Hi All,
So my phono is getting better an better. I like it by replacing my stock one but sometimes especially daytime i would like more volume. I have a B1 buffer and after that a Zen variant (something like this
http://www.passdiy.com/pdf/retofzen.pdf
with 3.3uF in and out cap and some further mod ). Form B1 out i eliminated the 10uF cap.
I'm thiking of buying or building a preamp with gain. So the question is build or buy.
An old Parasound php750 would be enough or should i consider an aleph p or ... ?
With or w/o my B1 the sound seems to be similar for me. Maybe better w/o B1 but i need some attenuator.
On the other hand i know a ladder attenuator is a great alternative to adjust volume.
Any advice or example of your system would be appreciated.
Karesz
So my phono is getting better an better. I like it by replacing my stock one but sometimes especially daytime i would like more volume. I have a B1 buffer and after that a Zen variant (something like this
http://www.passdiy.com/pdf/retofzen.pdf
with 3.3uF in and out cap and some further mod ). Form B1 out i eliminated the 10uF cap.
I'm thiking of buying or building a preamp with gain. So the question is build or buy.
An old Parasound php750 would be enough or should i consider an aleph p or ... ?
With or w/o my B1 the sound seems to be similar for me. Maybe better w/o B1 but i need some attenuator.
On the other hand i know a ladder attenuator is a great alternative to adjust volume.
Any advice or example of your system would be appreciated.
Karesz
If 2x gain is what needed, make Juma's BF862 pre. If you find it difficult or 6dB not enough, then BOZ is simple, 15dB, and good standard. My system has a sensitive valve amp, so no need. Buffer on a Zen is low gain chain.
Second stage would increase enough THD. I would buffer it and use an op amp if I wanted higher gain low THD drive directly to an amp. Although en for second stage would worsen a little due to op amp's Rin and feedback resistors. Example. With 0.6mV Eroica would give +7dB from his now phono for 850mVRMS low THD and buffered output to Zen, plus line level extra unity gain inputs with a switch. Don't know if x2.2 will be enough in his system or not, still. The LPs have higher velocities than 5cm used in nominal cart spec, but there are many quiet pressings too.
Nice Board Merlin
Hi Felipe
Nice looking board.
How's the tuning going ?
Looks like you've got some fancy resistors in there.
I am wondering whether to splash some cash and do the same.
What are the 4 big space capsules that have landed in the middle ?
Thanks for the Thorens stuff again, haven't got the measurement yet.
Have also started looking at my Dual with a veiw to re-plinth and arm it.
I am afraid I might have got the diy tonearm bug from looking at the site too much !
Cheers Simon...
Hi Felipe
Nice looking board.
How's the tuning going ?
Looks like you've got some fancy resistors in there.
I am wondering whether to splash some cash and do the same.
What are the 4 big space capsules that have landed in the middle ?
Thanks for the Thorens stuff again, haven't got the measurement yet.
Have also started looking at my Dual with a veiw to re-plinth and arm it.
I am afraid I might have got the diy tonearm bug from looking at the site too much !
Cheers Simon...
Hi everyone,
I haven't had a chance to swap the zener for a resistor yet Salas, so I can't comment on that mod yet.
I was wanting to know what the input sensitivity of the Simplistic pre is (in MM form)... more specifically, is it possible that I could clip it with a high output cart (5mV @ 5cm/1kHz) while playing a hot record?
Last night, while recording some records for comparison after tweaking the pre, I was pegging the meters on the audio interface when set to receive -10dBu. Salas Pre was going straight into the Apogee Ensemble. When on pro-level (+4dBu) all was good of course. I noticed some distorted sounds on a record that I hadn't played for some time... though this could be the material and I just haven't heard it so clearly before.
Thanks,
Tani.
I haven't had a chance to swap the zener for a resistor yet Salas, so I can't comment on that mod yet.
I was wanting to know what the input sensitivity of the Simplistic pre is (in MM form)... more specifically, is it possible that I could clip it with a high output cart (5mV @ 5cm/1kHz) while playing a hot record?
Last night, while recording some records for comparison after tweaking the pre, I was pegging the meters on the audio interface when set to receive -10dBu. Salas Pre was going straight into the Apogee Ensemble. When on pro-level (+4dBu) all was good of course. I noticed some distorted sounds on a record that I hadn't played for some time... though this could be the material and I just haven't heard it so clearly before.
Thanks,
Tani.
Yours is the 41dB MM from the pdf yes? That should be 560mV RMS for MM 5mV. -10dbu=245mV RMS. Records can have +12dB modulations here and there. If its OK on +4dbu then its not self clipping. Check with an AC meter and a steady tone what mV you see. Maybe you got stronger Fets and more than 41dB gain even.
Yes, 41dB MM gain from the pdf. I only have a DMM of 'reasonable' quality, which I believe can only measure AC with any accuracy up to 400Hz or so. I can't use this frequency to check gain directly as it will be boosted by the RIAA, right? Can I simply check output mV at such a low frequency and have it be representative of the overall output?
