I know that the word "warmth" has been used a lot about tubes. I don't see it that way. Yes, you'd get a "warm" sound from tubes like 12AX7 and 6SL7 for instance, but that's not what I'm after at all. I use only DHTs including all the small tubes like 26, and if I were looking for a generic word it would be some combination of "vivid, sparkling, detailed, transparent, dynamic, full of life...". Gingertube uses the words "cold, sterile, boring" of SS equipment, and "lively, vivid" is certainly the opposite of that.
I know this discussion is a bit off topic since the OP wants to use his ECC88s, but if he were to "add" something to an F5 I'd suggest that an alternative down the DHT route would be "sparkle and life".
andy
I know this discussion is a bit off topic since the OP wants to use his ECC88s, but if he were to "add" something to an F5 I'd suggest that an alternative down the DHT route would be "sparkle and life".
andy
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Nelson Bass,
Interesting - my power amp (a Baby Huey) output stage is as about as balanced as it is possible to be. The design incorporates a forced symmetry function. I'm about to embark on a new preamp build, I had some conversation with Allen a few months before his untimely end, and he provided me with a "Commercial In Confidence" copy of the SVP2 circuit (the most recent FVP5 variant) and that is what I'm proposing to build. I have considered going something simpler such as SY's offerring. I tend to agree that the "wire with gain" sound is appropriate up to the power amp but have never been happy with power amps with that "philosophy". I have a Hugh Dean SS Power Amp like that and find it needs a tube buffer ahead of it. The power amp I absolutely loathed and could'nt listen to was a top of the line 210W per channel ROTEL (SS) with 0.0001% THD specs ( I sold it within a month of getting it). It went to a guy who bridged the outputs for 400Watts and hooked it up to a Line6 DSP Guitar preamp, that is, it was used for reproducing distortion at ear bleeding levels, I thought that was poetic justice.
This whole thing of-course depends upon where in the spectrum from a "Piece of Wire with gain" through to a "Musical Instrument in its own right" your preferrences lies.
I've has amps at either end of the spectrum (that ROTEL at one end and an rather sickly sweet 845 SET at the other end) and now I'm a firm fence sitter, right in the middle.
Andy,
I have a small stash of mesh plate 26 tubes - perhaps I should look at that.
Formula 22,
Apologies for filling your thread. I guess what we are saying is that if you are happy with that sound then go for it. You may find as many of us do that your tastes change with time and all you can do is build something else and try that too. For the SY offering I referred too above, search "Heretical Preamp" on this forum. It is another ECC88 design.
Cheers,
Ian
Interesting - my power amp (a Baby Huey) output stage is as about as balanced as it is possible to be. The design incorporates a forced symmetry function. I'm about to embark on a new preamp build, I had some conversation with Allen a few months before his untimely end, and he provided me with a "Commercial In Confidence" copy of the SVP2 circuit (the most recent FVP5 variant) and that is what I'm proposing to build. I have considered going something simpler such as SY's offerring. I tend to agree that the "wire with gain" sound is appropriate up to the power amp but have never been happy with power amps with that "philosophy". I have a Hugh Dean SS Power Amp like that and find it needs a tube buffer ahead of it. The power amp I absolutely loathed and could'nt listen to was a top of the line 210W per channel ROTEL (SS) with 0.0001% THD specs ( I sold it within a month of getting it). It went to a guy who bridged the outputs for 400Watts and hooked it up to a Line6 DSP Guitar preamp, that is, it was used for reproducing distortion at ear bleeding levels, I thought that was poetic justice.
This whole thing of-course depends upon where in the spectrum from a "Piece of Wire with gain" through to a "Musical Instrument in its own right" your preferrences lies.
I've has amps at either end of the spectrum (that ROTEL at one end and an rather sickly sweet 845 SET at the other end) and now I'm a firm fence sitter, right in the middle.
Andy,
I have a small stash of mesh plate 26 tubes - perhaps I should look at that.
Formula 22,
Apologies for filling your thread. I guess what we are saying is that if you are happy with that sound then go for it. You may find as many of us do that your tastes change with time and all you can do is build something else and try that too. For the SY offering I referred too above, search "Heretical Preamp" on this forum. It is another ECC88 design.
Cheers,
Ian
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The nice thing about the FVP5 is that you can switch to different input tubes to "tune" thge4 preamp to whatever sound you like. You could even use a DHT as the front end. The output just pushes the signal out in as transparent way as possible. The FVP5 has to much gain with a ECC88 in the front end.
I think the essential difference between the tube sound and the "clinical" SS sound is the effects of large amounts of gNFB which robs the sound of all life. Tubes with no or low feedback preserve the life in the music. My latest preamplifier has 5687's - no feedback and an output transformer which helps reduce gain to usable levels. It is trhe cleanest and most detailed preamplifier I have heard and yet has spade loads of tube induced presence and life.
Shoog
I think the essential difference between the tube sound and the "clinical" SS sound is the effects of large amounts of gNFB which robs the sound of all life. Tubes with no or low feedback preserve the life in the music. My latest preamplifier has 5687's - no feedback and an output transformer which helps reduce gain to usable levels. It is trhe cleanest and most detailed preamplifier I have heard and yet has spade loads of tube induced presence and life.
