I just got in the Charlize PCB - waiting for the aluminum case I ordered to come in. The rest of the parts will come from my collection of stuff I have accumulated making tube preamps/amps over the years.
I'm actually getting pretty geeked about this project - and hope I can retire my heavily modified Dynaco 70.
Has anyone noticed a big difference between a battery and switching power supply? I was initially going to use a battery - I've been real pleased with the sound of my Monica 2 DAC running on a SLA versus a linear power supply. Is the Charlize equally sensitive to power supplies?
I'm actually getting pretty geeked about this project - and hope I can retire my heavily modified Dynaco 70.
Has anyone noticed a big difference between a battery and switching power supply? I was initially going to use a battery - I've been real pleased with the sound of my Monica 2 DAC running on a SLA versus a linear power supply. Is the Charlize equally sensitive to power supplies?
I've read as much as I can find regarding input / output impedance, but still have a few questions specifially regarding the Monica2 and Charlize combo.
What exactly is the output impedance of Monica2 and the input impedance of Charlize?
The diyparadise article about the grounded grid tube gain stage, this statement indicate Monica2 should see a "lower" input impedance:
"Now GG works better than common cathode gain stages as its low input impedance is easier on Monica's TDA1545A current output stage."
The review of the Burson audio buffer on tnt-audio http://www.tnt-audio.com/accessories/hdams_e.html says the minimum impedance that Monica2 should see is no less than 20K ohm.
On diyparadise, Yeo also suggests using a 50K ohm volume pot between Monica2 and Charlize.
My question: Is 20 / 50 K ohm very high compared to the GG gain stage?
One more question, Yeo also suggests "in order to avoid such signal loss, it's best to have at least a Z ratio of 1/50".
If I had a 50 K ohm volume between Monica2 and Charlize, does this mean the impedance ratio is 5 to 1 with the volume pot output to Charlize input, assuming Charlize "wants" and input impedance of 10 K ohm or less?
Thanks in advance, I hope these statements are sensible enough to warrant replies...
Andrew.
What exactly is the output impedance of Monica2 and the input impedance of Charlize?
The diyparadise article about the grounded grid tube gain stage, this statement indicate Monica2 should see a "lower" input impedance:
"Now GG works better than common cathode gain stages as its low input impedance is easier on Monica's TDA1545A current output stage."
The review of the Burson audio buffer on tnt-audio http://www.tnt-audio.com/accessories/hdams_e.html says the minimum impedance that Monica2 should see is no less than 20K ohm.
On diyparadise, Yeo also suggests using a 50K ohm volume pot between Monica2 and Charlize.
My question: Is 20 / 50 K ohm very high compared to the GG gain stage?
One more question, Yeo also suggests "in order to avoid such signal loss, it's best to have at least a Z ratio of 1/50".
If I had a 50 K ohm volume between Monica2 and Charlize, does this mean the impedance ratio is 5 to 1 with the volume pot output to Charlize input, assuming Charlize "wants" and input impedance of 10 K ohm or less?
Thanks in advance, I hope these statements are sensible enough to warrant replies...
Andrew.
Andrew, I am no electronics expert but over the years I have seen recommendations for imedance matching items in a hi-fi system, and they vary quite quite a lot. Only yesterday, I read an article (that you can download from the Jaycar web site) that says apart from microphones and amp/speakers, impedance matching is not important!
Early on, one of my 'gurus' told me that I should aim for a minimum of 1/10 (output impedance of preceding stage to input impedance of following stage). I've have also read a 1/100 ratio is ideal (and from other sources, ratios in between)!
It's safe to say that you want a higher input impedance on a following stage, and I have 'witnessed' that by going from a 10K attenuator after a NOS DAC to a 25K type. The improvement is obvious and as you have stated, Yeo suggests 50K.
This weekend I tried a 20K and 50K shunted pot between Burson buffer and Audiodigit CT MC4x100 and I prefer the 50K!
I may have got the 'wrong end of the stick' with regards to the input impedance of the 'digital' amps like Charlize, and they don't need such a low impedance volume control before them as I had thought.
So what's a boy to do?
Well how about this suggestion as we are on a DIY forum after all! Jaycar sell those small 9mm pots for not very much money. Unfortunately they only do 10K and 50K impedances but you can find the same pot elsewhere (Farnell) in 20K. Buy all three and try them. I am fairly sure that your ears will be able to tell you which is the right one in your system and if not then why worry?
Finally, an active stage between Monica2 and Charlize is not only there for impedance matching reasons. IMHO, a valve stage prior to an amp like Charlize makes for a very enjoyable sound!
