I've also ordered a relvol3, input2 and supporting bits from Dantimax. Looks like a it should be a nice bit of kit :0
I've also discovered some nice looking ERO caps that I'm tempted to use on the p1.7. They are a 12uF/100V mkt1813. I'm a bit put off by the fact that they are MKT but they seem to be a couple of notches above the run of the mill MKT's, being a rolled axial cap. A quick google turns up references to them being a good quality bypass/coupling cap in tube amps, and a couple instances of them being used in the signal path for cd player/tuner upgrades. They are just small enough to squeeze on the boards. Anyone know if they are worth considering?
At worst they could be a decent stop gap until the end of year mayhem subsides and I have a chance to order some BG N's.
thanks
Paul
I've also discovered some nice looking ERO caps that I'm tempted to use on the p1.7. They are a 12uF/100V mkt1813. I'm a bit put off by the fact that they are MKT but they seem to be a couple of notches above the run of the mill MKT's, being a rolled axial cap. A quick google turns up references to them being a good quality bypass/coupling cap in tube amps, and a couple instances of them being used in the signal path for cd player/tuner upgrades. They are just small enough to squeeze on the boards. Anyone know if they are worth considering?
At worst they could be a decent stop gap until the end of year mayhem subsides and I have a chance to order some BG N's.
thanks
Paul
I just received my boards from Dantimax, it looks like a lot of work to mount al the parts and to compare all boards, trust me!!!
I want my (balanced, RelVol3) volumecontrol on the output of the Aleph P1.7 cone, and i ordered the volume-kit with 1K restistance.
but now i doubt: is 1K the right value? i read many other values on this forum. Is there anybody woho can advice me about this?
I want my (balanced, RelVol3) volumecontrol on the output of the Aleph P1.7 cone, and i ordered the volume-kit with 1K restistance.
but now i doubt: is 1K the right value? i read many other values on this forum. Is there anybody woho can advice me about this?
Original value on the output is 2k so you are very close 🙂
It is proberly alright to use 1k.
/Z
It is proberly alright to use 1k.
/Z
Hi Wim!
I think so either, because I can do it with 10K, but 5 would be better and I think also 1 K should do the job, so give it a try, and you will find out! Grtz Teake.
I think so either, because I can do it with 10K, but 5 would be better and I think also 1 K should do the job, so give it a try, and you will find out! Grtz Teake.
Thanks. I decided to go for a 1K resistance. Christmas-time......, not many time to spent on electronics, but i will inform you about the progress with the Dantimax kit's.
Hissing p1.7
I've got the psu and main boards for my Aleph P done and I seem to have struck some trouble with audible hiss. I've spent the evening trying various grounding and wiring strategies without success.
I've stripped back to basics and have a balanced connector on the output and the +/- inputs shorted to ground. With this arrangement there is a distinct low level "white noise" audible from the speakers - this is audible to about 50cm from the speaker. If I disconnect the + input from ground the hiss drops to a very low level - audible maybe 10cm from the speaker.
I've also discovered that if I move the dip switches from a "both forward" (open??) position the hiss increases substantially audible about 1m+ from the speakers. I've tried jumpering across the protection zeners but than didn't seem to make any difference.
At this stage I'm stumped and would welcome any advice...
cheers
Paul
I've got the psu and main boards for my Aleph P done and I seem to have struck some trouble with audible hiss. I've spent the evening trying various grounding and wiring strategies without success.
I've stripped back to basics and have a balanced connector on the output and the +/- inputs shorted to ground. With this arrangement there is a distinct low level "white noise" audible from the speakers - this is audible to about 50cm from the speaker. If I disconnect the + input from ground the hiss drops to a very low level - audible maybe 10cm from the speaker.
I've also discovered that if I move the dip switches from a "both forward" (open??) position the hiss increases substantially audible about 1m+ from the speakers. I've tried jumpering across the protection zeners but than didn't seem to make any difference.
