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Post by Deleted on Feb 25, 2010 10:13:58 GMT
As said the first one is a concept where you can shoot at. Properties UNKNOWn as it is NOT built yet (clearly stated in the design b.t.w.) You do not have to love tubes (I just build one because I was curious) to have constructive comments instead of dismissing it and pissing on it .. It's a JAHHA idea. (Just Another Hybrid Headphone Amplifier ) Sort of a bridge between tube and SS intended for INTERESTED people (so Not Alex perhaps . If you prefer SS over tubes and have no CONSTRUCTIVE input to give then you'd better browse through other threads and scare other people. Robert Started it because I suggested it in the Bravo thread ... and that's just what we are trying to do follow up and keep the Bravo thread clean. NOT claiming it is better/the best... just trying to make another cheap hybrid. Ian is right though ... it will be more expensive to build. We can't compete with the Chinese on a FINANCIAL base. You can insert the CCS part (first schematic) in an existing Bravo/Indeed though. Will stabilise the 16V anode voltage without a doubt. The schematic below isn't Alex's favorite either perhaps (as he didn't design it ) ... at least it doesn't include those inferior horrible glass trashcans ;D but this thread is about JAHHA (whether YOU like 'm or not.. other people MIGHT)
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robertkd
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Post by robertkd on Feb 25, 2010 10:21:44 GMT
Geez, Robert. Why didn't I think of that ? What better way to illustrate the difference between valve amps and a good SS design, than have a 12AT7 in one channel, and a 12AU7 in the other channel !!! ;D Alex They where the first 2 I came to out of my box of goodies and for illustration purposes only, besides it will likely likely end up 12AU7's or 6922's ;D
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Post by clausdk on Feb 25, 2010 10:31:50 GMT
This being Rockgrotto and a lot of us have very nice hybrids (Xcans), why not a SS or tube..
I would love to make a tube-amp, they look so nice glowing it the dark..
If we could make one Alex liked, we would be onto something BIG . .
A variation of the DV ??
Carbatteries for power ?? would that be feasible ?
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Post by Deleted on Feb 25, 2010 10:37:33 GMT
Frans I was merely saying that I preferred your original design with the better CCS, and 70V HT vs. 24V . I did not piss on it , or dismiss it. I took the cue from your use of the word SHOOT, in an attempt to inject a little humour. I guess that backfired on me ? Obviously, the parts count of your original design is much higher too. I gather then, that the new design was just put to paper, and not SIMULATED first , as many seem to do these days . Alex Was that REALLY necessary ? O.K. I am out of this thread now.
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robertkd
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Post by robertkd on Feb 25, 2010 10:40:53 GMT
Interesting adding a bit of blending um cross feed, Frans I see you kinda like these buf634's Nah Alex has probably forgotten more about tubes then I know
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robertkd
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Post by robertkd on Feb 25, 2010 10:49:29 GMT
frans problem did you intend tou use both filaments?? I seem to recall the filaments used like that in the millet starving student design, it's a nice way to dump half the supply voltage and at least not waste it as were. www.pmillett.com/starving.htm
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Post by Deleted on Feb 25, 2010 10:58:07 GMT
Robert I would never claim something like that. However, if you had to test as many valves, and replace as many valves in "singing"/unstable/dead Carrier channel amplifiers as I had to, you would be happy to forget about them too ! Alex
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Post by Deleted on Feb 25, 2010 10:58:22 GMT
@ Alex, I'm not mad. I knew what you meant LOL Like you I believe the 70V anode voltage and temp stable CCS is 'better' but if it is to be something built in kit form I wouldn't want to kill people with 100V+ jolts so used the safer low 'Bravo' voltage in this design.. the first design is a more 'stable' variation on the Bravo/Indeed theme. The second (built) design I came up with because of the (IMHO) flawed Bravo/Indeed design on certain aspects. Doesn't mean people can't love the sound from these devices. They might even prefer it over schematic 1 AND 2 for all I know. Not simulated... not build... indeed just a quick drawing of a concept. ;D BUF634's do the job as well as others can IMHO. a bit of a pain to get them not to start ringing or oscillating on vero board. Have BUF's and the used op-amps in my stock ... that's why I use them not because they are 'better' ... a matter of convinience. Waiting to hear if Techs like to see things changed (in the concept schematic) or have good suggestions (Alex may join in also ) Yes .. series tube filaments because I have a nice 12V anyway. Will limit the tubes when rolling... the class A current would be half that of a parallel (+ LM317) BUT the sourcefollower has feedback which will compensate.
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robertkd
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Post by robertkd on Feb 25, 2010 11:47:04 GMT
You know I'm still keen to go with maybe +/- 25V (ish)but that's me ;D
I'm a little lost at the CC arrangement?
Also if your going to use the 2 filaments, might as well run the 2 triodes on parallel and run one tube per channel.
