All gain depends on the tube preamplifier increase signal to 17.5dB. J-Fet voltage and power stage of this amp make 4dB more. Whole gain is 21.5dB
Attachments
MJ802 BJTs.
Hi Gaborbela,
The first MJ802s (30 off) I bought 7 yrs ago from Mouser USA are ST Micro devices. 4 years ago I bought some more (30) from RS Components (ON Semi) and these are stamped with the "MEX" mark. This is probably due to the fact that ON Semi took over quiet a few of the Motorola plants and one of them was in Mexico - others are all over the world now but the other large and oft found marked BJTs were from Malaysia. Also, remember that the original RCA 2N3055 was an 800kHz device, but the newer ones are all 2.5MHz. The MJ802 is specified ta 2MHz, but is a 30A device compared to the 15A of the 2N3055.
There is a good chance that some of the stuff out there is NOS and should be quite safe especially if its from Mouser, RS or Digikey. They all have good reputations.
All the best with your build, Kevin
Are those a good quality MJ802 for the high power (2005) version JLH
I have some 20 pairs of Onsemi MJ15003 together with the complementary MJ15004 (I can separate them) but also I can use them for a P-P amp in the future.
My question does those trannies wort to invest or I should go with the existing ONsemi?
6PCS Transistor MOTOROLA/ON/ST TO-3 MJ802 MJ802G | eBay
I do not recognize these brand.
I can buy the cheaper ONsemi MJ802 but I am not sure if they are the real things. Made of Mexico some has the Motorola logo.
At these moment I do not want to place an order at a reputeble store.
Greetings
Hi Gaborbela,
The first MJ802s (30 off) I bought 7 yrs ago from Mouser USA are ST Micro devices. 4 years ago I bought some more (30) from RS Components (ON Semi) and these are stamped with the "MEX" mark. This is probably due to the fact that ON Semi took over quiet a few of the Motorola plants and one of them was in Mexico - others are all over the world now but the other large and oft found marked BJTs were from Malaysia. Also, remember that the original RCA 2N3055 was an 800kHz device, but the newer ones are all 2.5MHz. The MJ802 is specified ta 2MHz, but is a 30A device compared to the 15A of the 2N3055.
There is a good chance that some of the stuff out there is NOS and should be quite safe especially if its from Mouser, RS or Digikey. They all have good reputations.
All the best with your build, Kevin
Does someone recognize these transistors?
6PCS Transistor MOTOROLA/ON/ST TO-3 MJ802 MJ802G | eBay
The reason I ask!
If someone fakes transistors very likely will mark those ON semi, ST etc well-known manufacturer.
6PCS Transistor MOTOROLA/ON/ST TO-3 MJ802 MJ802G | eBay
The reason I ask!
If someone fakes transistors very likely will mark those ON semi, ST etc well-known manufacturer.
Hello to everybody!
I apologize for the intervention different from the technical character.
I do not know if others feel this need or if it is simply my limitation, but I would like to pay attention to the intelligibility or understanding of certain topics, particularly when someone changes, experiments with new ideas, refines details or substitutes some components and get better or more regressive results compared to the previous situation or better to a typical situation, I think it would be more useful for everyone, to describe the results obtained with greater precision and accuracy. Specifically, speaking of the amplifier JLH and placing that the ultimate interest are the sound characteristics, identifying a series of parameters (which are always the usual> bass, mid, treble, spatiality height, depth, width, general color brightness, transparency , dynamics, contrast, etc.) to be able to express more precise and detailed observations in order to offer a reason for greater clarity in the results achieved and then direct any other actions towards more targeted choices to individual needs, expectations, ideas. I think it could be a more profitable way for the community to be able to enjoy your hobby!
I hope however that this is not only my limit, in this case as not said indeed I apologize, but when you realize situations that could be really interesting for everyone and you comment on everything with an imoticon or some sign of punctuation is to wonder why the tread is published ... by not offering any objective result. Maybe it will be my old age and pity me for this, but it's a question I often ask myself.
Thank you so much for the attention I hope you have given me, I extend my best regards to everyone.
I apologize for the intervention different from the technical character.
I do not know if others feel this need or if it is simply my limitation, but I would like to pay attention to the intelligibility or understanding of certain topics, particularly when someone changes, experiments with new ideas, refines details or substitutes some components and get better or more regressive results compared to the previous situation or better to a typical situation, I think it would be more useful for everyone, to describe the results obtained with greater precision and accuracy. Specifically, speaking of the amplifier JLH and placing that the ultimate interest are the sound characteristics, identifying a series of parameters (which are always the usual> bass, mid, treble, spatiality height, depth, width, general color brightness, transparency , dynamics, contrast, etc.) to be able to express more precise and detailed observations in order to offer a reason for greater clarity in the results achieved and then direct any other actions towards more targeted choices to individual needs, expectations, ideas. I think it could be a more profitable way for the community to be able to enjoy your hobby!
