Techno
Is there any replacement of 2N5551 and 2N5401 in techno amplifier? I got them though but when I test the 2N5401 the pins are different than its data sheet may be they are fakes.
Regards
Hi sir,
Is there any replacement of 2N5551 and 2N5401 in techno amplifier? I got them though but when I test the 2N5401 the pins are different than its data sheet may be they are fakes.
Regards
Some of your decisions are strange! First you want to use SSM2220 instead of 2xBC556 - and you don't consider that as costly? - but later you are thinking that two-three small caps are costly? Some of your criteria are not consistent.
Maximum operating voltages of SSM2220 are talking against it’s use in Techno. Better order 30-50 BC-s and find two matched pairs. You can also use 2SA970 there but take care about different pinout. 5401 should have same pinout as 5551, otherwise they are probably fakes. You can replace them with 2SC2240 again observing different pinout!
Small caps should be MICA or Polystyren (aka Styroflex) if you can supply those. Building high quality audio amplifier IS A COSTLY BUSINES! You can’t run away from that. One can try to cut corners with cheep components but at a cost paid in quality! Techno, as well as most other properly designed amps, will work with wide variety of components but final results will reflect whether you’ve made right decisions.
Please have someone from the legend master plan and design the PCB? Sincerely email retro.house @ yahoo.com
I am not sure that I understand properly, but it seems you are asking for PCB and Layout files of Legend Stage Master? If that is the case, write to me on my direct mail:
kia-ora(at)blueisp(dot)co(dot)rs
kia-ora(at)blueisp(dot)co(dot)rs
Of course you can, they are even better... at least I like them more than MPSA. Just make sure that you match them the best you can!
Image - TinyPic - Servizio di hosting d'immagini, condivisione immagini & hosting di video gratuito This scheme works and the 4 ohm? with thanks
Techno Amp bias
Hi Sir,
What's about the bias of the Techno amp. 65mA per pair ? please correct me
Regards
Hi Sir,
What's about the bias of the Techno amp. 65mA per pair ? please correct me
Regards
No Wasim, that's too low. For best results don't go under 100mA per pair and provide good heatsink!
Techno
Thank you Sir, My Techno is almost complete I will post pictures soon
Regards
Thank you Sir, My Techno is almost complete I will post pictures soon
Regards
Techno
Hi dear Sir,
I got some problem while biasing the Techno. when I turn it on through 20w16 ohm resistors my multimeter reading goes up to 1.4A. The Pot is not working at all. After some time the resistors are very hot. The LED turn on but very dim I checked everything and it seems to be fine. The same problem is coming with both of the channels any advice?
Regards
I'll be waiting for you Obi-Van🙂
Hi dear Sir,
I got some problem while biasing the Techno. when I turn it on through 20w16 ohm resistors my multimeter reading goes up to 1.4A. The Pot is not working at all. After some time the resistors are very hot. The LED turn on but very dim I checked everything and it seems to be fine. The same problem is coming with both of the channels any advice?
Regards
Either one or more components are faulty or you make mistake somewhere – soldering or wrong oriented part. You need two instruments (multimeters) to connect at the same time to adjust properly. One as a DC voltmeter on a range 10-20V for start, should be connected between speaker output and ground and another as a DC ampermeter in positive (or negative) rail to measure current. You also have to install protective resistors (those 16 ohms/20W) in both supply rails. That way you will protect components during the first turn on procedure. I am very suspicious about your statement that BOTH channels have identical problem???
For start, make input short circuit and do not connect anything on the output (except voltmeter of course). Short C and E of Q14 (BC556 “Vbe” transistor) and there should be just a very small current flowing if drivers and finals are OK. If current is substantial one or some of them are blown or you have some short circuit somewhere – check for short between collectors of transistors and metal of the heatsink or solder bridges between PCB tracks!
Try this and tell me what is going on! Never keep unit on for more than few seconds if you see that something is obviously wrong!
For start, make input short circuit and do not connect anything on the output (except voltmeter of course). Short C and E of Q14 (BC556 “Vbe” transistor) and there should be just a very small current flowing if drivers and finals are OK. If current is substantial one or some of them are blown or you have some short circuit somewhere – check for short between collectors of transistors and metal of the heatsink or solder bridges between PCB tracks!
Try this and tell me what is going on! Never keep unit on for more than few seconds if you see that something is obviously wrong!
More Info and a larger clearer image wanted....
Sorry for "resurecting" this thread, but this amp caught my eye...
Anyone want to share a lil bit more about it ??? 😀
Sorry for "resurecting" this thread, but this amp caught my eye...
Anyone want to share a lil bit more about it ??? 😀
Techno
Hi dear Sir,
Finally I got the problem and resolved the Bc556 on heatsink was not working. I replaced it after that the bias was set very smoothly 200mA total and now Techno is on and producing sound. Sir only problem I have is that I have little hum in my one channel. I am using zubal network as explained in techno diagram. Sir what should I do now? thanks for the help
Regards
Hi dear Sir,
Finally I got the problem and resolved the Bc556 on heatsink was not working. I replaced it after that the bias was set very smoothly 200mA total and now Techno is on and producing sound. Sir only problem I have is that I have little hum in my one channel. I am using zubal network as explained in techno diagram. Sir what should I do now? thanks for the help
Regards
I believe it’s a great amp Adrculda, but I seldom want to talk and promote my designs. Self-promotion is a type of attitude I deeply disrespect in spite of the fact that it is so “in fashion” this days. I follow my "moto" about modesty under my posts...