At this stage I'm stumped and would welcome any advice...
cheers
Paul
Hissing p1.7
I've got the psu and main boards for my Aleph P done and I seem to have struck some trouble with audible hiss. I've spent the evening trying various grounding and wiring strategies without success.
I've stripped back to basics and have a balanced connector on the output and the +/- inputs shorted to ground. With this arrangement there is a distinct low level "white noise" audible from the speakers - this is audible to about 50cm from the speaker. If I disconnect the + input from ground the hiss drops to a very low level - audible maybe 10cm from the speaker.
I've also discovered that if I move the dip switches from a "both forward" (open??) position the hiss increases substantially audible about 1m+ from the speakers. I've tried jumpering across the protection zeners but than didn't seem to make any difference.
At this stage I'm stumped and would welcome any advice...
cheers
Paul
I've got the psu and main boards for my Aleph P done and I seem to have struck some trouble with audible hiss. I've spent the evening trying various grounding and wiring strategies without success.
I've stripped back to basics and have a balanced connector on the output and the +/- inputs shorted to ground. With this arrangement there is a distinct low level "white noise" audible from the speakers - this is audible to about 50cm from the speaker. If I disconnect the + input from ground the hiss drops to a very low level - audible maybe 10cm from the speaker.
I've also discovered that if I move the dip switches from a "both forward" (open??) position the hiss increases substantially audible about 1m+ from the speakers. I've tried jumpering across the protection zeners but than didn't seem to make any difference.
At this stage I'm stumped and would welcome any advice...
cheers
Paul
Is you "master" volume on the input or on the output ?
Also how is your Bias set? (the 2k trimpots)
Any photos of the assembled boards could help also.
Do you mean that you have grounded both + and - on the input ??
/Z
Also how is your Bias set? (the 2k trimpots)
Any photos of the assembled boards could help also.
Do you mean that you have grounded both + and - on the input ??
/Z
Maybe i am understanding you wrong but...
You should,nt have both + and - grounded. For SE use, only - is to be grounded.
For balanced use, neither + or - should be grounded.
When using a master volume on the Input instead of the Output ( like in the original) a little bit more noise is noticed from the Mosfets. Not much but i guess audieble with senstive speakers.
The DIP switches is to alter the Gain on the input, 12 dB attenuation according to the manual.
Let us know what is happening. 🙂
/Z
You should,nt have both + and - grounded. For SE use, only - is to be grounded.
For balanced use, neither + or - should be grounded.
When using a master volume on the Input instead of the Output ( like in the original) a little bit more noise is noticed from the Mosfets. Not much but i guess audieble with senstive speakers.
The DIP switches is to alter the Gain on the input, 12 dB attenuation according to the manual.
Let us know what is happening. 🙂
/Z
Hi Zei,
I've been testing the boards as a buffer to my passive pre-amp, so I have had short leads with RCA plugs attached to the input side and wire to +/GND and a jumper from GND/-. I was concerned that the 10cm unshielded twisted leads could have been causing the problem so I have temporarily removed them and was testing with the + input open or shorted to GND. Shorting + to GND seems like a fairly common method for testing for ground loops etc.
Anyway the outcome of this seems to be that the leads are not causing the problem.
I currently have the 10K pot in my passive at the input, but this is a temporary setup. I have a 1K RELVOL 3 on order from Mikkel @ Dantimax but he was waiting on delivery of a PLED module before sending the parcel out when I spoke to him before xmas.
I have both 2K trimmers set to minimum output, adjusting the trimmers has no appreciable effect on the level of hiss, but I did notice some pot noise when adjusting the trimmers last night. I'd assumed that these were the same as L/R gain and should be adjusted towards minimum as per user manual?
My speakers are claimed to be 90db (1w/1m) which isn't overly sensitive but maybe I'm just hearing MOSFET noise? It just doesn't seem to correlate the reports of these boards being dead quite. I'm also suspicious that altering the dip switches from "both open" generates such high levels of hiss. It just doesn't seem right.
