Hi everyone,
I have finished the design process up to my knowlege with the help of
Ed Brown, who has given his great advice freely, But I want some others here to comment on this amplifier design since this will be used for 2k and up for a pair of compression drivers. Any advice will be appreciated since I have a friend that is going to wire this up for me, and WE WANT TO KNOW if THIS WILL WORK OR NOT! Need a little insurance here folks! I appreciate any constructive advice not criticize please. Pianolydia
I have finished the design process up to my knowlege with the help of
Ed Brown, who has given his great advice freely, But I want some others here to comment on this amplifier design since this will be used for 2k and up for a pair of compression drivers. Any advice will be appreciated since I have a friend that is going to wire this up for me, and WE WANT TO KNOW if THIS WILL WORK OR NOT! Need a little insurance here folks! I appreciate any constructive advice not criticize please. Pianolydia
No, it won't. First of all, the schematic is a bit hard to read with the active elements drawn as their base pinouts. Then, you use two RC sections of 560pF*0.12M=67us. This is a highpass cutoff frequency of 15kHz. This means you won't hear anything. Lose C1 and R5 and change C2 to 0.1uF. Paralleling two triodes in an SE configuration isn't something I would do but that's a matter of taste.
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I don't like the value of C1/C2...560pF together with 120Kohm they rolls of about 2,3 Khz (in the bass)...is that intended?
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Yes, this amplifier will only drive a pair of 4-ohm compression drivers, and I would like to have them roll off about 2k, 2.5k the range I was interested in was from 2k-20k only!
Ok..next step is to built it and take mesurements...oscilloscope and tone-generator least are needed.
Otherwise I agree with Regenpak...
Otherwise I agree with Regenpak...
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Ok, but, Why did Regenpak, mention what he said anyway? This amplifier is going to be used as a standalone HF amplifier for two compression drivers in an bi-amplified situation.
I think he talks about matching the tubes...thats even more importent regarding paralleling...but its not imposibly.
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The 1626's I have are all NOS and Never been used and they are the Military
surplus! Got perfectly preserved New Tubes from 1943!
Out of the 8 tubes I have at least 2-pairs are going to be close, but I agree, none will be exactly the same, no two tubes will ever be the exact same in all catagories of specifications when actually measured, anyone who claims they are, are not being honest, However, that's where cathode bias should adjust for that as well! hopefully....
Ah, I didn't understand the "2k" bit as you meant 2 kHz. Then your highpass makes more sense. And of course it's 15/6.3=2.4 kHz. Still, you may want to match the two triodes in the output but it's not overly critical. And of course the readability of your schematic won't change anything in the actual performance... You even may want to forego the SRPP input stage for a straightforward voltage amplifier with a single 1626 but that'd be a bit overkill. You could use a 6C4 or EC92 or half a double triode.
True, but 5965 is pretty much the same as a 12AV7, the SRPP was an idea that someone told me about as it would give a lower output impedance and resistance so that would be an easier load and less distortion since this is not a negative feedback amplifier. If there is any it is a small amount. I could have gone with a mu Follower instead of SRPP but the advantage of SRPP is as mentioned above seems best of both worlds in those terms.... any comment?
SRPP is only marginally lower impedance than straight voltage amp. And, if you use a 1626 it can be biased so it's much lower than the proposed SRPP circuit. I'd estimate the SRPP to be about 10k. My ECC82 headphone amp was about that. Then you follow it with a two section high pass RC filter which is very high Z from an SE amp perspective. Hence it should be moved to the input stage.
Hi,
If you want drive compression driver a hight ZOUT is better.
Why ?
Because a good compression driver have a acceleration facteur very hight arround 20000.
For a good song, it's better to have a low dumping factor so a higher ZOUT between 4 ohms to 80 ohms.
Another solution is curent amplification and not tension.
Specialy for this job and whith my freind, we have designed and built 2 SPUD amplifier's of 6C45PI or EC8020 / WE437A with special designed opt.
Shortly in new thread, we will describe this new amp option.
If you want drive compression driver a hight ZOUT is better.
Why ?
Because a good compression driver have a acceleration facteur very hight arround 20000.
For a good song, it's better to have a low dumping factor so a higher ZOUT between 4 ohms to 80 ohms.
Another solution is curent amplification and not tension.
Specialy for this job and whith my freind, we have designed and built 2 SPUD amplifier's of 6C45PI or EC8020 / WE437A with special designed opt.
Shortly in new thread, we will describe this new amp option.
Separate cathode resistors (matched 1.5K, each bypassed) can force matched current in output tubes. But I don't think it will be necessary.
I decided on PLLXO Before driver stage!
Hi All, here is the final amplifier design and after consulting with others this is what I am looking for! if anyone sees anything that I need to draw attention to
please let me know....Pianolydia
Hi All, here is the final amplifier design and after consulting with others this is what I am looking for! if anyone sees anything that I need to draw attention to
please let me know....Pianolydia
Need approval on this multi function PLLXO
Hi Everyone, I need some approval on the Band-pass to make sure that this is set up correctly. This is going between the Pre-amp and the Paralleled 1626 output tubes in a SE Darling tube amp. Any thoughts would be appreciated!
Piano-lydia
Hi Everyone, I need some approval on the Band-pass to make sure that this is set up correctly. This is going between the Pre-amp and the Paralleled 1626 output tubes in a SE Darling tube amp. Any thoughts would be appreciated!
Piano-lydia
Attachments
En Vogue Darling Final comments needed!
Good Evening All,
En Vogue is being built as we speak here, I just wanted anyone who is More of a Tube building Veteran, to take a quick glace, as the Amplifier is for Full range but will be running an active crossover thru this Amplifier! SO, Trying to get the Balance of the Best crossover swing I can get, I am having problems picking a Coupling Value Cap, as this is being finalized, If any one out there sees something wrong with this design Please don't hesitate what changes that would need to be made in order to operate to it's potential as this is a low budget amplifier, and I would like to have good sonics, clarity in good inner detail at about 1-watt of power, So this amp is only going to be a 1.5 watt per channel. but I think I have a good design here! I would like to have a front selector switch to switch between the 1626's cathodes just to check the readings from time to time, so that's going to be a challenge to hook up...any thoughts will really be appreciated! Thanks Everyone, Pianolydia
Good Evening All,
En Vogue is being built as we speak here, I just wanted anyone who is More of a Tube building Veteran, to take a quick glace, as the Amplifier is for Full range but will be running an active crossover thru this Amplifier! SO, Trying to get the Balance of the Best crossover swing I can get, I am having problems picking a Coupling Value Cap, as this is being finalized, If any one out there sees something wrong with this design Please don't hesitate what changes that would need to be made in order to operate to it's potential as this is a low budget amplifier, and I would like to have good sonics, clarity in good inner detail at about 1-watt of power, So this amp is only going to be a 1.5 watt per channel. but I think I have a good design here! I would like to have a front selector switch to switch between the 1626's cathodes just to check the readings from time to time, so that's going to be a challenge to hook up...any thoughts will really be appreciated! Thanks Everyone, Pianolydia
Attachments
What size cap? and Where do you mean across it?
Good point!, I am worried about noise, from the bias diodes! Can you descibe a little more how that would be hooked up? Do you mean by-pass a cap around both diodes? what size cap, A film type would be best don't you think? Appreciate you stepping up to the plate here! Pianolydia
Good point!, I am worried about noise, from the bias diodes! Can you descibe a little more how that would be hooked up? Do you mean by-pass a cap around both diodes? what size cap, A film type would be best don't you think? Appreciate you stepping up to the plate here! Pianolydia
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