I hope however that this is not only my limit, in this case as not said indeed I apologize, but when you realize situations that could be really interesting for everyone and you comment on everything with an imoticon or some sign of punctuation is to wonder why the tread is published ... by not offering any objective result. Maybe it will be my old age and pity me for this, but it's a question I often ask myself.
Thank you so much for the attention I hope you have given me, I extend my best regards to everyone.
Gaborgela - I don't recognise the logo, these are not ON semi, Motorola nor ST AFAIK, so I would give those a miss.
You should be able to buy genuine ST (with ST logo) or ON semi (was Motorola) and old stock MJ802 would have the Moto batwing logo. ON Semi devices are now generally "G" suffix.
You should be able to buy genuine ST (with ST logo) or ON semi (was Motorola) and old stock MJ802 would have the Moto batwing logo. ON Semi devices are now generally "G" suffix.
That's a spectacular price, I think it would cost me more than that to buy the 2 x 10,000uF caps on that board..
6PCS Transistor MOTOROLA/ON/ST TO-3 MJ802 MJ802G | eBay
The logo is that of Diotec Semiconductor (Germany). Whether the parts were manufactured in Germany or China is always uncertain with NOS components because all major brands, including On-Semi, now use sub-contractors who do the actual manufacturing, usually somewhere in Asia. Otherwise, you'd be paying an awful lot more for those respected brand parts.
The logo is that of Diotec Semiconductor (Germany). Whether the parts were manufactured in Germany or China is always uncertain with NOS components because all major brands, including On-Semi, now use sub-contractors who do the actual manufacturing, usually somewhere in Asia. Otherwise, you'd be paying an awful lot more for those respected brand parts.
Have tested on saturday with a friend: "JLH-3-transes-version", "JLH-follower", JLH-single gain" (# 4522, # 4525):
Starting with the follower: extreme clean and smooth, quiet (naturally;-), wide and open. No deaf-aid! (Noise and distortions do help listening: detection, location)
"Single-gain": More deaf-aid;-) Very fine blanket of distortions. Super sound too. Louder (naturally;-), seems minimal harder, more contoured - but the result of "deaf-aid"-)
All 3 transes: like disco, or party;-) Compared with the mentioned minimal-"amps"-) Less of details, less of FINE contours, less of solution, of FINE colouring, but a dream!!!
The balanced follower: balanced-characteristically: much more quiet, much more contour, much more deep and depth, much more...-)))
I am bound to say, never I have built a original JLH;-! Have seen this circuit and had to alter. And there is no doubt that a 3-transes-version sounds better: finer, more solution, cleaner.
@ Mleod: Do you want "more bass", still;-? Remove the bootstrap;-) More body, more deep and depth, less noise, more fluid, better "dynamic", more "ON POINT"-) And remove your 3-way-speakers?-)
Hello to everybody !
Mr. Cumbb
Well, in the end I managed to find the bass doubling the input capacity and increasing the feedback elcap. Frankly the bootstrap that continues to show me I can not identify it, I would need more precise information based on the scheme I entered some time ago. However, the speakers I use are 2 way home bilt not 3 way although in perspective I think for further refinement I would not exclude trying this solution, but for now I feel satisfied with what I have assembled. I've been following this tread for about a year because I'm interested in the implementations that this amplifying circuit will produce> even I was fascinated by the unexpected results despite the simplicity.
However, I remain thrilled by his statement
I am bound to say, never I have built a original JLH;-! Have seen this circuit and had to alter. And there is no doubt that a 3-transes-version sounds better: finer, more solution, cleaner.
I wonder how it is possible not having built any JLH affirm that an arbitrary solution produces a better result than the original ..... sorry but I just can not understand, maybe my English is not so rooted or I do not know .. perhaps his experience in matter and so great that he can mentally simulate the outcome of a circuit rather than another, in which case I really compliment you with the qualities that you excel ... good, bravo!
Thank you for the attention you wanted to give me and suggestions kindly bestowed, I take this opportunity to offer you my best regards.
CIAO
Mr. Cumbb
Well, in the end I managed to find the bass doubling the input capacity and increasing the feedback elcap. Frankly the bootstrap that continues to show me I can not identify it, I would need more precise information based on the scheme I entered some time ago. However, the speakers I use are 2 way home bilt not 3 way although in perspective I think for further refinement I would not exclude trying this solution, but for now I feel satisfied with what I have assembled. I've been following this tread for about a year because I'm interested in the implementations that this amplifying circuit will produce> even I was fascinated by the unexpected results despite the simplicity.
However, I remain thrilled by his statement
I am bound to say, never I have built a original JLH;-! Have seen this circuit and had to alter. And there is no doubt that a 3-transes-version sounds better: finer, more solution, cleaner.
I wonder how it is possible not having built any JLH affirm that an arbitrary solution produces a better result than the original ..... sorry but I just can not understand, maybe my English is not so rooted or I do not know .. perhaps his experience in matter and so great that he can mentally simulate the outcome of a circuit rather than another, in which case I really compliment you with the qualities that you excel ... good, bravo!
Thank you for the attention you wanted to give me and suggestions kindly bestowed, I take this opportunity to offer you my best regards.
CIAO
