Last question first, I think the OP may be misinformed about "monoblocks", which is a very modern usage, and is too young to know the origin of all the -amp terms. In the early days of Hi-Fi (CAPITALIZED for some reason?) the very best system architecture, often DIY, would have a "pre-amplifier" to take the extremely small signals from a tape head or (slightly later) a MM/MI phono cartridge and boost and equalize them up to "line" level of 0.1 to maybe 1.0 volts at peak signal. The pre-amplifier also had switching between these sources and external line-level sources like tuners, complete tape decks, etc. Then a volume control and a gain of 20dB (x10). Usually also tone controls and who knows what else.
This made a signal big enough to drive a "power amplifier", originally mono of course. The power amplifier also provided both the B+ and heater power for the pre-amplifier. In the late 1950s stereo came along and the architecture changed, pre-amplifiers had two channels and their own power supply, in the modern fashion, and power amplifiers had two channels with all but DIY exotica including the two channels' power supply on board. All along, there have been single channel amplifiers used in pairs for stereo, on in other multiples for electronically crossed over speakers, for multi-channel systems, both, etc. that usually have on board power supplies. These have lately gotten a status boost by being called "mono blocks". The only magic is in issues of power supply common grounding, which still has to be dealt with in common PE safety ground issues, so choose yer poison.
Rolling the first two questions into a single personal choice answer, my personal recommendation, FWIW probably not much, would be to start with a simplest possible two stage power amplifier and ignore all discussion of power output. We hear in log, and power output numbers in linear are grossly mis-representative of results. The difference in peak available sound pressure between !0 watts peak and 3 watts peak is 3dB - it's much, much more important for the amplifier to overload cleanly without overhang than to worry about 3dB in the 60dB dynamic range of recorded music listening.
An amplifier without loop feedback around an output transformer, Ishtar willing and the creek don't rise, will run just fine with no adjustments or tweeking. Especially since the OP intends a separate amplifier for power hungry lower frequencies, some two stage design with a common power supply, available (non-trivial right now) output transformers, common current production valves, something linear but in use in geetar amps like 12AX7/ECC83 and 6BQ5/EL84, Hammond or similar output transformers.
I believe deeply in Le Gai Savoir and lifelong learning. But feedback, although actually pretty simple once mastered and very interesting, isn't at all the first thing to try to learn, or even the fifth. Begin at the beginning, Ohm's Law, resistors, capacitors and inductors and how they work, then vacuum valves and a glancing understanding of semi-cons, then circuit architecture. At this point the beauty and artistry becomes visible and the student's passion is ignited. But this work must be done first. The magic will unfold itself at the right time.
All good fortune,
Chris
This made a signal big enough to drive a "power amplifier", originally mono of course. The power amplifier also provided both the B+ and heater power for the pre-amplifier. In the late 1950s stereo came along and the architecture changed, pre-amplifiers had two channels and their own power supply, in the modern fashion, and power amplifiers had two channels with all but DIY exotica including the two channels' power supply on board. All along, there have been single channel amplifiers used in pairs for stereo, on in other multiples for electronically crossed over speakers, for multi-channel systems, both, etc. that usually have on board power supplies. These have lately gotten a status boost by being called "mono blocks". The only magic is in issues of power supply common grounding, which still has to be dealt with in common PE safety ground issues, so choose yer poison.
Rolling the first two questions into a single personal choice answer, my personal recommendation, FWIW probably not much, would be to start with a simplest possible two stage power amplifier and ignore all discussion of power output. We hear in log, and power output numbers in linear are grossly mis-representative of results. The difference in peak available sound pressure between !0 watts peak and 3 watts peak is 3dB - it's much, much more important for the amplifier to overload cleanly without overhang than to worry about 3dB in the 60dB dynamic range of recorded music listening.
An amplifier without loop feedback around an output transformer, Ishtar willing and the creek don't rise, will run just fine with no adjustments or tweeking. Especially since the OP intends a separate amplifier for power hungry lower frequencies, some two stage design with a common power supply, available (non-trivial right now) output transformers, common current production valves, something linear but in use in geetar amps like 12AX7/ECC83 and 6BQ5/EL84, Hammond or similar output transformers.
I believe deeply in Le Gai Savoir and lifelong learning. But feedback, although actually pretty simple once mastered and very interesting, isn't at all the first thing to try to learn, or even the fifth. Begin at the beginning, Ohm's Law, resistors, capacitors and inductors and how they work, then vacuum valves and a glancing understanding of semi-cons, then circuit architecture. At this point the beauty and artistry becomes visible and the student's passion is ignited. But this work must be done first. The magic will unfold itself at the right time.
