continuation from the previous thread.

A query.
Anyone has used an R-Core transformer?
Just want to know why you use it and where did you get it. Thanx.

salvage it from old R-core Sony CDP..

or contact the designer..

http://www.kitamura-kiden.co.jp/english/index.html

This post has been edited by ar188: Jan 15 2009, 07:38 PM

Thanks for the link. You don't happened to have some loose R-Core in the drawer, no?

no la.. but I got some baluns and ferrite core transformers

I'll make a note!
BTW, your blue LEDs, the small ones.. am gonna use it on my VSPS front panel. Definitely will look super cool!

hehe! 3mm with diffused blue lens.. that should look pretty cool.. remember to drive it below 4v (3-3.5).. or else very fast poof..

Scotty, what about the old thread? It still contains useful informations for newbies.

Very true. Can we have it (compiled) like an FAQ or something?

damn right it is!!
the collection of info since thedoctor era....very2 valuable!

Guys, if u dont mind me interrupting.
How do u cut a say 3 inch hole? I use to DIY myself but the outcome aint always nice. I'm thinking of DIYing a SOHA II but I'm having difficulties drilling 2 holes on the top of the casing for the tubes.

What material are you trying to cut? Steel or aluminium?

A lengthy process, takes bloody much time, but the effort is worth it.

Use masking tape to mask the area you want to drill. Draw a sketch of the circle on it. Proceed by drilling lots of lots of holes using the largest drill bit available exactly within the area to clear it out. File the rest of the tiny bits to get a nice circle. It's time consuming due to the need to drill multiple times.

EDIT: Alternatively, a dremel works with the above method too, except faster.

This post has been edited by LittleGhost: Jan 16 2009, 10:52 PM

can always "pinjam" some one's milling machine..

anyway there is this special adapter to fit to a drillbit..can cut fairly large (inches) circles on metal plates with a electric drill

Steel is a little bit harder though... easier on aluminium..
As per LG's process but I'd drill a series of small holes.. about 1/8" max., very close together. Once completed, 'punch' out the inner metal and use 1/2 round or rat tail file to smoothen the hole and adjust dimensions to suit the object going through the aperture

wei then it'll look very kraftangan effect..

Off course la! Thats what DIY is all about!
You've seen my 'kraftangan what...

That's what I've been doing but the hole aint always beautiful. Since the 2 holes for SOHA II is not hidden, i want it to be as smooth as possible. Any companies in Msia that does this sort of cutting? =)

plenty..but need to pay or maybe they won't want to do one off basic jobs..

Icic, i guess i'll just stick to the conventional style. =)

Anyway, anybody DIYing any new amps at the moment? mind sharing?

There's one thread on GainClones..and T-Amps
I have not started my GC.. waiting for some parts and time...
No more amps for me, too many already!

SOHA II seems to be a good amp to DIY, alot of good reviews about it. Cost about USD225 shipped from glassjar. Anybody got a say on this?

USD225 is way too much for me..especially for a headphone amp!
I think someone did make a SOHA but no idea about SOHA II...
I'd rather spend the money for a good tube pre and tube phono preamp!

This post has been edited by jazzy939: Jan 17 2009, 12:37 AM

SOHA II? luckily not SOHAI?

It would be if you join them together!

Hai guise! Look what I got for free:



Found it on the hallway beside an EE store with other working but unused instruments. Could only cart this benchtop DMM in my backpack. A brown person carrying around something that looks like a bomb in Amerika? Luckily can fit in the bag.

I'll go back there to see if the power supply and signal generator is still around before some bugger picks them up and sells them on ebay.

Wow! An old school benchtop DMM! With a calibration sticker too! Wonder when it was last calibrated?
Good haul Eokboy!

2002, last calibration due 2004

It has 4-terminal resistance measurement I found the manual in pdf too.

I just wonder how good is the shunt regulators used as power supply for opamp/DAC vs the typical LM 3x7 and 78XX series. do u find lots of improvement ?

In another way, how is the MUR 860 with black gate and 7805 compare to the shunt regulator ?

This post has been edited by ccschua: Jan 18 2009, 10:52 PM

^Plus and minus.

In short, shunt regulator has ugly efficiency compared to the series regulator.

In general, shunt is used widely for isolation purposes and for local regulation when the current draw is not too big while series for global regulation (providing a huge block of circuits which draws higher current).

Shunt does have some benefits over series regulator:
1) Protected against input transients (isolation feature)
2) Current output is limited by CCS, thus no explosion due to shorted outputs.
3) To a certain extent's better than the series regulator due to symmetrical current sinking and sourcing.


