My first reaction was the same as Panelhead's.
You do need a preamp with low output impedance in place of your pot.
Try a very simple project like Bride of Zen and your problem will be gone.
If you still have problems check the PSU caps for leakage. That also is detrimental to sound.
You do need a preamp with low output impedance in place of your pot.
Try a very simple project like Bride of Zen and your problem will be gone.
If you still have problems check the PSU caps for leakage. That also is detrimental to sound.
I use the normal bias !!! I have the pcB from Passlabs....
So, the ZenV4 is not a HI-FI equipment ??? Before to say that, I will make the Bridge Of Zen !!!!
How can I check the power supply capacitor for leakage ???
thank !!!
So, the ZenV4 is not a HI-FI equipment ??? Before to say that, I will make the Bridge Of Zen !!!!
How can I check the power supply capacitor for leakage ???
thank !!!
So your problem is not enough / loud enough? bass? what about testing the Zens sound with larger speakers?
Do you have a soundcard and micophone? could you measure both of your amps through your speakers and post drawings of SPL over frequency?
I feel it is not possible with any amp in the world to get serios bass through small speakers.
Do you have a soundcard and micophone? could you measure both of your amps through your speakers and post drawings of SPL over frequency?
I feel it is not possible with any amp in the world to get serios bass through small speakers.
I haven't built the Zen V4, but if it sounds close to the
Aleph 3 production model i have, then i'd say it has to
be a pretty damn good sounding amp.
I have built the BOSOZ, and i can say that it's the best
sounding preamp i've ever had...
If you're looking for Bass slam, build an Aleph 2 clone...
get your 100 watts and high bias. Don't expect it from
a 25 watt amp with one gain stage.
Aleph 3 production model i have, then i'd say it has to
be a pretty damn good sounding amp.
I have built the BOSOZ, and i can say that it's the best
sounding preamp i've ever had...
If you're looking for Bass slam, build an Aleph 2 clone...
get your 100 watts and high bias. Don't expect it from
a 25 watt amp with one gain stage.
Zen sounds much better with a matching preamp. When I connected it directly to the DAC's output (even without a pot) it didn't sound as good as through the preamp. It is a nice sounding amp, definitely.
I'm not of this king of man who love the bass...
I love music ! I don't care about the bass!
I can make the difference between a "boum boum" system and a hi-fi system !!!
How can I check the power supply capacitor for leakage ???
I love music ! I don't care about the bass!
I can make the difference between a "boum boum" system and a hi-fi system !!!
How can I check the power supply capacitor for leakage ???
Checking Cap leakage
I guess there are several ways to check for this but I will describe the way I do it.
But you have to be very cautious to do this since a lot of current is present and yes it can be letal
The best way is working with two voltmeters. You will need a power supply. This is a trafo of suitable secondary voltage or a variac a diode bridge and a 1K 10W resistor.
You can use the PSU of your amp if you don't have the elements mentioned.
You will have to separate the caps from the amp circuit, yes take them out and test them one by one.
In the case of using the PSU from your amp be sure to disconnect all cables going from the diode bridges to the caps in the ampli.
next connect a wire from the positive side of the diode bridge to one end of the resistor (1K 10W) and the other end of the resistor to the positive terminal of the cap (DUT). Now from the negative side of the diode bridge connect the minus terminal of the cap.
Connect one voltmeter across the 1K resistor and the other voltmeter across the cap (DUT).
Connect your amp to the mains and move the main switch to the on position and monitor the voltages.
you will see a higher voltage at the cap than what you had on the amp since we are not using a load.
Now check the voltage drop at the resistor. For each volt you will have 1 mA of leakege current. A good big cap will be bellow 10 mA usually in the 1 to 5 mA range.
Maintain the connection for one minute, then put off the amp and disconnect from mains.
This is the most dangerous part, to drain the cap after the test.
For this you will need 2 aligator leads and a 100 Ohms 10W resistor. Connect the resistor leads to one end of the leads, now the free ends of the leads are to be connected to the cap.
What I usualy do is connect one of the leads to the negative side of the cap before the test so at the end I only need to connect the plus terminal.
Word of caution
1 Use protection glasses over your eyes.
2 Always work with only one hand over a loaded cap or high power circuit, if you have to.
3 Be sure that the cap is drained before removing it. Use the voltmeter for this. Should read less than one volt.
4 Do not exceed 80% of the voltage rating on the test or application of a cap.
If you don't feel confidence to do this ask someone with the requiered electrical knowledge to perform the test.
I guess there are several ways to check for this but I will describe the way I do it.
