3mm aluminum chassis.

You get the 2 x PCBs fully populated + the 8 x valve sockets. Nothing else.

The chassis was drilled to accept 2 x Hammond 1650H and a single 250VA toroid, these are NOT supplied.

I'll attach photos of the project. The valves (EL34, EF86 and ECC83) have been removed. The transformers and input / output / mains components have been removed. All you will receive is the chassis with the 2 x PCBs and all the valve sockets.

I don't want to throw it in the rubbish if someone can use it.

These are close clones of the original Maplin PCBs.

If you want the woodwork, please ask.

FREE to a good home, you only pay postage.

2 EXO-050 SINGLE-ENDED PARALLEL FEED (PARAFEED) OUTPUT TRANSFORMER NICKEL LAMS
Plus 2 Magnequest BAC-100 Plate chokes
These are around 10 years old.
Used only one in a mono amp. Insulated the covers on this one, grounding them for lower noise.
The other is unused.
Nickle lams
Retails for $325 ea
ALL yours for $325 plus ship
by Paypal only


Magnequest Products - MQ Iron Listing/Pricing




2 Magnequest BAC-100

Special made. 100MA
Top cover is drilled out on one because of chassis wiring layout. Used. Covers are isolated from core and bolts too for lower noise floor. Ground at star ground, isolate choke off metal chassis with plastic bolts.
One in unopened plastic is unused.

[/IMG]

A few years ago I purchased Sony VFETs, I have now 6N and 8P. Then I've have read on Papa’s article from 2014 where we can read about CSX1:

"Ah yes, the sound. Well, it's different. A lot of clarity without annoyance. For a little amplifier it holds up well at your higher volume levels, and certainly doesn't get harsh with abuse, and is better than a lot of my other little amplifiers at complex symphonic pieces, probably due to the largely third harmonic character. It is very non-fatiguing, the kind of piece that makes you go through most of your record collection."


That sounds delicious! It is actually what I am looking for. I am happy with F2J which has 2nd dominant harmonics, this one is more into the 3rd.

Now I am not trying to be a smartass… 🙂

My understanding why Mr. Pass used transformers in CSX1 and CSX2 is:

• Use of simpler and cheaper PSU that makes life easier for DIYiers
• Possibility of using balanced input
• Floating input hence no ground loops
• Signal on the amplifier output is not inverted.

Because:

1. Transformers might have (or rather have) some impact on the signal
2. As a result of the electromagnetic field radiation from PSU transformer they may introduce a hum
3. I appreciate the minimalist approach 🙂
4. I believe the transformers are not absolutely essential (same phase on the both VFET gates)

...I came up with an idea of removing them from the circuit.

I am not trying to say that they are not necessary but for me personally I would sleep better not having them in the signal path (also having just a bit of the ego tickling having own(ish) design) I thought it could be a bit of mine till I found Zen V5... well… that was at least a confirmation that it wasn’t foolish of me to remove the transformers from the circuit. As Zen Mod pointed out this design is more prone to the PSU ripple. But using the PSU circuit from the Zen V5 I got -109dBFS 100Hz at 1W 8 Ohm 1kHz on the simulation, comparing to -93dBFS on the CSX1 with a "smaller" PSU.


So the rest of the measurements from the simulation are:


Total Harmonic Distortion(1W, 8Ohm, 1kHz): 0.090558%, 2nd -99dBFS, 3rd: -60dBFS
Frequency response: 1.5Hz - >1MHz @ -1dB
Gain (1W, 8 Ohm, 1kHz): 2.8x
Output impedance: 4.16 Ohm


Without the buffer on the input I am getting up to 89kHz at -3dB (1kOhm source), hence the buffer.


Since Zen Mod banned me for disliking transformers 😀 I have to ask others for their opinions:

Am I risking anything here starting the project and not adding the transformers here?

Is there anything I am missing here/not seeing the problem?

Do you think it's worth trying?

Any ideas to change/improve something?

FS: Red Baron V5 TDA1541A populated boards.

As the title says, I'm selling one or two of my Red Baron V5 boards fully populated (0.1% resistors or for the 2K2 's ,handmatched to less than that).

Film capacitors are Wima and BC Vishay(MKP).
The 1N4148 are also tightly matched.

One board is with a genuine TDA1541A(Holco resistors), the other is without the TDA1541A(Vishay Roederstein resistors).

I'm open to reasonable offers. Payment will be PayPal family and friends or you pay the fees. Shipping will be at actual cost. I'm not interested in trades.