For your case, you'll do fine with both solutions.

Alternatively, use the super fast Jung Super Regulator to beat the crap out of both solutions.

Switching noise is inevitable especially the gears such as cdp , dac and pre and power amp are all connected to the same source.

The charging of diodes do provide some transients and feeds into the subsequent stage. So for the DAC, switching noise is totally unwanted. Therefore I still think the shunt regulators using fully discrete (no opamp at all ) gives better solution in terms of background noise, and dynamics response.

The guys at diyaudio are coming out with charge transfer regulators which (was used in airline) and to dem the input signals to the NOS tda 1541.

I will learn the crap first before I jump to what solution for the power supply for sensitive application like my TDA 1541 DAc.

This post has been edited by ccschua: Jan 19 2009, 12:02 AM

^switching can be prevented by forcing the regulator output to light Class A.

just wondering why no threads on STK?

how do you do that and with what mod ?

Probably it is because no one is interested in it?
or no one knew about it?
(no advert/publicity)
No fans here lah ar188 except you know who.....

actually, diode transients are negligible if your PSU is done right. Adding the snubber caps already eliminate most of the noises. In addition, your main circuit must have already high PSRR so it does not even matter at all. (if it doesnt have high PSRR it's not worth it anyway)


Sometimes, back EMF can cause the regulator to "momentarily" switch down. If there's enough capacitance on the output, this is usually not an issue. Performance can be further improved by forcing a constant current out of it, e.g. using an LED.

stk sounds good but is this better than CG or T-amp?

Got my parts from amb and the goldpoint is coming. Haha, now just need my 4 casings, 1 for the twin trannies, 1 for the PSU and 1 for each inverse and non-inversed amp stage.

mlm <--- behold my finger of jealousy.



Anyway, I just pulled the trigger on three B22 boards and one s22 board.

Oh noes, sins!!!

'better' is subjective. It is all a matter of preferences, one man's meat is another man's poison.
Between STKs, GCs and T-Amps each have their own strentghs and weaknesses and NOT really the same platform to be compared with.. just a different means of amplification. At the end of the day, let your ears decide!

what does your ears say?

Build some discretes like the Hiraga and let me know if your opinions change.

hope to see the fully discrete amp doing some whacking on the speakers.

18Wrms. Still thinking how to increase it to say 50W unbalance into 8 ohms.

The 40W/Channel discrete..

so T-amp is out?

Not entirely... love listening classicals and vocals on it..

First time etching my own PCB.



EDIT: A JFET based Class A buffer with servo control. Planning to use it for my balanced setup/just stereo buffering.



This post has been edited by LittleGhost: Jan 21 2009, 06:37 PM

Littleghost: Nice job! do share with us ur project progress later

took me 3-4 hours just to get it right O_O"

Semi populated the board. Not sure if i want to heatsink the output transistors and bias them further.

. Lazy, will continue testing and debugging tomorrow.

Just finished soldering in the RN60Ds for my B22. A few values missing, but will arrive on tuesday via FEDEX.

A shit load of caps also arriving from Handmade electronics, Silmics for the amp board and high voltage Nichicon KZs for the PSU board with Wima MKS2s all around, building for high voltage and high gain with 30V +- and a gain of 11. Resistors have been binned and matched for more accuracy too. Goldpoint should be arriving next next week, thus i'm looking forward to getting it. Toroid is custom wound by Tortech Australia and comes with a Mu-Metal casing shield.

Connectors are all 3pin XLR Silver plated Neutrik, why? Found them easy to use and fitting, PSU is a Positive Ground Negative, so i need 3 pins, Input and Outputs are also balanced, so it makes sense. I'm just scared being the klutz i am, i'll plug the PSUs into the inputs

I'm rather worried about case work rather than the amp itself. I've done tons of amps, but this will require a case of ass blasting proportions. Sigh, wish i could pay someone to do all the case work, but all the "handiwork" exihibited by my peers at Uni = worse

How about this AV228, cost effective.

http://www.vt4c.com/shop/program/main.php?...p_id=2&hit_cat=

I actually settled on an ATI Technology full Alu case and a custom designed Front and rear panels with Front Panel Express last night.