Apart from the hiss the boards sound pretty sweet, even running as a buffer, the gains over the passive alone are quite impressive. I'm sure the imaging is more solid and there is far more detail in the bass.
Cheers
Paul
I've been testing the boards as a buffer to my passive pre-amp, so I have had short leads with RCA plugs attached to the input side and wire to +/GND and a jumper from GND/-. I was concerned that the 10cm unshielded twisted leads could have been causing the problem so I have temporarily removed them and was testing with the + input open or shorted to GND. Shorting + to GND seems like a fairly common method for testing for ground loops etc.
Anyway the outcome of this seems to be that the leads are not causing the problem.
I currently have the 10K pot in my passive at the input, but this is a temporary setup. I have a 1K RELVOL 3 on order from Mikkel @ Dantimax but he was waiting on delivery of a PLED module before sending the parcel out when I spoke to him before xmas.
I have both 2K trimmers set to minimum output, adjusting the trimmers has no appreciable effect on the level of hiss, but I did notice some pot noise when adjusting the trimmers last night. I'd assumed that these were the same as L/R gain and should be adjusted towards minimum as per user manual?
My speakers are claimed to be 90db (1w/1m) which isn't overly sensitive but maybe I'm just hearing MOSFET noise? It just doesn't seem to correlate the reports of these boards being dead quite. I'm also suspicious that altering the dip switches from "both open" generates such high levels of hiss. It just doesn't seem right.
Apart from the hiss the boards sound pretty sweet, even running as a buffer, the gains over the passive alone are quite impressive. I'm sure the imaging is more solid and there is far more detail in the bass.
Cheers
Paul
Hey Paul, it seems that you ordered exactly the same stuff from Dantimax as i did (Input2, control2 and relvol3).
I am goint to use the relvol3 on the output off the amp and i ordered 1K restistors for it.
Were do you plan to use your relvol3? Input or output?
I destroyed my LCD display, so i am waiting for another. The boards are ready and with the display i can test the whole thing.
In a few days i shall post a picture off all the boards i am going to use and the (not finished) enclosure that i want to use.
I am goint to use the relvol3 on the output off the amp and i ordered 1K restistors for it.
Were do you plan to use your relvol3? Input or output?
I destroyed my LCD display, so i am waiting for another. The boards are ready and with the display i can test the whole thing.
In a few days i shall post a picture off all the boards i am going to use and the (not finished) enclosure that i want to use.
Hi Wim,
certainly looks like we did... I'm looking forward to getting my parcel from Mikkel 🙂
The 1K will work best at the output as per the original p1.7. Sorry to hear you destroyed the LCD 🙁
In my continuing hunting of the hum I realised that the manual switch settings and Veterans switch layout need some translation. I've compared the service manual number and veterans schematic I think I'm on track now. The switch settings I had used were "non-settings" and while the hum still remains now it is at very low (and acceptable for the moment) levels.
In the attached graphic the dB figures refer to gain (as per service manual). To map the settings described in the user manual:
default = 15dB
12db attenuation = 1.3dB
hope this helps someone 🙂
cheers
Paul
certainly looks like we did... I'm looking forward to getting my parcel from Mikkel 🙂
The 1K will work best at the output as per the original p1.7. Sorry to hear you destroyed the LCD 🙁
In my continuing hunting of the hum I realised that the manual switch settings and Veterans switch layout need some translation. I've compared the service manual number and veterans schematic I think I'm on track now. The switch settings I had used were "non-settings" and while the hum still remains now it is at very low (and acceptable for the moment) levels.
In the attached graphic the dB figures refer to gain (as per service manual). To map the settings described in the user manual:
default = 15dB
12db attenuation = 1.3dB
hope this helps someone 🙂
cheers
Paul
Attachments
Well maybe I should say one channel is working fine. 