Edit: If don't know the value of the parts & PCB's, I won't give you a minimum amount I'll let it go for. You give me an offer, then I'll let you know if I can live with it.
I'd rather keep these than sell them for pocket change.

I have a Michaelson and Austin TVA-10 which uses a 36V winding on the transformer for all of the driver tubes' heaters.

The complement is 2 x ECC83 (differential phase splitter), 2 x ECC83 (push pull voltage amplifier) and 2 x ECC81 (push pull bootstrapped driver).

The tubes are heated in 2 strings of 3 tubes.

The issue is that the driver tubes, one in each string in particular, light up like lightbulbs for a couple of seconds when the amp is switched on.

This issue has been discussed on other threads, and the general response is 'do not worry about it', but I will need to replace those tubes soon, and I'd like to ensure the longevity of the replacements.

If one looks at the Philips tube data sheet for the ECC83, it contains the following statement ...
"In case of series supply a current-limiting device must be inserted in the heater circuit for limiting the current when switching on".

I'll look at the specs of inrush current limiters to see if I can match the steady state current (450mA in each string), but this will sap some of the heater supply, which is already a bit lower than spec (36V as opposed to 12.6 x 3 = 37.8V).

Another option would be to rectify the 36V, but that could put some extra burden on the transformer.

Is there a standard current limiting solution in these cases?

Hello,
I have a not bad sound interface (Focusrite Scarlett 2i2), better than sound card normally.
Can I make distorsion measurement with it? Can you guys recommend a PC software for that?
I do not expect 0.000x % THD to be measured, but at least in the x% range?

I want to change components (bias of tube, to improve linearity) and see results immediately. When I see minimum THD, than listen to it.

Thanks,
JG

Anyone heard anything about these yet?

TANG BAND W4-1052SA 4" DRIVER 4 OHM

Parts Express number 264-828

Looks like an interesting design, wish they would post some graphs.

Also did anyone else notice they got rid of the woofer common application chart in the new PE catalog...kinda sucks, because that can help determine whether or not it fits your application.

Maybe a open baffle dipole with two in series...for 8 ohms

Hi there
I am quad-amping and I want to get rid of unnecessary DA- AD-converting in my stereo.
So after doing crossovers staying in the digital domain I gonna need a 8-chanel DAC befor my 4 amplifiers.
I might have the oppertunety to get my hands on a Mytek 8x96 DAC, but I don't know if it is still any good after todays standarts?
How well dos it hold up to lets say a RME aid-8 DS mk iii?

Anny input are welcome 🙂

Hi,

I have an Krell Avangard integrated amplifier, that today works with voltage at 120v and I would like to change it to be able to work at 220 / 230v.

I opened the equipment and saw that there are two switches next to the input fuse, SW1 and SW2, and each switch has two positions 1 or 2, SW1 is in position 2 and SW2 is in position 1.

I would like to confirm that if switching from SW2 to position 2 I would be changing the input voltage to 220 / 230v.

Thanks!!!

Folks:

I placed an order with Newark on March 3, 2021. That order included 49 line items, 9 of which were identified as being "UK Stock." According to Newark's website, all of the items in my order show as being in inventory. Newark's website claims that UK Stock-based items will be shipped to Newark's US facility ("Delivery in 2-4 Business Days") to be added to the line items inventoried in the US and then shipped to the buyer. If only.

It's now 2 weeks later and I've just gotten off a call with Newark's customer service department. They claim that one of the UK Stock items I ordered has been shipped to their US warehouse for forwarding to me (presumably with the 40 line items in their US stock). It is unclear why the other 8 line items in Newark's UK Stock have not shipped. Newark's customer service department cannot explain the cause of the delay; they promised to contact the UK warehouse and email me an update, but I've been down this path before and am not holding my breath.

This isn't the first time Newark has screwed up an order for me or shipped far later than promised. Newark often has items I want at prices that are far lower than Mouser or Digikey, but Newark's shipping delays are both horrible and routine. I don't know if Farnell, Newark's UK affiliate, suffers from the same issues.

Are Arrow or Allied better suppliers? Who are people turning to instead of Newark? I have to find a more reliable, reasonably-priced alternative.

Regards,
Scott

$99 or best offer

I'm starting a new monoblock amplifier build using the Purifi 1et400a module and thought it might be interesting for others to follow along and lend their input. This will be my third pair of monoblock amps built this year, after a pair of F5 Turbo v2 amps and a pair of Neurochrome Mod-286s.