Expensive, but if i'm building an awesome amp, might as well go superawesome. Also ordered silicon wipers for the board mounts and connectors, lol dampening. The only thing that is generally mid end is the heatsinking, because sourcing the heatsinks is insane, and because i'm anal when it comes to lead lenght, although i made up by using silver bearing thermal grease. Was thinking of forced induction cooling with a small rear mounted EBM PAPST 60mm fan and seperate PSU, but i'll see if things pan out.

i like this one. good

Shit. Right now i can't remember if the Pin 1 of an XLR connector is connected to metal casing of the plug/socket and thus will mate the ground of the PSU to the socket, which is a huge no no because i wanna keep Signal and Power ground separate, but still be able to use XLR connectors to carry the power from the PSUs.

Anyways, i've already sent in the PSU frontpanels for production, about 160 Dorrars, shipping not included. Which is the shit part because i can't remember the basic XLR contruction

Specs for the PSUs, which should be finished by the end of the month. 1 PSU per 2 channels.

- Schaffner FN9263S PEM Filter
- Tortech Shielded Transformers
- Custom front and back panel plates with relevant markings
- Hammond 1455T2201 casing
- S22 PSU configured for 30V B22 Max
- Neutrik XLR for power umbilical connection
- Silicone washer dampening

i hope my memory kicks in. Been away too long. Will post pics when complete. Also finished CatEgg's M3 today except for the opamps, removed the old socketed 627s (if you're online, MSN me so i can place the order for the right opamps you want) and the heatsink mounting. Also finished the S11 PSU that was built for it. Kewl.

Tested and assembled. Did no hearing test yet, but I'd assume it to be pretty good sounding. Basic Buffer application for pre amps or directly driving headphones. It's ac coupled so sources can do away the output caps.

EDIT: Next thing will be a dual rail PSU and a discrete amplifier

This post has been edited by LittleGhost: Jan 25 2009, 03:57 PM

Just wonder hows the fully differential amps get going, is it musics flowing now ?

How;s the buffer circuit doing ? any diagram.

I am doing some phase lock loop filters for DAC. Wonder what type of capacitor and resistor I should use ? SMD. no way, it is too small for me to see. any suggestion .

This post has been edited by ccschua: Jan 29 2009, 10:32 PM

My lazy ass finished 1 B22 board. OMFG THE RESISTORSSSSSS. I realized that i hate soldering. 3 More to go. Blardy malas, but must to itttttt. Also had some delays due to police work for my firearms lesen and the fact the stupid safe had to be bolted in (Thanks Perry for the save ). Pic of my workbench. And note that the periuk nasi has 2 week old mushy rice in it, don't dare wash it, i blame my housemate.




Working on an M3 too, for KucingTelur. I realized i forgot to install ze output resistors, so i had to remove the FETs .



Worst of all for the B22 is, i was supposed to buy 56.2 Ohm resistors, but then i bought 56.2k Ohm ones. RAGEEEEEEE. Now i must order more from Mouser! Not that i won't, but it's just a hassle and makes me boh song because the amp board is missing 2 resistors.

This post has been edited by empire23: Jan 29 2009, 11:53 PM

wah 1 resistor value order from mouser.. got free shipping from US to auzzie?

No free shipping, going to buy other stuff as well, got a few things on my list like CPF-1 Resistors, some Caddocks and Neutrik plugs.

i really wonder if u r an engineering student. Those are noob mistake. You can talk technical, but i doubt it's accuracy now, hahahaha

Now i should sit back and enjoy my music while u can rant on my post or give me more technical knowledge lecture

This post has been edited by valve_300b: Jan 30 2009, 01:18 AM

Well, we all make mistakes, they're just like typos lol. Hey aren't you they guy with the cheap Nikon who bashes "poor" people who use headphones? I has a D3 and 1Ds Mk III Wanna see?

And yeah, still an engineering student, have moved on to the shit which is post grad. It's more like number crunching these days.

I think i've always made clear that when it comes to building amps, procurement is hardest parts. Hard to get shit sorted out when you're juggling tons of BOMs.

i think you are still too Malaysian or should i say too malay. They just can't take criticism positively.

Just to share with you since I don't think you can figure this out. Ever wonder how does the deaf musican, Beethoven, listen to music? The skin on our body actually has senses. The dynamic and pressure produce by speakers or instrument can actually be picked up by the skin. This is where the realism is.

Read this http://www.sciencedaily.com/releases/2001/...11128035455.htm

Headphone is not able to produce that to be picked up by ur skin. You can categorise me as 'perfectonist'. I'm after the finest art on earth, be it sound re-production or photos. As such, money is not in the picture. If you always wanted to compare the price per performance ratio, you will never get the best because the price can never justify it.