I think I need a scope and some test records if I'm gonna take this mixer project seriously?
I think I need a scope and some test records if I'm gonna take this mixer project seriously?
Found These R-Cores After Searching For 3 Days.
Found R-core after very long search.
Seems to be very hard to get item.
I would like to make pre all in one 19" x 340 case.
Looks like I might get away with it with R-core.
This one is only 30va but not to high to fit in 1u case.
I could use 2 to bump it up to 60va.
Cheers Peoples...Simon...
Found R-core after very long search.
Seems to be very hard to get item.
I would like to make pre all in one 19" x 340 case.
Looks like I might get away with it with R-core.
This one is only 30va but not to high to fit in 1u case.
I could use 2 to bump it up to 60va.
Cheers Peoples...Simon...
Attachments
Hi Salas,
just to let you know, everything´s on its way.
All BC´s and 170´s well matched, for PSU i have Dale and MOX resistors at hand,
takmans for the RIAA circuit are ordered and on their way.
Lytics are Panasonic FM, RIAA-Caps are Polystyrene plus mica-finetuning.
Will go for EI-Core plus Rectification in an external Housing and double PSU and
Circuit in main box.
Until res. arrive, ´m thinking about grounding and positioning parts on tagboard.
What do you think?
Thanks and pictures will follow at the time...
Thanks and Greetings Ulf
just to let you know, everything´s on its way.
All BC´s and 170´s well matched, for PSU i have Dale and MOX resistors at hand,
takmans for the RIAA circuit are ordered and on their way.
Lytics are Panasonic FM, RIAA-Caps are Polystyrene plus mica-finetuning.
Will go for EI-Core plus Rectification in an external Housing and double PSU and
Circuit in main box.
Until res. arrive, ´m thinking about grounding and positioning parts on tagboard.
What do you think?
Thanks and pictures will follow at the time...
Thanks and Greetings Ulf
Last edited:
Hi Salas,
yes components testing is quite awful ;-) we´ll see.
Just two more questions....
what´s the current, the CCS draws? Because i´ll take
36VAc Transformer and want to calculate the voltage-
dropresistor after rectification.
Second: What resistance do you recommend for testing
the PSU if ´ll take double (stereo) PSU?
Okay, allow one more question...whats your favorite
cap-combo?
Greetings Ulf
yes components testing is quite awful ;-) we´ll see.
Just two more questions....
what´s the current, the CCS draws? Because i´ll take
36VAc Transformer and want to calculate the voltage-
dropresistor after rectification.
Second: What resistance do you recommend for testing
the PSU if ´ll take double (stereo) PSU?
Okay, allow one more question...whats your favorite
cap-combo?
Greetings Ulf
Hi Felipe
Nice looking board.
How's the tuning going ?
Looks like you've got some fancy resistors in there.
I am wondering whether to splash some cash and do the same.
What are the 4 big space capsules that have landed in the middle ?
Thanks for the Thorens stuff again, haven't got the measurement yet.
Have also started looking at my Dual with a veiw to re-plinth and arm it.
I am afraid I might have got the diy tonearm bug from looking at the site too much !
Cheers Simon...
Hi Simon,
Thank you, the photo is my new balanced phono NJFET RIAA (four channels instead two channels) I'm waiting the teflon film & foil RIAA caps 15nF to do the final RIAA tuning.
Resistors are PRP metal film (red) Takman carbon film (pink) Kiwame (green) & Koa Speer & Xicon both carbon film (brown) I don't remember the name but are metal film (blue).
The trimmers are Bourns (4 small capsules blues near the gnd star screw)
About intestage cap: no doubt russian FT3 0.1uF 600V +-5 tolerance are my 1st choice (are the 4 big space capsules), for RIAA best teflon film & foil or minimum silver mica, for output cap a very good combo with interstage russian teflons are Mundorf Paper In Oil Silver Gold Oil. The photo is showing russian teflons FT3 insterstage & Auricaps output.
Lytics are Nichicon Muse (black) & Elna Silmic II (brown).
It's very important to do a good TT setup: Arm alignement, VTF, VTA, etc.
Cheers, Felipe
Balanced NJFET Phono
Hi Felipe
I guess DJ's would think your board rocks for 2x Technics (coolest club pre ever !!!).
But seriously Felipe, what are you connecting to, linestage? amp?
You must be using some kind of step-up balanced transformer?
Am interested in the way you will use it.
Cheers Simon...
Hi Felipe
I guess DJ's would think your board rocks for 2x Technics (coolest club pre ever !!!).
But seriously Felipe, what are you connecting to, linestage? amp?
You must be using some kind of step-up balanced transformer?
Am interested in the way you will use it.
Cheers Simon...
180-200mA with R1=10R 2W in the reg.
1K 5W test resistors.
Teflon interstage, PIO teflon bypassed out.
Hi Salas
Have now read all the 'valve itch' thread and today went right back to the start of this one to understand it's begining properly.
