Hello Nico
The Hammond case 1455T2201 do have 220 L x 165 W x 51 H mm
Would you use the 220 mm side for the face plate ?
Because 165 mm side are quite tight to fit all the buttons and switchs.
Bye
Gaetan
Member
Joined 2009
Paid Member
Hello
Here is one extrude and one die-cast aluminium enclosure at Mouser.
The extrude one suggest by Nico, Hammond Electronics extrude aluminium enclosure; $28.74 us
1455T2201 Hammond Enclosures, Boxes, & Cases
And a die-cast one. The Hammond Electronics die-cast aluminium enclosure; $21.34 us
1590D Hammond Enclosures, Boxes, & Cases
Bye
Gaetan
Here is one extrude and one die-cast aluminium enclosure at Mouser.
The extrude one suggest by Nico, Hammond Electronics extrude aluminium enclosure; $28.74 us
1455T2201 Hammond Enclosures, Boxes, & Cases
And a die-cast one. The Hammond Electronics die-cast aluminium enclosure; $21.34 us
1590D Hammond Enclosures, Boxes, & Cases
Bye
Gaetan
Gareth,
This amp is offered only for the purpose of CHOICE. We can have either, but a choice must be made and you play a big part in that.
I have refined it further by halving current through the master device of the CFP, amending bias points and making more measurements. It's now down to a respectable 0.14% H2 (-57.2dB) at 0dB output into 32R, less into high impedances. I have changed the compensation after reviewing the Bode plot, and it's lookin' good, with less phase shift overall, only 2.7 degrees at 20KHz.
The distortion profile is classic monotonic decreasing, with H7 at -137dB, which is pretty good. Output impedance is now 8.2R, a bit better than before. This would work well, BUT, it will give a very different sound to the push pull circuit, a more organic, tubey sound.
The choice of which to use is up to the punters, I'll stay out of it.
Here it is, with simulated measurements:
Cheers,
Hugh
This amp is offered only for the purpose of CHOICE. We can have either, but a choice must be made and you play a big part in that.
I have refined it further by halving current through the master device of the CFP, amending bias points and making more measurements. It's now down to a respectable 0.14% H2 (-57.2dB) at 0dB output into 32R, less into high impedances. I have changed the compensation after reviewing the Bode plot, and it's lookin' good, with less phase shift overall, only 2.7 degrees at 20KHz.
The distortion profile is classic monotonic decreasing, with H7 at -137dB, which is pretty good. Output impedance is now 8.2R, a bit better than before. This would work well, BUT, it will give a very different sound to the push pull circuit, a more organic, tubey sound.
The choice of which to use is up to the punters, I'll stay out of it.
Here it is, with simulated measurements:
Cheers,
Hugh
Attachments
Hi Hugh,
I suggest the 22pF is unnecessary. This amp is very wide bandwidth, distortion is not an issue (0.14% at 2.4V pk) and remains unchanged to about 200kHz before starting to get worse. Phase change at 100kHz is an impressive 0.22 degrees, 0db occurs at 12.5 MHz. This is a nice amp.
I would make the output capacitively coupled with single stabilised supply at 24V, then the bias is not that important and the offset can be a couple of mV here or there.
I used BC547C and BD140-16 in my simulation, I used a 100 ohm resistor as current source, it did not make much difference in the THD at all.
This amp has the potential to be a great amp and I think it is going to be your best sounding amp that you have ever made Hugh.
I will build it up on the week-end when I am home and report back. It is simple enough that anyone can just space wire and try it. Even though I have not heard it, what I see encourages me to ask the guys to sit tight until the week-end. I have a good pair of cans and it does bring out the best in an amp.
I think it will be worth the wait because I can compare the one amp against the other using real live recordings we have made.
Kindest regards
Nico
I suggest the 22pF is unnecessary. This amp is very wide bandwidth, distortion is not an issue (0.14% at 2.4V pk) and remains unchanged to about 200kHz before starting to get worse. Phase change at 100kHz is an impressive 0.22 degrees, 0db occurs at 12.5 MHz. This is a nice amp.
I would make the output capacitively coupled with single stabilised supply at 24V, then the bias is not that important and the offset can be a couple of mV here or there.
I used BC547C and BD140-16 in my simulation, I used a 100 ohm resistor as current source, it did not make much difference in the THD at all.
This amp has the potential to be a great amp and I think it is going to be your best sounding amp that you have ever made Hugh.
I will build it up on the week-end when I am home and report back. It is simple enough that anyone can just space wire and try it. Even though I have not heard it, what I see encourages me to ask the guys to sit tight until the week-end. I have a good pair of cans and it does bring out the best in an amp.