Early on, one of my 'gurus' told me that I should aim for a minimum of 1/10 (output impedance of preceding stage to input impedance of following stage). I've have also read a 1/100 ratio is ideal (and from other sources, ratios in between)!
It's safe to say that you want a higher input impedance on a following stage, and I have 'witnessed' that by going from a 10K attenuator after a NOS DAC to a 25K type. The improvement is obvious and as you have stated, Yeo suggests 50K.
This weekend I tried a 20K and 50K shunted pot between Burson buffer and Audiodigit CT MC4x100 and I prefer the 50K!
I may have got the 'wrong end of the stick' with regards to the input impedance of the 'digital' amps like Charlize, and they don't need such a low impedance volume control before them as I had thought.
So what's a boy to do?
Well how about this suggestion as we are on a DIY forum after all! Jaycar sell those small 9mm pots for not very much money. Unfortunately they only do 10K and 50K impedances but you can find the same pot elsewhere (Farnell) in 20K. Buy all three and try them. I am fairly sure that your ears will be able to tell you which is the right one in your system and if not then why worry?Finally, an active stage between Monica2 and Charlize is not only there for impedance matching reasons. IMHO, a valve stage prior to an amp like Charlize makes for a very enjoyable sound!
Thanks for the reply, and thanks for pointing out those Alpha pots! I've just purchased a few from Jaycar, and at almost 1/10th the price of an Alps pot in New Zealand I'm sure I'll be able to live with them for a while.
I'd still like to find out the impedances of Monica2 and Charlize out of interest. Anyone?
I'd still like to find out the impedances of Monica2 and Charlize out of interest. Anyone?
Well I've had my Charlize amp running for about ~8 hours so far. I'm using a pair of 96db Adire HE10.1 speakers I've had for quite awhile. I'm using a tube (homebrew) preamplifier and a battery supply for the Charlize.
At first the sound was very strange sounding - voices sounded muffled and there wasn't a lot of detail compared to my heavily modified Dynaco 70. Then I realized the battery I was using was only reading 8 volts and needed a recharge.
I switched to another SLA battery I had on hand and the sound improved. Since I'm running a tube preamp that is already capacitor coupled, I then removed the stock Cerafine 'lytics. I also bypassed the incoming power supply with a small film cap. Listening again, the sounded definitely has improved even more. Lots of detail and it seems to do some things I have never heard with tubes or solid-state. It still sounds a little light-weight, polite, and undynamic with a quite forward sound.
Should I invest in a decent SMPS power supply or will the sound break-in even more as time goes on? Anyone recommend a good U.S. source for power supplies or will any old switching PS do?
At first the sound was very strange sounding - voices sounded muffled and there wasn't a lot of detail compared to my heavily modified Dynaco 70. Then I realized the battery I was using was only reading 8 volts and needed a recharge.
I switched to another SLA battery I had on hand and the sound improved. Since I'm running a tube preamp that is already capacitor coupled, I then removed the stock Cerafine 'lytics. I also bypassed the incoming power supply with a small film cap. Listening again, the sounded definitely has improved even more. Lots of detail and it seems to do some things I have never heard with tubes or solid-state. It still sounds a little light-weight, polite, and undynamic with a quite forward sound.
Should I invest in a decent SMPS power supply or will the sound break-in even more as time goes on? Anyone recommend a good U.S. source for power supplies or will any old switching PS do?
Hi everyone!
I'm just about to get my Autocostruire TA2020 back into action again after unfortunately frying the existing chip - classic mistake of wanting to hear your creation too quickly without checking everything first. I'd mistaken one of the diodes screen-printed + signs for being the DC in + sign! Turns out it was - DC in instead. The chip wasn't happy....!!!
Ready to go again now with a pair of the copper-tube Obbligato 2.2uF input caps, and x2 Panasonic FC 2200uF caps on the main board. Wiring for all is solid core copper.
I'm using the Skynet 8080 from NuuK. I remember using this with my modded Sonic T-amp and not liking the result too much compared with a cheap Maplin 13.8v regulated CB PSU, but this was using a 10,000k cap after the SMPS. I will try the Autocostruite TA2020 with the cap and without, but rather suspect I will prefer the sound without. The 10,000uf cap is an Elna Cerafine. Will be interested to hear how it sounds against my current reference amp, Greg Ball's GB150D.
Just one thing, what value bleed resistor should I fit to the Elna? It's 10,000uF and 63v.
Cheers,
- John
I'm just about to get my Autocostruire TA2020 back into action again after unfortunately frying the existing chip - classic mistake of wanting to hear your creation too quickly without checking everything first. I'd mistaken one of the diodes screen-printed + signs for being the DC in + sign! Turns out it was - DC in instead. The chip wasn't happy....!!!