All very interesting stuff.
I originaly joined the site to be involved in a power amp build, and thought Nelson's BA-1 was what I would go for (the BA-1 thread seems to be as dead as a door-nail).
Since then I have been diverted away from this single aim to consider a much wider improvement to my whole system, and to try and come up with a whole integrated plan (even if this takes some time to implement, I quite like working on parallel projects as I think things move faster for me this way).
Verdict is still out on 'itch' vers 'JFET', but it's about 75% in favour of the JFET (I would love to do them both of course).
The question I wanted to ask you since your obviously a bit of a tube-head is, have you ever listened to a Mullard 5-10 amp and what do you think ?
The reason I'm interested is that it may resolve my phono decision.
Basicaly I've had a pair of Heathkit MA-12's for ages and never realised until now they were based on the 'classic' Mullard design.
I have never heard them at their best as they obviously need rebuilding, but if they were, would put some glass in my system even if I didn't build the 'itch'.
If you have any comments on the Mullard 5-10 / Heathkit MA-12, I would be interested to hear them.
Cheers Simon...
Have now read all the 'valve itch' thread and today went right back to the start of this one to understand it's begining properly.
All very interesting stuff.
I originaly joined the site to be involved in a power amp build, and thought Nelson's BA-1 was what I would go for (the BA-1 thread seems to be as dead as a door-nail).
Since then I have been diverted away from this single aim to consider a much wider improvement to my whole system, and to try and come up with a whole integrated plan (even if this takes some time to implement, I quite like working on parallel projects as I think things move faster for me this way).
Verdict is still out on 'itch' vers 'JFET', but it's about 75% in favour of the JFET (I would love to do them both of course).
The question I wanted to ask you since your obviously a bit of a tube-head is, have you ever listened to a Mullard 5-10 amp and what do you think ?
The reason I'm interested is that it may resolve my phono decision.
Basicaly I've had a pair of Heathkit MA-12's for ages and never realised until now they were based on the 'classic' Mullard design.
I have never heard them at their best as they obviously need rebuilding, but if they were, would put some glass in my system even if I didn't build the 'itch'.
If you have any comments on the Mullard 5-10 / Heathkit MA-12, I would be interested to hear them.
Cheers Simon...
Simon,
IMHO, I think you would be suprised at the performance and sound of the Jfets. They are the only "SS" amplification I have in my system. I considered tubes as well but am VERY happy that I choose this path. One day I may consider building a tube head amp but not for a while.
The Mullard 5-20 is a good sound amp. Not familiar with the 5-10's characteristics.
IMHO, I think you would be suprised at the performance and sound of the Jfets. They are the only "SS" amplification I have in my system. I considered tubes as well but am VERY happy that I choose this path. One day I may consider building a tube head amp but not for a while.
The Mullard 5-20 is a good sound amp. Not familiar with the 5-10's characteristics.
Hi Salas
Have now read all the 'valve itch' thread and today went right back to the start of this one to understand it's begining properly.
All very interesting stuff.
I originaly joined the site to be involved in a power amp build, and thought Nelson's BA-1 was what I would go for (the BA-1 thread seems to be as dead as a door-nail).
Since then I have been diverted away from this single aim to consider a much wider improvement to my whole system, and to try and come up with a whole integrated plan (even if this takes some time to implement, I quite like working on parallel projects as I think things move faster for me this way).
Verdict is still out on 'itch' vers 'JFET', but it's about 75% in favour of the JFET (I would love to do them both of course).
The question I wanted to ask you since your obviously a bit of a tube-head is, have you ever listened to a Mullard 5-10 amp and what do you think ?
The reason I'm interested is that it may resolve my phono decision.
Basicaly I've had a pair of Heathkit MA-12's for ages and never realised until now they were based on the 'classic' Mullard design.
I have never heard them at their best as they obviously need rebuilding, but if they were, would put some glass in my system even if I didn't build the 'itch'.
If you have any comments on the Mullard 5-10 / Heathkit MA-12, I would be interested to hear them.
Cheers Simon...
I haven't seen any Mullard original in the flesh or any Heathkit for that matter, but my amp I designed it around the classic Mullard topology and I like it enough for its output class. You can see the CCT and the ampo guy himself in the attachments, has some local design differences than a heritage amp of course, it also got some cap bypassed Leds instead of its main cathode resistor in its first stage lately. Scott knows about it, we have discussed about his next of kin topologically but more robust Opus amp in his power amp making thread.
Attachments
Hi Felipe
I guess DJ's would think your board rocks for 2x Technics (coolest club pre ever !!!).
But seriously Felipe, what are you connecting to, linestage? amp?
You must be using some kind of step-up balanced transformer?
Am interested in the way you will use it.
Cheers Simon...
I connected to 2 stereo line amps Erno Borbely so true balanced linestage & final two mono amps also Erno Borbely 75W RMS Class A also balanceds.
Linestage & poweramps Borbely no transformers or caps on the signal way
Cheers, Felipe