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Post by Deleted on Feb 25, 2010 12:21:14 GMT
Good idea running them parallel but 1 tube would save building costs.
Running at +/- 25 volts is a good idea but Opamps will let out the magic smoke again.. (+/- 18 Volt about max)
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robertkd
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Post by robertkd on Feb 25, 2010 12:52:06 GMT
Yeah I know I'm still trying to keep it simple.
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Post by guadixman on Feb 25, 2010 15:34:24 GMT
Has everyone got their head stuck up their respective (or other peoples) arseholes.
WAD HD83 - the EL83 tube was designed at the end of the 1950s for television. It was designed with wide bandwidth for the picture and any audio qualities are by the by.
It is a pentode which is why WAD decided to use it as opposed to a triode, reason - far more voltage gain and power output than a triode - amongst other things and of course because it was cheap and easy to source in the UK.
Take a look at Broskies 'super triode' idea and the 6SN7 - so many different flavours to choose from and inheritantly better than a pentode, I should know.
I have an EL34 (pentode) and KT88/6550 amps. I love the EL34 amp but it simply does'nt have the finesse and linearality of the triode - BTW the St.Petersburg Svetlana EL34/KT88/6550 tubes are way better than the NOS Mullards, lots of xenophobic bullshit is talked about Mullard tubes - they were'nt always that good and many are very microphonic.
So using the HD83 as a start point, think 6SN7. What else - look at the layout of this h/amp, not really any different from many other h/amps - think out of the box (for some totally impossible).
So what's wrong - first always a bad idea to have the pot/att. at the front of the amp, likewise the on/off switch. By using an extension rod and an ali plate to hang the pot./att. off, the signal wires can be less than 1 inch.
Having the mains tx right next to the o/put txs another very bad idea - why not make it a 2 box affair - mains tx and PSU in one box joined by a piece of shiny copper pipe to carry the cables. A steel box is not a good idea and silly when you can buy simple alu boxes from Maplins very cheaply.
With a two tube amp it is very important to have matched tubes (have you done that Mike.
The HD83 would be far better with a more powerful mains Tx essential in a tube amp and much better quality o/put txs. PSU caps contrary to what some uninformed think are always better for being over-voltaged - it's called headroom.
Nothing wrong with PCBs that are made up to a quality not down to a price but really much better to build point-to-point, so much easier to (1) try different components and (2) if the case has been designed properly much easier to dissipate heat.
Having now finished modding the Bada PH12, I would say - think about designing a hybrid h/amp. Mosfets are much cheaper than using o/put txs.
There seems to be a mentality on this forum that cheap is good - it is'nt and you simply cannot have outstanding sonics without using quality components. The way to prove this is to design the amp (carefully) and then let the tightwads built it for pennies and those who build upto a quality do so and then stand back and laugh at the cheapskates.
The beauty of a design like the HD83 is that it uses very few components, so no excuse for not putting some tried and tested quality components in.
Someone wants to use op-amps why - don't most of you have op-amp h/amps - so why bother to re-invent the wheel.
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Post by Deleted on Feb 25, 2010 16:20:04 GMT
Just trying to make a small nice sounding amp based on the Bravo indeed without the lethal voltages of 'normal' tube amps.
It's just a concept..
AGAIN I am not telling this is better... just for the fun of making a cheap good sounding hybrid amp.
NOT to reinvent the wheel ... that would be pointless ...
Seeing how people rave about the sonics of the Bravo amp and the HD681 it is proven that good sonics CAN be had for a low price.
Why not give it a go and have solid constructive advise and post an alternative schematic .. ?
I don't believe my head nor any other part of my body is up mine or someone else's ... b.t.w. Why on earth would I ?
