Hi!
Sufficient headroom is not to be confused with sufficient gain! I don't think the D3A would be a good driver. It has enough gain, yes, but would lack headroom.
Best regards
Thomas
Sufficient headroom is not to be confused with sufficient gain! I don't think the D3A would be a good driver. It has enough gain, yes, but would lack headroom.
Best regards
Thomas
Hi:
LL1677 is too expensive to me.
For better result.....
Volume VR connection could try this circuit.
I connect Volume input in this way.
My D/A pre-amp is Hi-Z OPT output.
But sound better than old connection.
Mr211's Blog - Yahoo!?????
LL1677 is too expensive to me.
For better result.....
Volume VR connection could try this circuit.
I connect Volume input in this way.
My D/A pre-amp is Hi-Z OPT output.
But sound better than old connection.
Mr211's Blog - Yahoo!?????
Hi!
The connection of the VC as you showed will present an even higher impedance to the 6C45 grid as the standard one, at lower volume settings it will approach 100k. The 6C45 has a very high input capacitance dominated by miller of a few hundred pF. This will cause high freq roll off well in the audible band.
Also the input impedance of the amp will vary with volume setting, approaching very low values at low volume. Not ideal with a High Z source. Depending on the source that could mean increased distortion.
The fact that it sounds better to you means you like a high frequency roll off which can make a source which tends to sound a bit harsh to appear more relaxed. technically this connection is sub optimal.
A 100k pot driving a 6C45 is already borderline in the standard connection.
Did you check the frequeny response at different VC settings?
best regards
Thomas
The connection of the VC as you showed will present an even higher impedance to the 6C45 grid as the standard one, at lower volume settings it will approach 100k. The 6C45 has a very high input capacitance dominated by miller of a few hundred pF. This will cause high freq roll off well in the audible band.
Also the input impedance of the amp will vary with volume setting, approaching very low values at low volume. Not ideal with a High Z source. Depending on the source that could mean increased distortion.
The fact that it sounds better to you means you like a high frequency roll off which can make a source which tends to sound a bit harsh to appear more relaxed. technically this connection is sub optimal.
A 100k pot driving a 6C45 is already borderline in the standard connection.
Did you check the frequeny response at different VC settings?
best regards
Thomas
Hi:
VC is a carbon trimmer basically is low Q factor component.
After modify circuit I get more detail between 1Khz~4khZ.
That's means audio sensitivity is better than before and
High frequency roll off is not worse as predicted.
That's why some Amplifier no VC setup.
BTW when volume setting approaching very low values at low volume.
Speaker lost more than source input distortion.
Aster
Mr211's Blog - Yahoo!?????
Hi:
feed S.G. signal and use Scop. to measure....No.
-3db bandwidth should be open loop testing
and measurement on scalar analyzer.
I only do Tube amplifier L / R Channel different VC connection test.
After test I choice this connection.
Aster
Mr211's Blog - Yahoo!?????
Hi 811a,
811a is a rough tube, that runs mostly in A2:
App data at 100mA anode current:
Rp: app 26k ohm
GM: app 6000µS
45-65W,
µ: 160 according to data sheet
you will need some FB to get a low output imp for your speakers.
friend of mine run the tube at 65W, with no problems.
best regards
Karsten
811a is a rough tube, that runs mostly in A2:
App data at 100mA anode current:
Rp: app 26k ohm
GM: app 6000µS
45-65W,
µ: 160 according to data sheet
you will need some FB to get a low output imp for your speakers.
friend of mine run the tube at 65W, with no problems.
best regards
Karsten
Hi
The 811A ; I am not sure how well it goes in SE but they are excellent PP.
You need about 600 volts with 2500 Ohms P to P I use 70ma per tube.
Power out put is about 100 watts. The output transformer needs to be very good.
I have used Sowter and Grampian, transformers; about ten kilo's each.
12BH7's /6GU7's and 6bl7's as cathode followers drive them well.
There are several circuits on the net. The amps where mostly used for cutting records.
Phil
The 811A ; I am not sure how well it goes in SE but they are excellent PP.
You need about 600 volts with 2500 Ohms P to P I use 70ma per tube.
Power out put is about 100 watts. The output transformer needs to be very good.
I have used Sowter and Grampian, transformers; about ten kilo's each.
12BH7's /6GU7's and 6bl7's as cathode followers drive them well.
There are several circuits on the net. The amps where mostly used for cutting records.
Phil
Hey dude... from all appearances what you've built is a monkey in size of King Kong... very nice... really... 211 looks like baseball bat hitting the speakers... sound good as hell ... you would've had some nice tooling machines there in Iran cuz they really look like Audionote 211 M.Bs:
An externally hosted image should be here but it was not working when we last tested it.
you let less freakin' chance for bystanders to not get involve in those mono blocks... you know... like sandpaper scratching a green mind
what speakers are they feeding?
Hey dude... from all appearances what you've built is a monkey in size of King Kong... very nice... really... 211 looks like baseball bat hitting the speakers... sound good as hell ... you would've had some nice tooling machines there in Iran cuz they really look like Audionote 211 M.Bs:
you let less freakin' chance for bystanders to not get involve in those mono blocks... you know... like sandpaper scratching a green mind
what speakers are they feeding?
Hi Oldies:
Better connect high sensitivity speaker!
Over 97db like TAD 2402 with horn system.
right a hundred percent ... but I've got something more eminent than that TAD... what about Klipschorn? 3-ways horn loaded... 105dB...
I'd very much like to write some paragraphs about what Aref has built because I was one of the invitees on the demonstration session... you probably want to indirectly imply that inter-stage chokes were bought from abroad... but that's not right... weeks of time spent to twist wiring each by each stride... maximum care has been taking... let's get back to the main issue.. where was I? Oh yeah... testing day ..... to make it understandable I need to go back two months... I just came in sooner, more of the same... Aref just arrived right at time... a polite young man with his friend... two very big and well packed wooden boxes sat on the studio's floor... took some minutes to unwrap them... two recently born infants came outta boxes... looked shining... charming... they were place the the setup and turned on to warm up... after twenty minutes or so the tubes were pretty high...but thinks were about to get even warmer... with the sound...
"Let's get the show on the road" I said and it was checkout time... we were all anxious to begin the sequence of tests... OK... here we go...
first tracks started... sound was just amazing... low-db manger speakers was being handled so well as there was no tomorrow... the volume of sound was pretty high as every man jack would think the roof was just about raining down... sound stage was great literary... I was tied to the chair... I had been given the best seat, front row... center... in the middle of sweet point... we could hear the first fringe touch of the violin arch on the chords... the bass was pretty tight... I have not listened to few sounds... but this one was not a bit but to much different... the timber accuracy of the tubes were just adequate... Manger is so swift... but mono blocks worked the testes out very good... I mean it... really good.
the build quality was eye-catcher... the face was built from plexiglass which laser did the engraving on them... binding-posts were just in the place... gold-plated... tubes were all well-placed... electrostatic painting all over the deck board... a piece of high-quality and darkened wood was dominating looks at the first glance.
all in all it was pretty hoping... nothing wrong... everything was as would be.
someones want to belittle this nice job but I'm afraid, I have to say the reality... even it's a sore one (hey you... I'm talking you... yeah... you yourself )
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