There is no thermal protection, and the Re's of 1ohm are to high (try doing a 'wingspread' on those). The gain is set to 10x, that is a little bit low (I think, e.g. 10 * 1.4V = 14V and the PSU is 24V, so a gain of 15x would be more fitting).
I own this one :Elite Series Quad
For the price it costs it is a very good amp.
I use it as reality check.
For the price it costs it is a very good amp.
I use it as reality check.
Would you care to explain how it works ?
What are those diodes ?
My nobrainer blew one channel (again) when I switched on the manley tube preamp I am working on. (During power on the uge output caps take some time to charge and output offset goes from -10 to + 34v).
Now I must repair it (when I get some more d44 d45h11).
As voltage builds over R3/R4 and gets to Vbe+Vd ( = +- 1.3V) the transistor starts to short (sort of) the base current of the power devices, and directs it into the rail. As you can see this will probably kill the drivers 🙂 (unintentionally, this is not a very good amplifier (as noted before)).
You should not input DC into a DC coupled amplifier! Use a smaller capacitor (that may not work, if the lower frequency is set to 10Hz then the amplifier needs to survive 100mS of the rail voltage into the load) (the load will not like it). Use a output transformer on your pre-amp. Have a relay on the pre-amp that disconnects it from the amplifier as long as there is DC on the output.
In the nobrainer, I have +-1.4v on the bases of the drivers in order to get iddle at 180mA on the output trannies.
In my new simulation, I only need +-600mV to get the same current on the output trannies.
What I need to know is what is the minimum base voltage on the drivers that keeps them conducting.
My questions might seem really basic to most of you guys.... anyway, i found that a CFP needs only around 625mv in the base to start conducting..... so everything is ok for now 🙂
To whom it may concern :http://www.epanorama.net/sff/Audio/Circuits/Pre-Amps/60W NDFL Power Amplifier.pdf
It seems interesting Joachim, here is the ltspice file of the Cherry amplifier , if people want to make some tests.
PS: Q5 have to be renamed BC550C
PS: Q5 have to be renamed BC550C
Attachments
Last edited:
Many thanks.
It is rather simple and trades better in band measurements for a bit less performance over 20kHz.
It is certainly an alternative to TMC for example.
I do not know a commercial amp that uses it.
I think Halcro and Mace adopted some ideas.
It is rather simple and trades better in band measurements for a bit less performance over 20kHz.
It is certainly an alternative to TMC for example.
I do not know a commercial amp that uses it.
I think Halcro and Mace adopted some ideas.
- Status
- Not open for further replies.