Here is what other people that built TAG have to say:
(Those are posts from some Serbian forums)
""" PILE :
When I saw that the Bora is in the functional prototype stage, and what Bob Cordell thoughts about ThermalTrak transistor I got no doubt any longer. Such a challenge I need.
Amplifier that still nobody has managed to make (factory application does not count), huge potential, and names like Mr.. Cordell et al. and Dr Jagodic...
On this occasion once more I want to thanks Bora which uploaded a prototype and helped to push the project to the end.
TAG was born... TAG stands for = Talisman Audiophile Grade
Dual mono block. 2 transformer 500VA, 4 x 25,000uF Sprague "blue jars".
For the input level 2 transformer 50VA and stabilized power supply.
Technical details, I won't explain. It has been already done by the above mentioned gents.
The amplifier is very demanding to create. Requires a great adjustment precision and matching of important components (input section). Several times I even changed the whole group of transistors and some more components until I achieve results I wanted. Amplifier, although of a fantastic speed, is very stable. DC Offset doesn't exist, noise-hum on speakers too.
Powering up is quite quiet and "cultural" so that I have neither delay nor protection of the DC output.
ThermalTrak transistors definitely turning a new page and give the possibility
constructors throughout the world to push the boundaries a little further and offer us amplifiers that are a little closer to the truth.
Now how it plays. Tremendously.
I will use the phrase audiophile, but I will try to describe in my own words.
Reproduction fidelity is typical of a well designed bipolar amp.
What distinguishes it from other amplifiers... the speed, power, control.
Speed (slew rate 200V/μs simulated) enables much greater flow of information, and this you can hear.
The music is richer, with more details. The complex that is more pronounced.
Symphony with a full orchestra, and my favorite Elgar sound completely different. Removed the curtain in front of the orchestra. Each artist is where it should be, it is possible to follow certain instruments which wasn't possible earlier because of the "blur".
Because of oversized power supply, current is tremendously capable.
Now I sound like a commercial for car tires. What is a meaning of power without control. Tag controls amperes perfectly and that can be heard as a very deep, firm, well defined bass. If it were not so on Friday, membranes of my small woofers would ended on the opposite side of the room.
Now we have a new problem. 6.5-inch mid bass is not able to demonstrate the full potential of TAG. It is asking for a three way box with serious bass.
This is the pre-final version that was supposed to demonstrate the potential of the new transistors.
*********************
MLAVA:
I'm still under the impression of the pre-final version. Knowing PILE (PILE is a forum NICK of Mr. Bane Tasic) this pre-final always make me panic slightly, because I know what it means... days and days of fine trimming, adjusting and tests. That man rarely says "that's it". Chicken (word PILE in Serbian language means small Chicken!) otherwise have a gift to bring every detail to perfection. His devices combine careful planning and more carefully making. Is it bad or not I don't know, but its devices look like they came from factory top devices.
I just have to mention that the front panel made by Leonardo put a dot to the "i". Frankly I have no idea what else could be done to an amp to sound better. Great unit - great sound. All instruments are on the number and accurately positioned whatever music it plays. I think that here fall into the water a myth that one amp is excellent for one type of music
and another amp for other kind. Whatever was submitted to the TAG it delivered correctly. And how much should be. You want to destroy the walls? OK... looks possible with TAG. You want it quiet? Easily... without any loss of quality, detail, no distortion ... I never heard an amp with greater power reserve! We arrive at the aforementioned three-way speaker box. TAG killed our last hope that two-way box (no matter how perfect component it contains) can play all properly. It can, but ... It is next "mental worm" that slowly begins to work. Plans are already here.
What about constructor? He is to blame that he spoiled us, so that we can only expect such designs from him. And what's more, every next we expect to be better. Therefore, what's the point of any comments. What kind of comment one can give about the man known throughout the
planet. His works speak for itself.
TAG of course has a big disadvantage.
TAG is not mine.
"""
Wasim, disconnect preamp or any source of signal, short your PA inputs, adjust BIAS and DC in the output, connect speaker and listen. If there is hum from the speaker it is probably related to your wiring and grounding of amps PCB-s and PSU. Some really minor noise-hiss from tweeters with your ear very close to that driver is possible and acceptable.
Attachments
Techno
Hi Dear Sir,
I would do that but the sound quality is extremely good. Very clean sound, the mid and the high is also very good. It's a very good amp. Thanks for the design.
Now I need to make a enclosure for Techno.
Regards
Hi Dear Sir,
I would do that but the sound quality is extremely good. Very clean sound, the mid and the high is also very good. It's a very good amp. Thanks for the design.
Now I need to make a enclosure for Techno.
Regards