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Post by MaN227 on Feb 25, 2010 20:54:19 GMT
I think its great what you are trying to do here solderdude, I really do. I hope others can try to help , interact and discuss the many possibilities. As it seems lately here (in the RG), there is a sort of battle of wills, finger pointing and an out and out superiority complex or some sh!t. I personally think if everyone would speak to others as though they were FACE to FACE, then perhaps we could curb the nonsense. I have visited this forum off and on for a few years now (as my joined date shows <-------------). I have never seen such behavior as I have just here recently. consider this. If one is never OFFENSIVE than there is no need for yourself or others to be DEFENSIVE. Do unto others man, as you would like done to you. keep on going solderdude and all you folks of knowledge. oh and play nice. If anyone feels like making it personal with me, please feel free to PM me, and I shall oblige your desires Peace
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Post by Deleted on Feb 25, 2010 21:38:46 GMT
man227 Try not to read so much into the forcefully expressed opinions of some of the members here. (especially myself) Actually there is a large degree of agreement in many areas ,despite what it may appear on the surface. Quite often there is also a great deal of friendly contact via emails and PMs that others do not get to see. Sure, we do have small areas of disagreement, but in the vast majority of cases, they are only minor. Despite what it may look like here, as an example, Frans and myself have many areas of general consensus, even down to our tastes in music ! Robert and myself are in broad agreement in most areas, and I have also learned a little more by reading what both he and Rick have to say as well. Robert was instrumental in me increasing the supply voltages of the Class A HA from +-15V to +-20V, although it took me quite a few months to get around to it. Robert was correct when he said there would be a further improvement. We all have a little to learn from each other. Just don't ask me to try a valve amplifier design again, as I first built a valve amplifier in a Postmaster General's Department training school in Sydney 1955, followed by several others later on ! SandyK
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leo
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Post by leo on Feb 25, 2010 21:47:58 GMT
These group type projects never really work, somebody just has to pull the trigger and do something then post some pictures of the thing once its finished
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leo
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Post by leo on Feb 25, 2010 21:54:36 GMT
If the guys wanting to sort these RG amps are really serious why not just do something like a poll to get some idea what most folks want
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Post by Deleted on Feb 25, 2010 22:08:33 GMT
These group type projects never really work, somebody just has to pull the trigger and do something then post some pictures of the thing once its finished Leo The problem there is that to do it properly, there is a huge numbers of man hours involved, as well as the expense. Then the designer ,if he has built something that he feels many members may want, is left with something that is then going to be shoved into the back of a cupboard, or stripped for spares. It would be frustrating for someone to do something like this in their valuable spare time, to then only have a couple of units actually constructed. Alex
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Post by leo on Feb 25, 2010 22:16:28 GMT
looks like its back to ebay for you guys
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Post by Deleted on Feb 25, 2010 22:19:00 GMT
looks like its back to ebay for you guys Another Indeed/Bravo? It's cheaper. Ian
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Post by PinkFloyd on Feb 25, 2010 22:24:38 GMT
These group type projects never really work, somebody just has to pull the trigger and do something then post some pictures of the thing once its finished Yup.... my thoughts entirely Leo which is why I am not getting involved in any of these threads. No one person will agree on anything and, if they do, a compromise will be made to let the other guy "add" his part of the circuit into the mix...... so on and so forth..... you'll end up with an all singing all dancing wankfest with more "options" than a call to DELL computers ;D There are a lot of talented guys here and I would rather see them each design their own amp and put it to the members for evaluation.... these "group" efforts are a total waste of time IMO. Mike.
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Post by Deleted on Feb 25, 2010 22:39:30 GMT
It's only a waist of time if you don't participate.
Too bad ... I had given you more credits
But your'e right on this aspect (waist of time) I assume as there are only 3 or 4 suggestions efforts so far. have only been living in the Grotto for a month or 2 and figured most people where as serious about Audio as I was.
I hate universal devices and believe in dedicated things and would not design an all options wankfest thingy.
If you want this attempt to stop just say so Mike and not question my motives or knowledge but use plain English and EXPLAIN
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Post by Deleted on Feb 25, 2010 22:53:15 GMT
It's only a waist of time if you don't participate. Too bad ... I had given you more credits But your'e right on this aspect (waist of time) I assume as there are only 3 or 4 suggestions efforts so far. have only been living in the Grotto for a month or 2 and figured most people where as serious about Audio as I was. I hate universal devices and believe in dedicated things and would not design an all options wankfest thingy. If you want this attempt to stop just say so Mike and not question my motives or knowledge but use plain English and EXPLAIN~ Frans Would it be possible to quickly throw together your revised circuit, and perhaps send the end result to Mike or another person who already owns one for evaluation ? It would be a shame to go to a lot of trouble if the end result didn't make the owner want to change to your version, no matter how much better it was technically. Alex
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Post by Deleted on Feb 25, 2010 23:08:01 GMT
I would have to make time for it.
When you make something on protoboard the end design on PCB might differ for the better or worse.
It seems you can only be considered serious when you have lived in the Grotto for a long time AND must be a believer.
Am neither.. just know about electronics and Audio and like to do something for people.
I just was naive to think that an effort would be made to put in real ideas and make it work. There seems to be little interest in that apart from a few members.
Like the way Chaz (the newbie in this forum) thinks... much like me.
Thought these forums where about helping each other out instead of pissing on ideas someone else might have.
I do believe I have made some nice friends in the Grotto (you too Alex although in the forums it doesn't look that way) and cherish that.
I will consider your suggestion. But it's a big gamble sending something to Mike for evaluation when his mind about me seems to be made up already... But then again he might surprise me and think he is kind too ... just a bit blunt now and then and makes a lot of assumptions ..
Too bad that there is NO CONSTRUCTIVE input efforts of those that claim to have 'THE KNOWLEDGE'
Yeah I know the answer...
It's pointless mate ... everybody has different views and already has one or more good amps.. ;D
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Post by clausdk on Feb 25, 2010 23:16:17 GMT
Send it to me, I do not have an indeed, but I have other good stuff lying around..
And since I do not have any idea what you guys are talking about, I have no side in this..
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