Btw, I think I have more, I have a D3x, A900, 1Ds MK III, H3D you wanna see ? You should try the D3x. Althought some sony fanboy seems to claim D3x uses the same sensor as A900, i don't see A900 coming near D3x.

This post has been edited by valve_300b: Jan 30 2009, 01:56 AM

You even played a musical instrument before lol? Once you have the basics, you can generally put it together in your head. You don't sense music, you think it, notes are written, then played to look for technical viability. Well that's the whole "formal" process behind it.

I like listening with my ears thank you very much, less distance, less distortion, less loss, more sensitivity from headphone drivers, higher impedence for better loading characteristics, and thus, a purer sound in the sense. Wonder why sound engineers use mostly headphones and small driver monitors? So sad. Yeah, maybe i'm the perfectionist here . Sigh, a lack of education, tsk tsk . And wait, those same engineers are the ones who master the CDs you play...ZOMG!

Wait, didn't your posts around here indicate you had a "cheaper" Nikon? Got a gallery i can see?

Anyways, don't want to make too much of an investment on audio or cameras, gotta get a Mannlincher rifle with Schimdt and Bender optics to put with my Remmy.

PS: You shouldn't even be in this thread, you can't even do Thevenin let alone solder without setting yourself on fire hahaha.

This post has been edited by empire23: Jan 30 2009, 02:13 AM

sound engineer use headphone because it's just cheaper and they are not perfectionist which is why i still prefer vinyl ! hahahaha how sure are you all sound engineer uses headphone? The Lucas Art studio i went isn't. They were mounted with JBL speakers earlier, now I think it was replaced by MK speakers.

I beg your pardon ? Is the deaf able to 'know' the high and low notes if u put them on headphone ? The answer is NO.

---

Added on January 30, 2009, 2:22 amsorry i have not set fire soldering my first x-over for DIY speakers, my DIY pre-amp and my DIY amp

at least i can read diagram properly and doesn't forget to solder my components or buy the wrong components...

V=IR works most of the time to me and some basic calculation of serial circuit and parallel is what i really need. And of course differentiating AC and DC

if you get ur design right, i don't see the need of Thevenin Theorem. Perhaps noob will need it cause they might be too good in talking technical but can still get the calculation wrong

This post has been edited by valve_300b: Jan 30 2009, 02:22 AM

Well, it's the sound engineers that use the headphones to tune that sound, and yeah, the sound engineers are the ones that use vinyl too. Lucas Arts makes games lah, what do they have to do with being audiophiles? Lucas Film maybe.....but IIRC they leave their music recordings and mixing to Sony BMG. BTW, you're calling yourself a perfectionist, while you say the people who do this for a living aren't? Zounds....i'll have a few chuckles with the boys at the sound engineering labs and the recording labs on your behalf. Yeah, that's why we spend 5 years to learn stuff, so we can be less perfectionistic than audiophiles

Anyways, yeah, they use speakers, or known as monitors, with low wattage, high sensitivity and small drivers, with a flat frequency response and none of the frequency compensation used by audiophile speakers and they're designed for close distance listening for the least distortion.

Yes, we call those kinds headphones, hearing aids. LOL.

---

Added on January 30, 2009, 2:30 amI want to laugh, but i feel like crying. I feel so sad for you man. Really.

Next you'll be telling me i can throw away by Smith charts to do complex impedence.

You know man, i love you. You're so dumb you make me seem smarter than i actually am.

This post has been edited by empire23: Jan 30 2009, 02:32 AM

I found it to be very little photo when there are quite a number of DIY here.

This post has been edited by Vincent Pang: Jan 30 2009, 02:48 AM

What do you mean?

I lol'd IRL.

Small signal and large signal analysis, hybrid models and such. If your design doesnt revolve around around that, then it has failed.

I dont see the gain from the person who try to or intend to show his mastery of audio. All I hear is distortion.

Guys, let get back to the works from where it began. Hopefully the biasing is not an issue.

XD it will be an issue if he uses the 56.2k Ohm resistors.


The FETs have the best symmetrical swing with 50Ohm loading.

i believe alot of forumers has DIY some amps. But I browse through the 4 pages, there's nothing much except for your Work In Progress photos. I remember seeing some photos on setup for forumers. In V1 maybe?

Not THAT senile YET.

But doing a cursory check, i think i screwed up a few pots. Note to self, don't do work at 3am, it's not good for accuracy.