My last exposure to class D was with a pair of Nord Hypex NC500 amps using the Hypex SMPS1200 supply and Nord's rev D input buffers. These amps were quiet, clean, detailed and powerful, but I also thought they sounded kind of flat - I never really had the emotional connection with the music that I do with other amps.

Virtually everything has changed in my system since then, and I've gotten much more into DIY, so I thought I'd give class D another try. But I don't want to just throw a couple of pre-built modules into a box and call it good. So my amps will be a bit different than the norm.

First, I am building these with a big linear power supply. This is partially because I can at least build this myself, but also to see if it has any affect on the way the amp sounds.

I'm also designing the enclosure so that I have room to experiment with different input buffers. I'm going to start with the Neurochrome board to get the amp operational quickly and to have a baseline, but then I plan to build several more designs using custom PCBs. I have enough room for buffer PCBs that are 130mm x 85mm which should allow for a lot of options.

The design approaches I am considering include:

• Simple discrete op-amp design using one Weiss OP2-BP for each balanced leg. This is similar in concept to many of the commercial Hypex and Purifi amps.
  
• Fully balanced design with quality op-amp (such as OPA627) feeding a single-ended class A mosfet buffer for each leg (similar to Whammy design).
  
• Fully discrete line stage with JFET input and MOSFET output stage for each leg (similar to Salas DCG3).
  
• Similar to above with bipolar outputs.
  
• Tube-based design (see this thread - https://www.diyaudio.com/forums/tubes-valves/361030-help-tube-buffer.html).

I'm hoping to do a new input buffer every month or two (the first one will take a while since I'm learning KiCad). This will keep me busy for a while. I'm not sure I'll do all of these, depending on how it goes. If you've got thoughts on what you think might be the most interesting, please chime in.

I've sent the enclosure drawings to Modushop (Slimline 3U/350mm), so hopefully I'll have the enclosures in a few weeks.

I'll make follow-on posts with additional details.

Can’t see using these now that my systems all active. All are used.

North creek 10 awg 1mh $60.00 for the pair

North creek 12 awg .3mh $40.00 for all 4

Jantzen 14 gauge foil 1mh $30.00 for the pair

Goertz 12 gauge foil 1mh $40.00 for the pair

Price is USD shipping not included.
Thanks for looking,
Evan.

Posting this here in case it helps someone else. I recently picked up a decent Denon DP59L but the cover was thrashed. You can buy replacement moulded ones on eBay but at a cost! I wanted just something simple that didn't look completely hideous.

I saw a post elsewhere recommending a company in Germany who makes simple bolt together display cases. The cost is low, the lid pictured here was 38e plus vat. Shipping is cheaper because it's sent (very well packed) flat pack. The pics below show the assembled case, so you can see what it looks like. Not the same as original, but not bad and about a 6th of the cost of a moulded one.

Sora-shop.com is the address you need. Total cost delivered, vat etc was 54e and it took about a week from order to delivery.

Hi,

I've recently acquired a pair of Philips 22RH 426/51Z speakers, from the early '70's I think.
Not much info. about them online, although I did manage to find the service manual. The pdf is too big to attach, but can be found here:

Philips manuals | Hifi Manuals Free: page 13

I'm fairly certain they were never the best speakers available, but they're well made in a charming old school way, and a look inside reveals decent quality components in the crossover.

Any thoughts on what I should do with them?

Thanks,

Matt.

Jfet measurement jig

I am currently matching my jfets using a breadboard. But I wanted to make something more permanent.

The nicest arrangement I found was the one from runoffgroove. It allows idss and Vp measurement.
A closer look at the Fetzer Valve

The 10M used for Vp still allows some current through the jfet, but it should be close enough for matching.

Here is my schematic



And this is the pcb



A jumper or a switch will be used to change between idss and Vp mode.

I will order the pcb on Monday. In the meantime any input is welcome.

I picked up a hurting Lexicon 412 (Bryston 8BST).


Here's a question I submitted to Bryston. What say you?



I hope I haven't broken any rules here.


Hi,
I have tested the main board on my Lexicon 412 for +56/-56V on all 4 locations and the supplies are good. I metered out all the transistors and diodes on the two bad amp modules. All small transistors and diodes look good. I have 3 totally shorted SJ6521A’s and one SJ6522A.

Questions:
1) What is the best replacement for the SJ6521A and SJ6522A?

2) The pre-driver is a MJE15030 an MJE15031 in all 4 channels. Are these the originals or has someone changed them?

3) Because this amp can be bridged several ways should all channels have the same transistors?

