neutralzz

Looking foward for that..

The simpler the better for beginner like me..

Do like to build a very low cost amp with only SimLim Tower parts..

What is the meaning of POST? Can I use it as a normal headphone amp after a DAC?

Does it involve high voltage(240V or larger than 100V) besides the transformer part?

yes it is operating at 220-300v depending on the transformer you use, that is the only high voltage part but its not much of a hazard if you wire it carefully and accurately.

POST tubes are german tubes that was used for communication back then... and the d3a, c3g series are 3rd generation post tubes, so superbly made that the tubes are self supporting, i.e. mica spacers do not touch glass envelop.. for low noise etc.

yes input is typically RCA so if your DAC output is to normal RCA interconnect, it can be used.

more information here

http://www.jacmusic.com/nos/C3g-C3m-info.html

mind sharing the schematics ? this seems very interesting

ah.. i was going without a schematic actually.. just following the curves on http://www.4tubes.com/DATASHEETS/SCANS-Original/C/

i.e. rk 180 ohm that goes onto the kathode

idle current at 17ma and with my current cheapo toroidal trafo of rectified voltage 220v+ which suggests a plate load resistor of 13k (i'm using something lesser than that now cuz i've yet to hit koba/slt to pick up more components)..

and triode strapping.. just a grid stopper of 500ohms or 1k on the grid to reduce oscillations, and a anode load of 10k between anode and ground, capacitatively coupled to output with cheap 10uf 400v caps

i'll draw it out soon.. its a lot simpler than it sounds....

design a pcb and make a kit! p2p is too chim for the bulk of us!

actually dont need PCB bah..its quite simple a design plus normal PCB copper is not quite "audio grade"

i'm planning to rebuild it soon, and might adopt the typical "vintage amp" layout which is much easier

something like this of the mullard 20 watts will look neater

thanks.. prototyping right now..

intending to vary the anode load and the bias, if it goes well, it could very well be a aural master piece, with the cheapest of parts the whole amp only costs a hundred over dollars, but some people say its 心里障碍for something that cheap to sound ok/good, so i might build a 1k+ part cost version of this.

built a c3g amp in triode mode based on the datasheet specs

the sound? superb! no wonder pre-amps of reference standard uses these tubes, i.e. ypsilon, ayon etc, yamamoto uses c3m to drive their 300b in their A11 amplifier.

whole amp was rigged out of spare parts here and there, including an el'cheapo power supply and simlim tower parts.. nothing audiophillic as it was just a prototype to see if tube sounds good before using good parts etc. the only expensive thing was the blackgate cap on the cathode because i couldnt rummage out anything of the value required out of my stash except the gates

coupling cap to output is cheap german mkp capacitors etc, total wiring with up-occ copper (leftover from old project), original NOS siemens socket as i couldnt find other cheap loctal sockets in singapore thus had to sacrifice my NOS stock.

any non-headphone tube amps to share?

SRPP is "old school" but still sounds good as ever

but my main preference now is still SESS (single end single stage)

is that a sprague orange drop cap i see there?

i use a pair too

how you like the grado with this amp? i once had an sr80 with it but it wasnt quite my cup of tea so i went beyers

Wow really detailed

Will it help with the heat if I use 2 LM317s in parallel for each side?

 

Anyway any suggestions on maxing out the caps c1 and c2?

i still dont feel a need to max out the caps unless you know the sound of what you're going to make.

start with a cheap cap, and if the setup sounds good, put in better caps.

the prices of a pair of good capacitors can buy you a commercial amplifier already..

I used 24k for R7. As for hum wise, I dont think there is any but I believe better headphones may tell a better story.

 

Used 6N1P throughout and the current draw too high on the heaters that it pull the voltage below 6 volts. Swopped to 6922 and its much better. Trying out 6DJ8 or 6N23 once I lay my hands on them. Current config is 6n1P on Pre and 6922s on the push pull stage. DC Heaters stablise at 6 volts which is ideal.

 

Almost 30 hours of burning in now, dodgy parts should have been burnt by now. This one looks good.