Now must go beg the evil powers that are for the use of the desoldering machine. Sien when i see that Lec's face, it's like he's constantly pissed off at something.




Alot have DIY amps, very little actually build them, a large majority of them are built by Littleghost, Eokboy, Thedoctor and other forumers and not all post works in progress pics. I generally do so to keep my customers in the loop due to my long building times so they don't say i'm a lazy bustard who only sleep at home (actually i am )

Try the headwize or diyaudio amp builds thread, i go there for my DIY amp picture porn and it teaches you alot of stuff just by looking at pics.

Demanded PICTARS? Request delivered.



This is an amp that i just finished for a forumer. Class A biased Diamond buffers with a dual opamp, plus a mini 12V regulator. Used quality components.




Also, pcb'ed dB3 amplifier (single layer) for prototyping. Etched myself using iron transfer. Planning to go fully factory manufactured PCB after I'm done tweaking it with an OPAMP that would beat even discrete stages.

Capacitance multiplier seems great for isolation but I'm currently thinking of individual shunt regulators per OPAMP for greater isolation.

Just finished populating it last night. Might do some listening tests later after I claim my RM600 for the road tax. lawl.

Here are some other older pictures if anyone of you are interested:




My main amp . AD825 fully Class A amplifier.

This post has been edited by LittleGhost: Jan 30 2009, 11:08 AM

Shunt regulator as in an IC Linear reg per channel? Or a MOSFET as a pass tranny with a feedback opamp?

Lol, anyone putting on a discreet FET reg and cap multiplier would be arsed for board space, and not to mention you'd need a low imp path for the gate control which complicates matters. But nonetheless, it would be awesome. Overkill, but awesome.

As for the dB3, to get an opamp that would beat a discrete would take alot of effort, and you might have to employ compensation to keep the opamp sane if the board isn't small enough. (tip : No sockets lol, gives a bit of leeway)

nay, i'm thinking off simple discrete shunt regulators instead of a single capacitance multiplier. A low noise BZXC series zener diode buffered by a low noise BJT. It really does not take up much space though. More like PPA's isolation JFET plus four more components per channel. IC Linear regs? XD I'd rather do 3 jungs and feed 3 separate channels. However seriously unnecessary lol. I'd be gone with fully discretes if I were to reach that point.

I've been hearing good words on the AD797BRZ (higher grade with very different specs comparing to the ARZ version). However it's bloody hard to implement properly due to it's insane speed. Not to mention input bias is high due to it's BJT input. Planning to build an amp that revolves around that chip and properly bypassed and compensated.


I've had that gut feeling that the Input transistors of the diamond buffer plays the most significant role in that topology. Hence why the use of very high impedance swap mirrors with feedback to load the input transistors. Sounds better than a regular PPA buffer. Thinking of further cascoding the input transistors. I guess I'll have to sim moar to proof that the most significant influence comes from the input transistors.

I wonder how would AD797 fair compare to OPA627. Are they the same class. fast, detail and clean.

not the same class

AD797 is way ahead of the OPA627, specs wise.

Hmm, a Zener and a BJT.... for the same board space but more moar moolah, change BJT with Pass FET, Use zener as VRef add small SOIC error amp. Muahahhahaha, i'm the bad idea fairy and i'm here to dole out stuff to screw up designs

Lol the 797, why do i now sweat thinking of taming it and about the countless hours infront of a PC to optimize the NFB loop length and short bypassing.....mah salutes to you, i for one hate highspeed AD Opamps.

As for the dB's input trannies, i think PPL already made it clear it's a tradeoff between stability and perf. Further cascoding would stabilize it better for more enhancement, but that would also require more matching on your part of the cascode stage itself. Work....more work, i'm allergic to it

This AD797 is interesting. superfast, clean and low noise. but how would it compare to discrete such as OPA Sun V2. opamp cant live up to discrete right.

Not necessarily.

Read the recent review from Majkel? He ranked the AD797 better than the OPAs from Audio-GD.

HDAMs are kinda limited in some area due to space constrains. You cant lay additional parts for it. The AD797 is also an improved folded cascode topology which gives it insanely low distortion. (tip: the extra transistor on the floating mirror ) If you want to beat that you'll have to lay the entire amplifier circuit down instead and use as much performance enhancing designs as possible.

I just read the data sheet.

Reminds me so much of the LM4562. Both are BJT inputs, have great performance and voltage range, but are really b****es to work with.