4) Can you sell me 3 good used original SJ6521A’s and 1 good used original SJ6522A and a used good heatsink?

5) I will replace the 3 electrolytic caps. I like the low ESR Panasonic “FC” type. Is that the best option?

What do you recommend as the parts are NLA.

Thanks,
Gary Maffei

Hi people, I have this sub, only issue is when I bought it, it had a very loud hum. The previous owner had it repaired which lasted for 8 months odd. I looked inside and caps look normal, no swelling but on the rear side of the only circuit board is a few IC chips, 1 has what looks like a burnt chip, instead of it being black, you can see the metal under that.

Also, whoever repaired it did not bother to secure all 3 cables which has double sided tape on, 1 of which is very close to the live input from the wall socket cable, whether something has touched it, is a possibility.

Can ic chips be scratched, scraped and still work ok?

Other than that it looks ok inside, but worth pulling the main caps out of circuit to test?

Hi there,
I have spent quite some time reading stuff on this forum. Now I’m entering next step and join the party a bit further.

I have a problem I’m sure some of you can help me with. I’m building a 3way speaker. I would like to do a Bi-amp setup and use my old updated HK 680 integrated amp for the bass driver (below 400hz, passive crossover) and plan to use a Musical Paradise MP 301mk3 for Mid/tweeter (400hz and up).
Problem is how to make this work since MP 301 is integrated as well.

Can I simply take Pre-out signal from HK 680 and connect to line-in on MP 301 ?
I fear that setting volume knob on MP301 at 100% will start hum, heat and so on. If this is a bad idea, is it possible to find connexion point to be able to use MP 301 as a poweramp only? If this also is a bad idea, what similar tube poweramps could you recommend ? About same price and powerrange.
It would be nice to start the ”tube rolling” journey.

I’m hoping to use a powerful (John Wright) TL bass in combination with the magic of Tubes for mid and top 😉

Thomas

Hello Everybody

I have been reading tons of stuff about active speakers as I want to build two three-way boxes and one of the questions I have not been able to solve so far is how to effectively protect the costly tweeters from DC-voltages in case of problems.The amps for both midrange and tweeters deliver more than enought output voltage to never go into clipping and are working well below their power ratings so no problems to be expected there.

Everything I have been able to find and read points to no circuit truly being able to protect directly connected tweeters against DC. be it because of time-constant or whatever else any existing circuit is too slow or has other drawbacks.

So my question is what would happen if I simply connect a large coil of say 5 mH across the tweeter and an admittedly slow fuse between the tweeter and the output of the amp which is driven by an active filter of 24 dB and a crossover frequency of 3 KHz.. There should be very little signal ,if any , getting there below 500 HZ so the extra load on the amp caused by this should not be any problem ?
The tweeter-amp runs on the full supply of the bass-amp but needs a fraction of the power so one could use a 4 ohm resistor in series with the tweeter to limit the current required of the amp throught the coil as frequency decreases and adjust the gain accordingly to compensate the lesser volume of the tweeter bringing it back to the correct level. Of course there will be some power lost in the series resistor but I think acceptable if the tweeter is effectively protected.

I would be grateful for any info / explanation as to why or why not.

Looking at the supra 2.0 schematic i had an idea to instead of paralleling the opamps at the input, to parallel them at the output, in a master slave configuration, much like some headphone amps that have been seen on this forum.

Lets say 4 ne5532 per channel, 1 side of the double op used as an input then the remaining 7 paralled as a buffer, then the riaa feedback is global and treats the master+ slave as a single gain stage.

Or we can even split 1 of the 5532 into a 2 stage riaa then the remaining 6 channels into a master + slave buffer for the 2nd gain block of the initial 5532.

I know from experience the master slave config can be made to sound very good as a pre/headphone amp and because like drives like (same slew rate) the oscillation is at low risk.

Id like to know how viable this idea would be tho when its a high gain circuit of phono amp

Deleted Found Solution

Hello, my name is cheapvega and I have a problem with expensive hobbies. Cars, motorcycles, road bikes, sim racing, photography, and of course, audio.

Currently building a system for my kitchen with ceiling hung DML panels and thinking about going OB for a critical listening/quasi HT setup for my living room. I guess I like to "think outside the box" 😀 Looking forward to getting involved here. You guys have a great thing going

Hi Guys,I need your educated opinion preferably based on practical experience-I want to import a power transformer and a Aluminum chassis from India or China to the U.S.A for amplifier project and I'd like to know if there is some kind of customs/taxation on it and if so how is it calculated-much obliged in advance to learn from you all.Also if someone can recommend me on a good shipping company from India or China to the States at a reasonable price-It'll assist me a lot

Amp came in with shorted FETs on 1 side of the PS and 1 bank of the output, see 1st pic. I replaced the known defective parts. The amp powers up and has drive signal on both output sides and they match. The issue is the output under load at the speaker terminal.