All good fortune,
Chris
Adriel,
Hopefully you are starting to see the wisdom of Chris' advice. Because I think you didn't understand before why some people wouldn't answer your questions. It probably wasn't because they were trying to keep secrets. Maybe they just didn't think you would understand certain things, that you hadn't prepared enough by learning the basics first? What do you think given what you know thus far?
Hopefully you are starting to see the wisdom of Chris' advice. Because I think you didn't understand before why some people wouldn't answer your questions. It probably wasn't because they were trying to keep secrets. Maybe they just didn't think you would understand certain things, that you hadn't prepared enough by learning the basics first? What do you think given what you know thus far?
Regarding breakpoint diagrams, and poles and zeros, here's how I think about it: If you start from a low frequency and follow a breakpoint line segment towards the next higher frequency breakpoint, one might think of the breakpoint as being like a hinge point or pivot point. If the next like segment is rotated in a clockwise increment around the breakpoint then it a pole. If then next segment is rotated in a counterclockwise increment then its a zero.
There is more to the story of course but for the 'is it a pole or a zero' question, hopefully that may help a little.
There is more to the story of course but for the 'is it a pole or a zero' question, hopefully that may help a little.
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That is a much better description than mine in post #119. So many electrical and electronic things require a fluid transfer in thinking between a Cartesian and a polar model of thinking that I hope the schools are emphasizing this important element today. (I'm only self-taught and more than 50 years ago, so couldn't say.) Bode's stick figures from before the War are still brilliant insights and worth learning for their beauty.
Whoever posted #121 was incorrect: it would properly read that the difference between 10 watts and 5 watts is 3dB. Sloppy, dude.
All good fortune,
Chris
Whoever posted #121 was incorrect: it would properly read that the difference between 10 watts and 5 watts is 3dB. Sloppy, dude.
All good fortune,
Chris
How does this apply? Dad's maternal grandfather was of Dutch and Friesian Mennonite plus some Swiss Quaker heritage, so raised in a frugal and prideless culture. I never said this was my design, even if made changes wouldn't call it mine.
Yes, said that way. However, as I keep asking and get no answer, how is an indent knowledge required to build the amplifier? I understood and again asked for correction and never got it, that once the OPT brand and model were known, R16 then could stay at the specified value and the amplifier could be built. Now based on what you and others are saying, even with knowing the exact OPT, this amplifier still not buildable.
Since it and the Dynaco ST-35 are neither buildable, what else is about 10 watts? European tubes be nice, though if the only option is American, better than nothing!
I tried copying, however, I been informed many times the values of the capacitors and/or the resistors are not correct and the amplifier can't be built. I asked for how to find the value(s), told needed to understand bode plots and poles. I read this, starting to understand, however, have not read or been explained how this information provided the value(s). My fear is since this schematic has produced wonderful results as is, then all schematics must then not have the right capacitor(s) and resistor(s) specified. This makes me wonder how folks are able to buy kits and achieve a successful build. All this seems so illogical.
Thank you for asking this question. 😀 Sadly seems nothing, we got nothing, guess have to move to EL34s (IIRC that is the next step up) and be careful with the volume knob. Not looking forward to starting over, having to have all the capacitor and resistor values evaluated by the forum. However, out toil comes reward.
As the days go by, the generous replies and answers keep coming, I get more and more down.
Just so you are aware, no hard feelings, I was offended by your presumption, I should trust it was an accident. I do know more than supposed. How do I demonstrate my understanding to a list of topics? Examination?
In fact, I have a Magnavox upright console, mono with one speaker, that in the early 1960s gutted by Opa so Oma have additional book storage, as they had bought a nice stereo console (brother threw it out). Have considered stuffing it again, even with a modified turntable and replacement hinges.
If you had read the design criteria and objectives which Richard (@OldHector ) kindly asked for, the big reason for monobocks was the lack of confidence and the ability to test half the design and if there was an issue, be simpler to diagnose and correct. However, with the very limited monoblocks available, I am starting to doubt the validity of this argument.
I will ask this again, where will I get the money for building an amplifier just for learning? If you have something to send, don't mind paying the shipping, done that before a couple times (Volkswagen Beetle parts and a socket turned down for a specific application), be less than eBay (I have been looking).
Okay, supposing have the money, what design should I build that satisfies this criteria?
Thank you for this information, it is appreciated. 🙂
There are two input power supplies since one with the required specifications could not be found, one for the tube heaters and one supplying each monoblock. Based on my vast research (I was sick in bed and bored) it mades a noticeable and significant difference splitting the channels though no significant impact sharing a power supply; please correct me if incorrect.
I have a couple options for the OPTS: go with those used in the Audio Note L1 (this is a clone of it) or deviate from stock with a Sowter. If look at the schematic, the revision of the L1 has added a ultralinear tap, so the only way to achieve this is to go with the latter. This creates more of a mess as there is a 22 percent and a 43 percent. If I had the money, I buy all three versions and try them all out.