Not only that. The AD797 hates driving capacitive loads too. Fortunately I'll be using a buffer along with it so it's not really an issue lol.

Just pray that it's not as worse as the AD8397. I don't want to use ferrite beads on mein signal.

I wonder if anyone has AD797 x 4 for loan and test. it looks promising to be used for IV conversion and then buffer output of the TDA 1541a

They don't seem too good for that kind of work man. Just my 2 cents.

A buffer should always be one tough basket that'll drive anything under the blue sky. Buffers are also Unity gain, and unstable amps at unity gain are well....unstable

Try this http://www.national.com/ds/LM/LME49600.pdf

Empire23 is right. It hates driving capacitive loads like I've mentioned earlier. Adding output resistances will counter it but you kinda mess up the whole idea of a buffer (low Zo)

The AD797 is not cost effective. How about giving Amb's Jisbos a try? It's one of the best buffers around.

Well this is my output stage of the TDA1541A. I will implement the DEM reclocking using 352kHz (i.e. remove C19 and add the 352kHz positive and inverting clock as in diyaudio to remove the intermodulation cause by the DA conversion.)

I dont like this output stage as it sounds rather resistricted. further I dont see the recommendation by AD being implemented in this output stage.

Qustion : What is global feedback. Does this output stage have global feedback?

Qujestion 2 : The first 2 NE5534 is IV conversion right? The second is buffering right ?



This post has been edited by ccschua: Feb 1 2009, 10:34 PM

The AD797 is a beast. I doubt the schematic's AD797 is properly implemented.

AD797 requires a lot of effort to tame it down and to sound good.

Q1: yes it does have global feedback. Global feedback generally means the loop encompasses the entire signal path. Feedback point is taken from the end of the output.

Q2:Schematic doesnt show the NE5534

Before you go further. That's a shitload of voltage on the opamp supply rails man

If you ask me, when it comes to DACs, follow what the datasheet says. Because to sell the DACs the Manufacturer has to spec them at high performance levels, and to do that they need very specific circuits, which they almost always include in the Dsheet. The only thing i recommend you tweak aside from simple component replacement (eg; replacing the buffer amp with a dB or JISBOS straight) would be to change the DAC select settings.

Oh yeah, i see DC offset removal caps in the signal path. DO NOT WANT.

Q1 : Oops. That's not what I want. But the global feedback is the easiest to implement. I wonder if people say no global feedback with with proper selection of filters, they are talking about multiple order of filter, perhaps 3rd to 6 order. (why is feedback adding so much odd order harmonix )

Q2. the triangle is the NE5534 single output. It can be directly replaced with AD797. What is recommended in AD797 is this.



DC blocking capacitors in the output is unavoidable as this DAC1541A is output DC coupled.

Isnt that almost always current output DAC such as TDA 1541 uses the IV as first stage and then follow by Buffering for isolation?

This post has been edited by ccschua: Feb 2 2009, 12:11 AM

Feedback is a good thing. But too much is bad. The feedback factor on opamps are generally high due to the very high open loop gain and the not so flat/linear open loop gain/bandwidth.


Another way to counter this is to use jung multiloop so you push the distortions due to feedback out of the audio spectrum.


EDIT: Yes, the TDA is dc coupled. Caps however can be added in between stages for better effect. If the AD797 is stable, you can put a small high quality film cap between the DAC and the buffer instead to get more efficiency and signal quality. Since the input Z of the opamp is high, you don't need an electrolytic.

This post has been edited by LittleGhost: Feb 2 2009, 08:33 AM

Wau. that sound to chim to me.

The circuit i given is from JAPAN TDA1541a circuit mass produced in Hong Kong. So the cmponent values are basically tested for use with those opamp. If I were to place the dc blocking cap between IV and LP stage, that will involve changing the values of the RC circuit righte.

Hay Guis. Just got my SumR trannies. Doesn't come with the pottery case because i felt it didn't look cool enough.

Now due to my pocket being blown to bits by the recession, casing the B22 PSUs will have to wait. Sadly.

The extra tranny is for a S11 powering an M^3 so i figured 20 VA should hold the fort as these trannies are underrated.

---

Added on February 7, 2009, 8:46 pmI just found 4 JISBOS Boards. Anyone want me to try and populate em? Board only. Casing will cost alot extra.

This post has been edited by empire23: Feb 7 2009, 08:46 PM

hi diy amp community,

how about some FET cyclotron, the atom smasher. no. the amp..

http://www.passdiy.com/pdf/Build%20The%20A...0Circlotron.pdf