Greetings,
I have a question for the master again.
Can I replace 2sc5200 with 2n6259
I have whole lot of 2n6259 and I Wonder is it
Interchangable with 2sc 5200 for LF amps.
I have a question for the master again.
Can I replace 2sc5200 with 2n6259
I have whole lot of 2n6259 and I Wonder is it
Interchangable with 2sc 5200 for LF amps.
2SC5200 Datasheet(PDF) - Fairchild Semiconductor
2N6259 datasheet(3/3 Pages) ETC | HIGH VOLTAGE, HIGH CURRENT POWER TRANSISTORS
What is an LF amplifier? An amplifier that reproduces only low frequencies ?
2N6259 datasheet(3/3 Pages) ETC | HIGH VOLTAGE, HIGH CURRENT POWER TRANSISTORS
What is an LF amplifier? An amplifier that reproduces only low frequencies ?
They are suitable for power, voltage and current. Lower current gain (15/60). Very low frequency (200 kHz).
Replacement options depend on the specific circuit.
Replacement options depend on the specific circuit.
200 khz Ft output transistors are not suitable for reproducing sounds like top octave piano & tinkly bells. See the 1966 reviews of the dynaco ST120 versus the vacuum tube amps available at the time. The RCA TO3 transistors available in 1966 had 400 khz or 200 khz Ft.
However if you are building a sub amp for frequencies under 400 hz, no problem with 200 khz transistors.
However if you are building a sub amp for frequencies under 400 hz, no problem with 200 khz transistors.
Real, honest, non-fake 2N6259’s are actually a good choice for a subwoofer amplifier. Far more rugged than 2SC5200’s. If your circuit can be made to work with them without oscillating and has the drive capability to use low gain outputs. Those are big ifs. Don’t just stick them in some board off E-bay. It’s not just a 1 for 1 swap without some analysis. You can certainly design around them, should you choose to.
Of course working with TO3’s is a royal pain in the *** compared to flatpacks.
Of course working with TO3’s is a royal pain in the *** compared to flatpacks.
Thanks for the response. Sound reproduction is not so problematic, since the amp would be used for a quiet band practice. But i deubt these outputs will sacrifice the sound since i have a TIP41 for VAS duty,having built in Miller cap... I know you re gonna kill me 🙂 but im not going for the fidelity i just wanna use up parts in my workshop.
If a post the circuit later when i get home, could you tell me if they can be interchanged? I sure will and thanks for response really i appreciate you guys are experts.
If a post the circuit later when i get home, could you tell me if they can be interchanged? I sure will and thanks for response really i appreciate you guys are experts.
Can be used instead of 2N3055 with minimal alterations. For example, in the amplifier Quad 405. But you need TIP42. 🙂
Yeah, any place you *can* use a 3055 you can stick a 6259. But maybe not in a circuit designed to take advantage of output transistors that have a 30 MHz fT and a gain stays up at 100 out to 8 amps. Put a 6259 in something like that and the results will be disappointing at best. Quite possibly break into oscillations due to the non-dominant poles expected to be up at several MHz dropping into the hundreds of KHz eating into the phase margin. Blow out the driver transistors due to just drawing too much off of them, at worst.
Put them in a design that can handle the base current they will draw, and conservatively enough designed for stability and they’”ll be more than fine.
Put them in a design that can handle the base current they will draw, and conservatively enough designed for stability and they’”ll be more than fine.
Ok, yes TIP42 im sorry im kinda new to audio field. The schematic in question is used in my homemade guitar amp and it works really well. I have evem made amps for monitors for my band with it because we are on a tight budget and i work with parts i have. The schematic is a preety sh***y amp i know and was modified by a kind member od diy audio on my request. So, can i stick in the 2n6259? I dont care if i loose fidelity i care for
stability in this case.
Yeah, that circuit will work with 2N6259’s or any of the old 100+ volt TO-3’s. Using TIP41/42 drivers makes using fast outputs a waste - and might even be more unstable than OAS ones (old and slow).
But using a TIP42 VAS is a bad plan. Yeah, I understand about the “built-in” Miller capacitor, but Miller capacitors work better when they are linear, not a highly nonlinear function of voltage. It will work better with a BD140 and separate capacitor from collector to base. Even with slow outputs you would notice an improvement.