Okay. So then stick with the values in the schematic?
Would you please assist me in selecting an OPT or would this be asking too much?
Who said it couldn't be built? And it isn't just R16. Have you noticed C8? Together with R16 they form a filter, and the filter has a time constant. If you multiply R (in ohms) times C (in farads), then the product will be in units of time (seconds). If you change the value of R16, then you may also have to change the value of C8. It depends on what a different transformer would require. How would know what is required? Probably you would have to take some measurements, do some math, estimate the correct value, carefully try it, take more measurements to see if its working as intended or if it needs some adjustment, and so on. You don't know how to do most or all of that stuff yet.
So, its not that the amplifier can't be built, its that you don't yet know enough to take on building it, troubleshooting it, getting it to work properly, and or not killing yourself somewhere along the way. You need some easy projects, you need to start learning basics such as: Ohm's Law, Kirchhoff's Laws, Capacitive reactance, etc. After all that maybe you would be ready to start learning about S. S is the Complex Frequency Variable. Its part of the Laplace Transform which converts functions of Time to functions of S in complex frequency space. This is stuff you would probably learn in your third year of college after two years of math and science classes to prepare you. Chances of you being able to jump into the middle it when you don't even remember algebra are not very good.
People are trying to give you some good advice, but you still don't seem to know enough to be able to see that's its good advice. How do we get that though to you?
I am not sure what he is trying to convey...
Okay, good point for everything, though will respectfully disagree about the plain and simple question regarding the brand and model of OPT (had to ask two times and then not given a direct answer). Supposing I was spoon-fed and given a link, I would not have questioned it, copied the link into the BOM; das ist alles.
I am going to say this the nicest I can, please know I am trying my best to word this so not offensive, don't want to bite the hand that generously feeds! I am wondering why it seems you are the only one with a concern regarding the OPT. Is it because @huggygood didn't confirm that it was the exact one?
Or was that not what you were asking me?
The output transformer in the schematic is specified to have in input impedance, Z in the range of 8k to 10K, and output impedance taps at 6R and 25R. You may find a transformer that is specified to work with two EL84 tubes in a push-pull arrangement. You may also find a transformer with output impedances in more common use today, such as 8R and 16R. Where do you look for such a thing? You start to research that question, maybe something like this: https://www.google.com/search?q=tub...zgKSAQE0mAEAoAEByAEIwAEB&sclient=gws-wiz-serp
EDIT: BTW it has been recommended to you a couple times now that get and read the Valve Wizard book on designing tube preamps. Most of the stages in you amplifier except the final output stage will be explained pretty well. This one: https://www.amazon.com/Designing-High-Fidelity-Preamps-Merlin-Blencowe/dp/0956154530
Have you ordered one yet or discussed your trustee doing it for you?
Some partial info here: https://www.valvewizard.co.uk/
EDIT: BTW it has been recommended to you a couple times now that get and read the Valve Wizard book on designing tube preamps. Most of the stages in you amplifier except the final output stage will be explained pretty well. This one: https://www.amazon.com/Designing-High-Fidelity-Preamps-Merlin-Blencowe/dp/0956154530
Have you ordered one yet or discussed your trustee doing it for you?
Some partial info here: https://www.valvewizard.co.uk/
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I would say it is in large part something more or less like this: Better to start at the beginning, rather than trying to bypass it.
Okay, let us go back and please show me my misunderstanding:
Okay, looking back I see that I was getting folks mixed up, Grover started and then you took over. Still not clear if you two are in agreement regarding the relationship of the feedback loop and the OPT, I did ask you twice and got no answer, even after diagraming. There is a lot going on now so easy to be missed.
What do I need to learn?
How come kits need troubleshooting? In other words, if built as instructed with the parts provided, where would there be an error so great could not be solved with a multi meter? This is a serious question of significant concern.
How would I kill myself by avoiding shock including not taking certain medications?
How are folks been successful by simply buying a kit and assembling? Additionally, @oemcar has twice said absolutely know knowledge is needed, nothing at all. Weird, all this is so confusing...
I doubt it is entirely me, I know my communication ability is basically null. I am listening and asking questions to gain a deeper meaning and they are the ones unable to understand. So I should have taken it face value the amplifier can't be built and walked away? I am going to respectfully disagree as learned so much by questioning it.
I just had the idea to say I think in mostly black and white.
For example, either the amplifier can't be built or now that the OPT has been known it is buildable. Didn't cross my mind until just now that maybe there is something in between: not buildable until I read the required reading, for example.
For example, either the amplifier can't be built or now that the OPT has been known it is buildable. Didn't cross my mind until just now that maybe there is something in between: not buildable until I read the required reading, for example.