The other channel has gone to the dogs :\
DC bias voltage over the input on the working channel is 12.9V on +/-. On the noisy channel I'm getting 10.0/8.0 respectively -- not good.
I'm hoping I haven't fried some MOSFETS in my "troubleshooting" endeavors.
The other channel has gone to the dogs :\DC bias voltage over the input on the working channel is 12.9V on +/-. On the noisy channel I'm getting 10.0/8.0 respectively -- not good.
I'm hoping I haven't fried some MOSFETS in my "troubleshooting" endeavors.
This is doing my head in.... Powered up the dodgy channel and remeasured dc bias over the input caps - 13.2V. So that seemed fine. Voltage drop over 22.1 and 33.1 resistors 0.59V which is about right. I hooked up to the amp and noticed that the gain switches were now functioning correctly and hum about the same as the other channel and very low level. There was a scratchy sound - like a bad pot being turned which went on for a few minutes before the channel made a dull thump sound and the high level hiss returned. Remeasured the dc bias and this had returned to the 10/8 previously noted.
I clearly have a faulty component or solder join somewhere, but if anyone can suggest which parts I should check first that would be very much appreciated.
cheers
Paul
I clearly have a faulty component or solder join somewhere, but if anyone can suggest which parts I should check first that would be very much appreciated.
cheers
Paul
I seem to have sorted the problem?? fingers crossed. replaced all the ztx trannies to no avail. while testing I noticed that the when in the fault state the board was very microphonic and a tap on the board could be heard as a loud thud at the speakers. I've double checked the solder joins and wicked off any that didn't look 100% and resoldered. That seems to have fixed the problem and I have similar levels of faint hiss on both channels. I'll reassess when I have the dantimax boards installed but I think it should be fine as is.
cheers
Paul
cheers
Paul
xlnt trouble shooting! glad it finaly works. try your pot on the output if you have the chance and i,m shure the last hizz is going away aswell.
writing on my phone from the buss so sry for spelling etc..
/z
writing on my phone from the buss so sry for spelling etc..
/z
well I think I spoke too soon. The problem is still there but seems to take much longer to happen. I have suspicions it is the MKT1813's I'm using. A couple are extremely microphonic: of the 6 installed 2 cause loud bangs on the speakers when tapped. One of the output caps is particularly bad, so I guess I'm not going to waste money on these in future. I'm fairly sure this behavior is not the sign of a good cap 😉
I've put in an order for a set of BG N's but that will be a few weeks before I see them.
update: I've swapped out the MKT1813 output caps for a pair of 56uF panasonic HQF with 100nF MKP bypass caps. Doesn't sound as good but seems to have calmed the scratchiness and microphonics for the moment. They might have to do until the BG's arrive.
cheers
Paul
I've put in an order for a set of BG N's but that will be a few weeks before I see them.
update: I've swapped out the MKT1813 output caps for a pair of 56uF panasonic HQF with 100nF MKP bypass caps. Doesn't sound as good but seems to have calmed the scratchiness and microphonics for the moment. They might have to do until the BG's arrive.
cheers
Paul
spzzzzkt
Seems like you found the source to your problems then?
It might be ( have been) a mix of things as well, a bad soldering, caps etc..
I noticed a faint hizz at the first few hours my self, but that has almost completly dissappered now. By it self. Don,t ask me how. .maybe i have a bad soldering somewhere as well.
The very small hizz i can hear now (only on loud volumes with no music playing) is proberly mosfet noise..
Keep us updated and put up up some pictures! 😎
/Z
Seems like you found the source to your problems then?
It might be ( have been) a mix of things as well, a bad soldering, caps etc..
I noticed a faint hizz at the first few hours my self, but that has almost completly dissappered now. By it self. Don,t ask me how. .maybe i have a bad soldering somewhere as well.
The very small hizz i can hear now (only on loud volumes with no music playing) is proberly mosfet noise..
Keep us updated and put up up some pictures! 😎
/Z
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