But using a TIP42 VAS is a bad plan. Yeah, I understand about the “built-in” Miller capacitor, but Miller capacitors work better when they are linear, not a highly nonlinear function of voltage. It will work better with a BD140 and separate capacitor from collector to base. Even with slow outputs you would notice an improvement.
Thanks for your help.
Should you know what value of miller capacitance should i use if i use bd140?
Just to be in the baulpark. About 100 pF - ish??
Should you know what value of miller capacitance should i use if i use bd140?
Just to be in the baulpark. About 100 pF - ish??
What about stability if the TRs of the input differential pair are not matched correctly?
What would be the minimum HFE difference between them ?
2N3905 datasheet(1/1 Pages) SAMSUNG | PNP EPITAXIAL SILICON TRANSISTOR
What would be the minimum HFE difference between them ?
2N3905 datasheet(1/1 Pages) SAMSUNG | PNP EPITAXIAL SILICON TRANSISTOR
Match input transistors for vbe. More important than for beta.
Most important is matching for current in the intended circuit. Many input circuits don’t do a good job of enforcing balance. This one does.
Most important is matching for current in the intended circuit. Many input circuits don’t do a good job of enforcing balance. This one does.
This was designed to be used with 8 ohms. Am i gonna kill it with four? is there anything that could be done to use 4 ohms?
PS: with 2n6259 output trs
PS: with 2n6259 output trs
1. Select the output and pre-output transistors for the maximum current gain (and equality). Use parallel output transistors.
2. Instead of a cascode, use a conventional voltage amplification stage with a resistive load and a bootstrap. Increase current. Add EF before the transistor. You can after.
According to the classic recommendations of the RCA.
3. Use a transformer with a power of at least 200 watts.
#53 https://www.diyaudio.com/forums/att...omplementary-power-output-cm911-schematic-jpg
2. Instead of a cascode, use a conventional voltage amplification stage with a resistive load and a bootstrap. Increase current. Add EF before the transistor. You can after.
According to the classic recommendations of the RCA.
3. Use a transformer with a power of at least 200 watts.
#53 https://www.diyaudio.com/forums/att...omplementary-power-output-cm911-schematic-jpg
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+-47 v rails is too much for 1 pair 2sc5200 output transistors @ 4 ohms. buy another burnt up amp or find a transformer more like +-40. Note transformers are sold by full load voltage, so a two winding 35 v transformer * 1.4 - 1.4 v for two diodes is +- 47 v.
This goofy circuit has no miller capacitor near R7. I suspect the circuit didn't make it to the checkout floor. 10 pf b-c caps, ha!
BTW with TIP41c/42c drivers, this amp is not going to reproduce top octave piano or tinkly bells even if the output transistors are 2 mhz. I had to change those to MJE15028/29 to get those instrument sounds on my AX6. for guitar, slow cheap TIP41c/42c are fine.
This goofy circuit has no miller capacitor near R7. I suspect the circuit didn't make it to the checkout floor. 10 pf b-c caps, ha!
BTW with TIP41c/42c drivers, this amp is not going to reproduce top octave piano or tinkly bells even if the output transistors are 2 mhz. I had to change those to MJE15028/29 to get those instrument sounds on my AX6. for guitar, slow cheap TIP41c/42c are fine.
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+/-47 volts isn’t too much for a single pair of 2N6259, even on 4 ohms. But it is too much for a poor little pair of C5200’s.
iF they are real 6259’s and not fake. China fakes from E-bay will blow up faster than C5200’s. These transistors haven’t been produced since about 1980 so that is a real possibility. If what you have are NTE, Solid State, Central, Multicomp, or Mospec, what you *really* have are MJ15024’s not true 2N6259’s. In most cases (including this one) they would work. Original RCA’s with 1970’s date codes do show up from time to time, but they are few and far between.
iF they are real 6259’s and not fake. China fakes from E-bay will blow up faster than C5200’s. These transistors haven’t been produced since about 1980 so that is a real possibility. If what you have are NTE, Solid State, Central, Multicomp, or Mospec, what you *really* have are MJ15024’s not true 2N6259’s. In most cases (including this one) they would work. Original RCA’s with 1970’s date codes do show up from time to time, but they are few and far between.
Thanks everybody, especially wg_ski!
I will post a picture of trs and beleive me they re pretty old.🙂 oldest in my shop except for 2n3055 and 2n3773s
I will post a picture of trs and beleive me they re pretty old.🙂 oldest in my shop except for 2n3055 and 2n3773s