 

About the BeyerDynamics, what model/price and where to get it?

you're using DC heaters?

i've had good aural results with a 6dj8 on pre and a pair of cheap 6n11

you can consider beyer dt880 etc. sounds pretty sweet on the mj amp

i've one too except i've dismantled the power supply for use in another project

its a good sounding amp if you've weeded out all traces of hum (hey even commercial tube headphone amps hum.. )

i used to use mine with beyerdynamics they go pretty well.

whats your value of R7?

Nice work

thanks

having gotten rid of most of my headphones now i'm using this amp as a pre-amp which works pretty well

sharing a couple more pictures

Ermm... Actually what I don't know is what is what on the schematic

 

Quite new to this so I don't really know much about tubes and I'm not the sort of electronics student either...

 

I'll be using a DC voltage for the heater. Already got the LM317 =)

the dotted line in your schematic in the middle of the circle is the grid, so for left channel you can connect it to G on the 9 pin tube, and for right channel you can connect to G1.

for the resistor 47k & the input to opamp, you connect the tube's plate, which is the anode, denoted by A in the 9 pin diagram.

for your cathode, you actually connect it to ground, the input to ground is paralleled to the tube via a 1M resistor. so you connect K and K1 of the tube directly to the ground.

pins 4 and 5 will be your heater pins.

the LM317 will run hot in this case, you can bend it and screw it to the chassis to use that as a heatsink or buy a chip heatsink

Thanks to neutralzz for the detailed PM he sent me about building this amplifier

 

More details on this amp can be found here

 

The original reason for starting the project was for me to build myself something that can last me till 2011 when I finally go for NS. I'm doing this with the mentality of maxing out every possible component in the amplifier except those that are able to be swapped out easily well hoping that I am able to get the best possible sound out of it!

 

I have already bought the resistors, voltage regulator, op-amp and tubes

 

All I am left with are the capacitors and I am still considering what brand and size I should buy(I'm only a student so I'm only limited to the goodies in Singapore). Size is not an issue here. Price wise... Perhaps $200 for C2 and about 50 for C1?

 

The power supply is still a huge question mark in my head now. Should I get a entry level PSU or just use those AC/DC converters that can be found in hardware stores. I will be trying to power it with a lithium polymer 11.1V nominal 2200mAh battery too.

 

So I hope you guys could help me with the capacitors, PSU and the pinouts of the 6922 tube

 

Cheers! *we need a beer mug emoticon*

well too bad i dont have an account on the other forum so i cant post there

but typically i'm more of a tube purist than a hybrid amp lover, although there are decent sounding hybrids out there

the YAHA is a funny amp, i dont know but due to the extremely low plate voltage, you are far from linearity.. but anyway........the pin outs of an ecc88 is similar to that of 6dj8,e88cc, 6922 etc.

you can find loads of datasheets here : http://tdsl.duncanamps.com/

this is the base of the tube with the pins pointing at you, as a twin triode, you have 2 grids, 2 plates (anodes), 2 cathodes (always close to ground, biased with a resistor), 2 pins for filament heating, and 1 pin for shield grounding, i.e. pin 9

input signal, will always go to the grid, with each cathode as K in the picture, and each anode as A.

the cathode determines the bias of the tube, in this case you are probably not using an automatic bias with a resistor. the anode, must always be connected to a positive charge to draw electrons across. and as for the filament.. just heat it with 6.3v ac or dc will do, with DC being quieter than AC, but AC sounds a little more "lively" at the expense of slight hum.

Another amp completed over the weekend

single end single stage design

its actually quite hard to get 50 constructive posts, the only way is to use the forum to "chit chat" with one liners and all that. i think it will take me 1 year to hit 50 posts.

oh well.

the buy/sell section's slow moving with the same items going on and on though.

 

darker background, better separation, more details came out of nowhere too

does it improve cd ripping? i'm backing up a ton of good cds using EAC so if it improves the data readout that would be useful.

It not about it's ability to drive speakers, it about how well it sound. Unless you're a master of DIY. Eg Sun Audio SV-2A3, those built by Frankie from Well Audio sound so much better those DIYers.

 

I've seen many DIY solid state amps that come and go. Some of them are much bigger and much more power than B24. But only few that made it to sound good.