I think it will be worth the wait because I can compare the one amp against the other using real live recordings we have made.
Kindest regards
Nico
Nico,
This is uncharacteristically rhapsodic, are you absolutely sure there is nothing in your baked beans?
Interesting that your simulator, a bought one, gets such different results to mine. I see about 9dB of loop gain at audio frequencies, no more.
I don't have any cans, that's how well set up I am..... we await with knitted brow......
BTW, I use this circuit block in my tube hybrid preamp. The CFP gives voltage gain (4, in this case) while the pentode output stage is configured as a cathode follower. It sounds pretty damn good.
Cheers,
Hugh
This is uncharacteristically rhapsodic, are you absolutely sure there is nothing in your baked beans?
Interesting that your simulator, a bought one, gets such different results to mine. I see about 9dB of loop gain at audio frequencies, no more.
I don't have any cans, that's how well set up I am..... we await with knitted brow......
BTW, I use this circuit block in my tube hybrid preamp. The CFP gives voltage gain (4, in this case) while the pentode output stage is configured as a cathode follower. It sounds pretty damn good.
Cheers,
Hugh
tone control
Hello, I hope I'll not be too much off-topic, but sincerely I'd need an help. I just started a thread on a nikko trm-750 preamplifier with an active, non-inverting topology tone control. Funny to say, I didn't manage to find many information on this circuitry, most of what I've found is in this thread (maybe my fault...).
My question is, is it possible to calculate values for a no more than 10÷12 dB gain line stage, possibly using the 100K antilogarithmic pot used in the Nikko TRM-750 schematic (please give a look at http://www.diyaudio.com/forums/solid-state/154641-nikko-trm-750-a.html thread)?
I don't need too much + or - excursion control, and linearity in tone gain or attenuation isn't an issue, the only thing I need is (obvious) a linear flat curve in pot's middle position (values, in this condition, are shown in the posted schematic).
Sorry for this incursion, I tried a lot, but I haven't the skill to solve this problem by myself, and this seems to be the most active thread where people are discussing this particular tone control topology.
I hope that the already realized Aksa'a spice model can be adapted to simulate the circuit I'm in need of.
Please, please help me!!
Max
Hello, I hope I'll not be too much off-topic, but sincerely I'd need an help. I just started a thread on a nikko trm-750 preamplifier with an active, non-inverting topology tone control. Funny to say, I didn't manage to find many information on this circuitry, most of what I've found is in this thread (maybe my fault...).
My question is, is it possible to calculate values for a no more than 10÷12 dB gain line stage, possibly using the 100K antilogarithmic pot used in the Nikko TRM-750 schematic (please give a look at http://www.diyaudio.com/forums/solid-state/154641-nikko-trm-750-a.html thread)?
I don't need too much + or - excursion control, and linearity in tone gain or attenuation isn't an issue, the only thing I need is (obvious) a linear flat curve in pot's middle position (values, in this condition, are shown in the posted schematic).
Sorry for this incursion, I tried a lot, but I haven't the skill to solve this problem by myself, and this seems to be the most active thread where people are discussing this particular tone control topology.
I hope that the already realized Aksa'a spice model can be adapted to simulate the circuit I'm in need of.
Please, please help me!!
Max
Member
Joined 2009
Paid Member
Well I'm a known fan of the CFP so I have no objections to the SE design, all the better if it will be prototyped first. My current DIY projects are all CFP output too - the first one will be SE so I can hardly argue with the direction that the headamp is taking can I ?
The sudden SE deviant was surprising, but it has my full support. I kinda feel sorry for Bigun though... He seems to be under pressure.
It doesn't have to come at the cost of high THD:
http://www.diyaudio.com/forums/solid-state/146346-cfp-gain-stage-modifications.html
And I think we could optionally include a "monotonic distortion" knob...
I believe the AB design would have more dynamic range, better reproduction of drums and percussion?
- keantoken
It doesn't have to come at the cost of high THD:
http://www.diyaudio.com/forums/solid-state/146346-cfp-gain-stage-modifications.html
And I think we could optionally include a "monotonic distortion" knob...
I believe the AB design would have more dynamic range, better reproduction of drums and percussion?
- keantoken
Member
Joined 2009
Paid Member
I kinda feel sorry for Bigun though... He seems to be under pressure.
It's true, I deserve an easy life with sunshine, wine and music
Hello Hugh
39C in spring season !
That's why there is so much good amps designers in Australia... your spring and summer seasons are working in class A
Your Diyaudio Aspen Amplifiers banner look great.
Bye from cold Quebec
Gaetan
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