But you have to be very cautious to do this since a lot of current is present and yes it can be letal The best way is working with two voltmeters. You will need a power supply. This is a trafo of suitable secondary voltage or a variac a diode bridge and a 1K 10W resistor.
You can use the PSU of your amp if you don't have the elements mentioned.
You will have to separate the caps from the amp circuit, yes take them out and test them one by one.
In the case of using the PSU from your amp be sure to disconnect all cables going from the diode bridges to the caps in the ampli.
next connect a wire from the positive side of the diode bridge to one end of the resistor (1K 10W) and the other end of the resistor to the positive terminal of the cap (DUT). Now from the negative side of the diode bridge connect the minus terminal of the cap.
Connect one voltmeter across the 1K resistor and the other voltmeter across the cap (DUT).
Connect your amp to the mains and move the main switch to the on position and monitor the voltages.
you will see a higher voltage at the cap than what you had on the amp since we are not using a load.
Now check the voltage drop at the resistor. For each volt you will have 1 mA of leakege current. A good big cap will be bellow 10 mA usually in the 1 to 5 mA range.
Maintain the connection for one minute, then put off the amp and disconnect from mains.
This is the most dangerous part, to drain the cap after the test.
For this you will need 2 aligator leads and a 100 Ohms 10W resistor. Connect the resistor leads to one end of the leads, now the free ends of the leads are to be connected to the cap.
What I usualy do is connect one of the leads to the negative side of the cap before the test so at the end I only need to connect the plus terminal.
Word of caution 1 Use protection glasses over your eyes.
2 Always work with only one hand over a loaded cap or high power circuit, if you have to.
3 Be sure that the cap is drained before removing it. Use the voltmeter for this. Should read less than one volt.
4 Do not exceed 80% of the voltage rating on the test or application of a cap.
If you don't feel confidence to do this ask someone with the requiered electrical knowledge to perform the test.
Normal bias? Is that 1.3 or 2 amps? How hot are your heatsinks? I think if both resistors are 0.47 ohms the amp will draw 2.8 amps. The pre-amp will also make a difference. This is the fun part of DIY. Good luck, Mike.😎
Would you consider putting some pics of the inside of your finished Zen 4 and your system and room? It would explain much more I guess.
I don't know if the power supply capacitor or good !!! Do you think it is good to change my two Mallory 37 000uf by two Elna 10 000uf ????
This will make a good modification in the audio quality of the power amplifier ???
The bias is 2 A and after 3 hour of music, the heatsink are very hot... you thick it is better to use more bias??? like 2.8A ???
This will make a good modification in the audio quality of the power amplifier ???
The bias is 2 A and after 3 hour of music, the heatsink are very hot... you thick it is better to use more bias??? like 2.8A ???
Like somebody may have said before ZEN is not for everyone. I’m familiar with several Vifa mid-woofers (and have tried many crossovers) and they are hopeless to ZEN damping capability. Whatever it is, damping factor doesn’t only affect the bass. With Vifa mid-woofers, you can’t expect a hi-fi system with the Zen unless you have a very good line stage. My recommendation is to workout the CDP. Bottlenecks are usually found in the speaker and CDP, not in amplifiers component.
<i>Peter: "Zen sounds much better with a matching preamp. When I connected it directly to the DAC's output (even without a pot) it didn't sound as good as through the preamp. It is a nice sounding amp, definitely."</i>
Peter, I have a different approach. I think a CDP output gain is enough even for such amplifier (Well, of course, the original Zen requires more output swing from the line stage). If it doesn't sound right, then I will make it right. My BOZ is a lot better than anyone's BOZs I have ever compared, still it doesn't qualify to sit between my CDP and Aleph. Yes, I need an extra gain stage, but the added distortion and the problem with some high frequencies in several song with the BOZ (or simply the MOSFET) do not worth the extra detail/gain. I'm in search of a better pre-amp and experimenting with Mullards CV4024s and 12AX7.
<i>Peter: "Zen sounds much better with a matching preamp. When I connected it directly to the DAC's output (even without a pot) it didn't sound as good as through the preamp. It is a nice sounding amp, definitely."</i>
Peter, I have a different approach. I think a CDP output gain is enough even for such amplifier (Well, of course, the original Zen requires more output swing from the line stage). If it doesn't sound right, then I will make it right. My BOZ is a lot better than anyone's BOZs I have ever compared, still it doesn't qualify to sit between my CDP and Aleph. Yes, I need an extra gain stage, but the added distortion and the problem with some high frequencies in several song with the BOZ (or simply the MOSFET) do not worth the extra detail/gain. I'm in search of a better pre-amp and experimenting with Mullards CV4024s and 12AX7.
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