Ready to go again now with a pair of the copper-tube Obbligato 2.2uF input caps, and x2 Panasonic FC 2200uF caps on the main board. Wiring for all is solid core copper.
I'm using the Skynet 8080 from NuuK. I remember using this with my modded Sonic T-amp and not liking the result too much compared with a cheap Maplin 13.8v regulated CB PSU, but this was using a 10,000k cap after the SMPS. I will try the Autocostruite TA2020 with the cap and without, but rather suspect I will prefer the sound without. The 10,000uf cap is an Elna Cerafine. Will be interested to hear how it sounds against my current reference amp, Greg Ball's GB150D.
Just one thing, what value bleed resistor should I fit to the Elna? It's 10,000uF and 63v.
Cheers,
- John
CHARLIZE VS MY 300B
Greetings Ladies and Gentlemen, I thought I would post my first experiences with you know who.Firstly a funny story, I bought charlize and monica together about 6 months ago and built mon first but promptlly fried it by putting the wrong power souce into it(dreaded AC).This put a damper on things and I lost my nerve and a few months went by before afriend offered to build charlize for me. Anyway he's been snowed under and hasn't bee able to touch it. Another friend who has lost his sight called me and asked me to build his charlize for him.Talk aboout the diy blind leading the blind but I supprised myself and got it going.Its on one of Yeos smps and it has a 100k pot with a rotel cd player going straight in outputting to Visaton b200 obs with sub below 150hz.
FIRST IMPRESSIONS
1. The detail is incredible, chip dry and laid bare.I found the vocals recessed and the lower mids and bass lackinng( iI know people say this improves with breakin so I'm not concerned).I didnt find the tops sibilant but it certainly seemed not so much top heavy as mid and bass light if you get what I mean.
2. the width of the sound stage went nuts extending much further left and right but I found ther was a whole in the middle and the soundstage had no depth to it at all. This I found disturbing as I think that my 300b has a good width but it has incredible depth to it,well behind the speakers which i find very pleasing. Also the 300b vocal range is pure honey with a pleasant slightly forward character.
3. the charlize and my 300b are similar power ratings but the charlize appears to have far less grunt than my 300b, infact a bit p weak but maybe this is due to my 300b only needing 300mv to reach full power.
I'm cretainly not throwing the baby out with the bath water but am curious about my findings and would appreciate any comments, advice ect
speak soon peace and goodwill fergs
Greetings Ladies and Gentlemen, I thought I would post my first experiences with you know who.Firstly a funny story, I bought charlize and monica together about 6 months ago and built mon first but promptlly fried it by putting the wrong power souce into it(dreaded AC).This put a damper on things and I lost my nerve and a few months went by before afriend offered to build charlize for me. Anyway he's been snowed under and hasn't bee able to touch it. Another friend who has lost his sight called me and asked me to build his charlize for him.Talk aboout the diy blind leading the blind but I supprised myself and got it going.Its on one of Yeos smps and it has a 100k pot with a rotel cd player going straight in outputting to Visaton b200 obs with sub below 150hz.
FIRST IMPRESSIONS
1. The detail is incredible, chip dry and laid bare.I found the vocals recessed and the lower mids and bass lackinng( iI know people say this improves with breakin so I'm not concerned).I didnt find the tops sibilant but it certainly seemed not so much top heavy as mid and bass light if you get what I mean.
2. the width of the sound stage went nuts extending much further left and right but I found ther was a whole in the middle and the soundstage had no depth to it at all. This I found disturbing as I think that my 300b has a good width but it has incredible depth to it,well behind the speakers which i find very pleasing. Also the 300b vocal range is pure honey with a pleasant slightly forward character.
3. the charlize and my 300b are similar power ratings but the charlize appears to have far less grunt than my 300b, infact a bit p weak but maybe this is due to my 300b only needing 300mv to reach full power.
I'm cretainly not throwing the baby out with the bath water but am curious about my findings and would appreciate any comments, advice ect
speak soon peace and goodwill fergs
Hi fergs,
Please try a lower valued pot, say 10K. The maximum impedance that this 10K pot will present at the inputs of Charlize will be 2.5 kOhms, much more suited to Charlize's input impedance of 20K. A 1:10 ratio between the impedances of the source and amplifier is a rule of thumb. You should get better results with the 10K pot.
Regards,
Ashok
Please try a lower valued pot, say 10K. The maximum impedance that this 10K pot will present at the inputs of Charlize will be 2.5 kOhms, much more suited to Charlize's input impedance of 20K. A 1:10 ratio between the impedances of the source and amplifier is a rule of thumb. You should get better results with the 10K pot.
Regards,
Ashok