 

Designing and making an amp is an art which performance is affected by too many factors like soldering, wiring and matching of components. From what I learn from those into DIY, getting the best parts doesn't ensure the best sound. So to build an DIY product, you'll need to have vast experience. Any mistake is very costly. So most prefer to make tube amp as it's circuit is simpler and chance of sounding good is high, how well it sound depend more on the characteristic of the tube use.

 

http://images.google.com/images?client=saf...=N&hl=en&tab=wi

 

http://www2.big.or.jp/~sunaudio/index_e.html

the sun audio only sounds good because of the tamura OPT, for OPT there is no doubt on performance of expensive permalloy trans. i had a pair of hammond transformers which i threw out after going permalloy.

tamura prices have gone up significantly over the years driving sun-audio prices up. back when i was still fiddling around, a sun-audio SV2A3 was 2k flat. now current shipment from japan's btwn 3.3k to 3.8k sgd. some of the tamura main trans are at 1.3k each.. lundahl prices went up 50%.. eventually most turn to hammond cuz its still cheap and in good supply.

Aiyah, whatever your dream is, just get it and be happy. That's the thing about consumer choice, you can buy anything you like.... and then aim for the next thing in the near future!

it was a regret that i couldnt moonlight and run a small headfi/hifi business. its good money due to human subjectivity in audio preferences and experiences, different combinations will sound different, but good or not its relative to a variable yardstick.

whichever the case, its always win win situation for manufacturers and retailers

looks like they pulled the DAC from xiangsheng's english site, on the chinese site there's an update in red that says

"翔声DAC-01同轴光纤USB胆输出解码器兼耳放新品上市网站直销价598元。运费根据地区不同实际收取。（淘宝客户请参照淘宝店价格）

本公司保留对本机器因为改进性能需要而进行的修改参数、修改线路、改变布局等的权利，并不再另行通知。但保证高于原设计指标和性能。" which i didnt notice when i inquired about the DAC01 from them last month, looks like they are updating the circuit etc.

the old OEM XS DAC is still available from XS direct as of two weeks ago, to save on shipping you can choose to mass order a few pieces if you like the sound. straight from factory, price quoted to me is 82 USD each.

the missing link

 

mundorf wires

mundorf solder

furutech plug

***** ****

 

nice my favourite wires. almost everything i have is running on mundorf 1% gold silver now.. including using them as speaker jumpers.

which mundorf solder is that? the 3.8% silver or the 9.5% silver one? i have one reel of the 9.5% silver one which can be quite a pain to work with cuz of the melting temp at 300deg odd, you will need abt 40-50 watt soldering iron for a good joint. 20 watt irons can do the job, but not as optimum.

take care of your hearing, use less supraaural cans when listening to highly dynamic music

its one of the primary reasons why i quitted headfi, i cannot cope with listening for too long to any cans without having a mild ear ache

Don't be surprise that they might have it. Just email them to check. Fyi, the best 6SJ7GT is still Sylvania.

will email them.

its all subjective though, i prefer phillips 6sj7gt over the sylvania, and none of the metal shelled versions. this is despite the jan phillips having a below par construction which results in slight microphony.

however this is only spoken in the context of the synergy/complimentarity between 6sj7 and my preferred 2a3 monoplate/2a3 shuguang in application.

Hope this help. US$9 each.

 

http://www.dbtubes.com/en/home.html

tungsol mesh? if its 9 euro each i'll buy 50 in to keep

neutralzz: Are you using any equipment that uses that ultra rare tubes? Or keeping it to see the price rise in the future?

just adding to my collection, as i'm doing quite a bit of DIY, so good tubes come in handy when i build pre-amps. i collect resistors too, i.e. shinkoh, holco, allen bradley.

as for keeping them as an investment.. i dont know that never came to mind.. hmm..

anymore lobang for this?

its quite uncommon and its the only pair i managed to get. i saw a quad before but that was last year in china, which i didnt take cuz i didnt agree on the price.

maybe ical can help you

i've not run in the tubes yet to test their sonics.. and may be putting them into my collection instead..