Shoog
FVP5 pramplifier - schematic?
Or where on the net can be found?
thank you!
P.S.
Otherwise, I tried this a preamplifier with ECC88 Philips Mini Watt and you say sounds good investment!
I agree with you, just insert here the schematic (circuit or project) of the preamplifier.
Or where on the net can be found?
thank you!
P.S.
Otherwise, I tried this a preamplifier with ECC88 Philips Mini Watt and you say sounds good investment!
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The top schematic on this page;
Schematics
Everything to the right is the line stage - everything to the left is the phono preamplifier.
A well filtered linear power supply will substitute for the superreg - shoot for about B+ of 240V DC.
Shoog
Schematics
Everything to the right is the line stage - everything to the left is the phono preamplifier.
A well filtered linear power supply will substitute for the superreg - shoot for about B+ of 240V DC.
Shoog
Total Harmonic Distortion Graph of PP-1C
Hi Shoog!
Such distortion THD I want to get around the preamplifier, but with higher 2H> 0.5%. (as in this amplifier: Total Harmonic Distortion Graph of PP-1C).
And if you can power supply a few words about the preamp with ECC88,...
thank you
Hi Shoog!
Such distortion THD I want to get around the preamplifier, but with higher 2H> 0.5%. (as in this amplifier: Total Harmonic Distortion Graph of PP-1C).
And if you can power supply a few words about the preamp with ECC88,...
thank you
Attachments
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As I suggested before, the preamplifier can be voiced by switching out the front end ECC88 with something else. Think of an old low mu octal valve with a big bloomy sound,which is happy with 100v on its plate.
As for power supply -
6x4
1 to 10uf cap
5 to 10H choke
100 - 300 uf cap
Thats a a good starting point. The circuit has poor power supply noise rejection so you need a very quiet supply - additional stages can be added and final voltage can be tweaked with series resistors. You need to look at the free design software PSU2 to help model a power supply.
Shoog
As for power supply -
6x4
1 to 10uf cap
5 to 10H choke
100 - 300 uf cap
Thats a a good starting point. The circuit has poor power supply noise rejection so you need a very quiet supply - additional stages can be added and final voltage can be tweaked with series resistors. You need to look at the free design software PSU2 to help model a power supply.
Shoog
Guys
If you are unable to propose a schematics (circuit) of good and tested the tube preamplifier with PCC88 or ECC88.
thank you!
If you are unable to propose a schematics (circuit) of good and tested the tube preamplifier with PCC88 or ECC88.
thank you!
You'll have a hard time to find anything better than the RTP3 for E88CC/PCC88: http://www.vacuumstate.com/index.dna?rubrik=8&lang=2
Your asking us to help you design a distortion generator using an inherently low distortion valve - its not an acceptable design philosophy for most of us.
Shoog
How about using a low value anode load resistor i.e. do the opposite of good design practice? That would keep gain down, and reduce the linearising feedback from the anode. Even the ECC88 is non-linear under these conditions. A poor bias point choice would finish the job.
I'm still a "tube nube" anyone know a good book I can download (torrent) on tubes. Anyway I love my tube preamp in my truck and it definitely sounds better with, than without by a huge margin. I use a Nakamichi CD500 cd player for HU and I definitely love tubes, especially since you can easily replace them and change the sound character.
So then what is the difference between tube preamplifier and MOSFET preamplifier?
If distortions are below the THD <0.001.😱😕🙄
thank you
Many MOSFET amplifiers have a very particular mosfet sound despite their low measured distortion. I personally dislike that sound.
Until you go ahead and build your first tube preamp - you will never know. My experience is that there is far more to the sound of a preamp than simple THD measurements - otherwise we would all be using OPAMPS for everything.
Shoog
You can only speak from personal experience - and my personal experience has been that MOSFET power amps, preamps and headphone amps all shared a similar distinct sound.
The exception I have heard is a MOSFET PA amp which is extremely clean and uncoloured.
As they say - believe what you like.
Shoog
The exception I have heard is a MOSFET PA amp which is extremely clean and uncoloured.
As they say - believe what you like.
Shoog
I would:
1. remove the 470nF input cap and 470k resistor and replace it with decent quality wire, then use 50k Log input potentiometer, keeping the grid stopper resistor.
2. remove the 680uF cathode by-pass cap on the first valve.
3. re-design to remove the 2k7 annode resisitor on the first valve from the signal path.
4. re-design to use a cheep red LED on the cathode of the first valve.
5. re-design to get rid of the 1n4007
6. Consider the use of CCCS
Then I might consider if it wouldn't be worth finding a couple pcc88's and simply build an aikido... 😉
1. remove the 470nF input cap and 470k resistor and replace it with decent quality wire, then use 50k Log input potentiometer, keeping the grid stopper resistor.
2. remove the 680uF cathode by-pass cap on the first valve.
3. re-design to remove the 2k7 annode resisitor on the first valve from the signal path.
4. re-design to use a cheep red LED on the cathode of the first valve.
5. re-design to get rid of the 1n4007
6. Consider the use of CCCS
Then I might consider if it wouldn't be worth finding a couple pcc88's and simply build an aikido... 😉
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