With a 40hz signal input, and a 1ohm resistive output load, 1 side(negative terminal) looks like it is shifted slightly from the other, see pic 2 set to DC. The 3rd pic is set to AC for a better view. When the signal volume is increased to a higher level, the output begins to distort and starts drawing excessive current, see 4th pic. This level is well before clipping point. I have set the DC offset with the 1 pot to zero at idle but I'm not sure what that 2nd pot is used for. I adjusted it but didn't see any change, it's back to it's original set point. With the amp running at a low volume and no output distortion for several minutes I see no abnormal heat build up using a thermal camera. Any clues?

I am looking to buy a TP BIIIse Pro. I would prefer the 9028 version.

This project should be placed somewhere between Digital and ChipAmps 😉 It's my new volume control module basing on WM8816 from Wolfson. I call it 'WM STAMP', because executive part of it is very small.

Some details and basic functions:

- gain range from -111.5dB to +15.5dB
- gain step size: 0.5dB or 2.5dB

controls:
- IR remote (program can learn every RC5 remote commands)
- encoder
- standard, analog pot (ADC)

- optoisolation
- LCD or VFD 2x20 display
- backlight adjust

- output for 8 relay selector
- mute
- optional name for every input (like 'CD', 'DVD', 'TUNER', ...)

WM8816 is similar to PGA2310, but... opamps are outside 😉 This give many possibilities:
- many single opamps can be used
- discrete stage
- using some high power opamps we get good, headphone amp

Schematic diagram



I found WM8816 chip in:
Marantz PM-15S1 Reference Series Integrated Stereo Amplifier
Marantz PM-11S1 Reference Series Integrated Stereo Amplifier

Hi I broke my ankle and dislocated my foot so I am down for at least 10 weeks. so I am trying to figure out how to plan my next speaker. I want to downsize the excellent small thors. I already have switched to the nextel drivers and with a lot of help got them working pretty well in the old boxes. I rarely listen to them as they are downstairs and I really want to move the music party upstairs. So this is an opportunity to design and build the boxes. Attempt to mimic the small thor design making it smaller sacrificing bass. I would like to stay with the mltl style but there is very little information on how to do that. the fs is 40 on the woofers and the quarter wave would be just over 84 inches. the thors have a fs of 34 so they need 102 inches so I am pretty sure this will not work but can I change the length of the speaker by 83%? At this time here is my plan


design and build the boxes
use the current crossovers and measure

replace the parts in the crossover to get a slightly decreasing fr.
put is all together and live in musical bliss. here is a rough drawing of my plan for the boxes.

Hi all

I have a cassette stereo from an early 90s Volvo (stereo model TD-603) which I've got working again and now am putting Aux/Bluetooth inputs and removing the cassette player.

So far I've had good results tracing the tracks from the cassette pre-amp to what appears to be an audio processing chip (DIP20 Toshiba TA7764P). I've inserted new audio signal input leads close to the chip, leaving in the caps between signal lead and the chip (2.2uf 50v electrolytics). I cut the tracks near there, removing all the cassette pre-amp circuitry. This seems to work as it should with reasonably clean signal at the right level.

My questions would be...

* Should there be different caps (to the pair of elec. 2.2uf) or any other circuitry before the TA7764P? Both from an audio quality and protection point of view? It's going to have both Aux in, and a Bluetooth unit. I guess the Aux input may need to be a bit resilient because it will take various input devices - eg phones, mp3 players etc with different output levels etc.

* And on the subject of caps - I did have to replace one or two of the large ones - the biggest one had leaked and caused PCB damage. The circuit board is full of electrolytic caps (40 odd). If it was only a handful I might consider re-capping just to re-furb a 30-year-old device, but is there any in particular caps that would be a worthwhile swap? And if so, should I replace any with Tantalum or like-for-like LESR caps - or so-called 'audio' caps? (Without wishing to start a bar-room fight).

* I've read that it's good to short/ground unused audio inputs, to remove unwanted noise - but is it always the case? I am nervous about shorting anything! So should the Aux jack socket be shorted when there's no input (given it's in a car)? The 1/8" socket unit I have has extra pairs of pins that short when there's no jack in, giving that option. And - the Bluetooth unit I ordered (when it arrives) has an Aux input, which gets over-ridden when Bluetooth is active - is it OK to have a shorted Aux input into that, if I use that?