Oops, so low blood sugar missed responding to this...
I been hyper focusing on R16 as that is what was the original concern. Fine, add to the mess C8, how does this help?
I will say it again: I am not planning on changing C8 and R16 based on the understanding so long as the correct OPT is used there is no detrimental oscillations. We first need to determine if this is the case or not. If the current values are satisfactory, then das ist alles. If not satisfactory, then I defiantly need to take a step back and learn, then come back and select an amplifier design that does have the OPT fully specified.
Do I need to say it differently so the meaning of my words convey?
I understand. I ask more, however, I am realizing the answer probably is in the book. That was what I originally looking for until told this was not enough information.
I don't see any OPT with this specification, only 4, 8, and/or 16.
Wow! This is interesting, at least two times I said I had and at least once asked for help. Why is it items, be it statements or questions go missing?
"U082 PP output for EL84 UL
8000 ohms Rla-a. 40 W at 20 Hz. 200 mA per side. Also suitable for KT66, 6CA7 etc. Very high bandwidth. Only available in single 6 or single 8 ohms. 10 Hz to 80 kHz. Size P""U064 PP output for EL84 UL
8000 ohms Rla-a. 10W at 30 Hz. 80 mA per side. Choice of 43% or 20% UL taps. 25 Hz to 30 kHz. Size F"Pease observe RG2A and RG2B, thus my concern.
The original: https://www.hificollective.co.uk/catalog/TX-OP-200-1-IE-PP-F.html
"Audio Note push-pull output transformer (as featured in the Old Audio Note Oto amplifier)
Suggested valves - EL84/ECL86/6V6
Max Cl. A Power: 15 w
Primary / Secondary Impedances: 8K / 4 and 8 Ohms
Primary / Secondary wire: copper / copper
Core material - IE"
And @huggygood used a Z=6.000kΩ with the specified values in revision F (schematic provided in post number three). 😳
Not sure how to copy specifications for these two:
https://www.lundahltransformers.com/wp-content/uploads/datasheets/1620_3_7_9202.pdf
https://www.lundahltransformers.com/wp-content/uploads/datasheets/1691.pdf
Oh, is that what it is. Hmmm, again another question to find in the book.
It was? Oh dear...
This isn't the Valve Wizard, I know of this and @Lingwendil provided a copy of both amplifier books, though not the pre amplifier book, so we are clear.
I have not ordered as was told in order to build any amplifier I needed an electrical engineering degree. Is this not true?
Thank you! 🙂 I have read some there in the past.
Where is the beginning?
Re-capping a pair of speakers? Got a set in storage, low quality, they are Jensens.
Maybe try using forum search tool near the top of the page to search this thread for posts by me that mention the string "kirchhoff's" (but without the quotes)
Because you make a bad solder joint, make the wrong connection, the kit contained a bad part, a part was damaged somehow, the kit oscillated when it shouldn't have, the voltage was wrong, whatever. It happens. Part of Heathkit's business was to fix kits that were improperly assembled and or damaged by the buyers.
Haver you ever walked into a room and forgot for a moment why you came there? Ever, even once? Are you always fully alert and focused? When you walk into a room, do you really see everything little thing in the room automatically? Ever misplaced something then found near where you lost it? Or anything similar to the above. Or, are you always without fail aware of everything at all times? If you are human, you have had little lapses now and then where your mind was not focused. Do that with high voltage, and the only thing that saves you may be ingrained habits of following safety practices to the point you just do them automatically, even though you also always have to try to keep focused on safety too.
It depends in part how simple and idiot proof the kit is. It also depends on how well the kit is designed. Haven't people already told you in this thread or your other amplifier thread they don't sell kits because then they have to provide personal support to buyers that costs more money than they can make selling the kits? You think you are special and won't need support? Very likely you will have questions or problems and need some help. You are not experienced enough nor knowledgeable enough yet to figure out such things entirely on your own.
This is interesting from page six, especially the bolded text:
"Rotating transformer cores by 90 (cos 90 .0), so that the coil of one transformer (or choke) not aligned with the other is very effective, and typically results in an immediate 25 dB of practical improvement. Even better, if one coil is driven from an oscillator whilst the interference developed in the other is monitored (oscilloscope or amplifier/loudspeaker), careful adjustment of relative angles can often gain a further 25 dB."
"Rotating transformer cores by 90 (cos 90 .0), so that the coil of one transformer (or choke) not aligned with the other is very effective, and typically results in an immediate 25 dB of practical improvement. Even better, if one coil is driven from an oscillator whilst the interference developed in the other is monitored (oscilloscope or amplifier/loudspeaker), careful adjustment of relative angles can often gain a further 25 dB."