* The power supply for the Bluetooth unit: It hasn't arrive yet, but just to get it ready (the BT unit takes 5v-32v): I have a 7805 and a B0505S DC-DC isolator (incase it needs that). What would be the advisable circuit component sequence here, combining the 7805 and B0505S plus caps?
With caps, in the datasheets the B0505S specs 4.7uf in 10uf out. For 78XX it's 0.33uf in 0.1uf out.

Thanks for looking at this.

Cheers
Jim

Thought that I should report my latest fun with the "big-rig".

Uncoiled a "2mm square" (14AWG?) inductor and cut it in 1.2 meter lengths. Connected these bare/naked copper foil/ribbons to my speakers and experienced the best sounding cables so far in my book.

I have not done any A/B tests yet but will do soon.

Earlier I have tried Red Dawn, $1600 AudioQuests and several other cables, these are the best so far. They sound a little cleaner, more resolved than other cables I´ve tried. It´s like the high range is "cleaned up" and also the low level resolution seems to be better in the mids and high´s.

Must compare back and forth a couple of times with the old cables to make sure I´m not fooling myself . But there seems to be a not so small improvement.

It takes 10 minutes to make these cables and a coil is about $15!

My friend with the $1600 Audioquests did sound a little bit worried on the phone when I told him about this cheap, simple solution. 😀

/Peter

Original genuine Honey Badger PC boards (one pair). Unmolested in original bags. $39 plus actual shipping cost.

Too many projects, too little time...

These are currently sold out on the diyaudio.com store, of course.

Hello Guys, I hope you are fine. I upload this diagram concerning to an Class H American Audio amplifier which does not activate the high rail (+/-125V) to the output stage. This amplifier is supplied with +/-63V for low voltage and +/- 125V for high voltage but the man who is checking it out, said that when the volume is turned all way up, five volts are only given to the final stage for both rail. The amplifier sounds good but the output power is lesser than it can deliver. What test do you suggest for this amplifier? Thanks beforehand.

Based on the VH Audio's design, I made a pair of the OCC 5N 28 awg solid core silver cables last week. The results are amazing: open sound stage, airy, focused images and very detailed. I can hear more weak music tones and can now define the "distance between layers of music". 😀 They beat my 3 other diy solid core silver rca cables. 😡















What I'm going to do next? I'll re-do those cables which were twisted conductors in design 😀

I found 4 x "NOS" ILP HCA40 modules.

HCA40 data

Anybody know what they sound like / got experience with them?

Extract from the datasheet:
"The ILP HCA40 audio amplifier module offers the ultimate in high fidelity performance.
The unit, which is strongly biased into class A, exhibits audible smoothness and clarity and has been designed for the ultra high definition perfromance associated with class A operation."

Don't have a PSU at moment to test myself, but sounds interesting.

First off I want to thank everyone ahead of time for their time. I'm no audio or electrical engineer. I'm just a guy that wants to sit down after working the day job and then working on the farm and relax and enjoy some music.

I have dappled over the years and played around with various gear. Recently I liquidated alot of items to just settle on something that I feel I will like. I do enjoy the Dynamics of horns and just bought new two way Jubilee speakers and ordered radian PB950 drivers with beryllium diaphragms.

I'm older so I do have a nice turntable and enjoy vinyl. I also have a DAC2 from benchmark and have about 1tb of music on a hardrive. My other components are a tavish design phono preamp, the dude tube preamp, and I plan to use a citation II on the horns and a classe DR-8 on the bass bins.

So to be honest the active crossover and EQ of all of this will be new to me. I wanted to stay all analogue but looks like if I want everything dialed in right I have to go digital on the front end. This will allow me to crossover around 500hz, EQ, and get the time alignment of everything right. I want to learn more about all of this but between 60 hrs a week and also having cattle, I do not have time to research and learn more. So after some brief reading the DEQX HDP-4 looks like it is the best product on the markets for what I need to do. It does hurt my feeling knowing I will take my vinyl concert it to digital and then back to analogue but I see no way around this.

So is the DEQX the best product for what I'm trying to do? Also is the hardware in this unit some of the best on the market? Obviously I want quality A/D and D/A converters... I can find very little info on what hardware is in their units...

Wondering which microphone and which software are "best in budget" class for eq/room correction. Wondering which pay-for software is good and also which "free" software is also decent. Thank you.