Looks like they quote some total effective (active) mass including some 6g cartridge. So 16g. 9.5Hz for the Dyna.
Hi,
Thanks, I'll survive.
We'll see where it will lead us but many thanks for all your input, you've been a great help.
Hopefully some other people will benefit from all this as well so at least we'll have that.
@Stajo: If your Dynavector cartridge is anything like their Karat then it really like a heavy tonearm. Best suited IMHO are the one from Dynavector themselves.
BTW, have you tried the 6SL7/6n9P yet in the last stage of the Itch?
Ciao,
Thanks, I'll survive.
We'll see where it will lead us but many thanks for all your input, you've been a great help.
Hopefully some other people will benefit from all this as well so at least we'll have that.
@Stajo: If your Dynavector cartridge is anything like their Karat then it really like a heavy tonearm. Best suited IMHO are the one from Dynavector themselves.
BTW, have you tried the 6SL7/6n9P yet in the last stage of the Itch?
Ciao,
@Stajo: If your Dynavector cartridge is anything like their Karat then it really like a heavy tonearm. Best suited IMHO are the one from Dynavector themselves.
BTW, have you tried the 6SL7/6n9P yet in the last stage of the Itch?
Ciao,
Hi, ok good to know. Dyna showed up today
I have never built the Itch, but I'm gathering the stuff from varius corners of my apartment as we speak. 6SL7 would give alot of amplification. I havent done the math yet but I think I came to something under half a volt at 45 dB from 2.5 mV and either I get that up with another stage, like an amplifying pre or I try another tubbie. 6SL7 is very high and I do have alot of them but, I had like 40-50:ish mu in mind. It might need a cathode follower also if meeting cabling after. Just based on a guess tho
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Hi,
Exactly, the gain of the first stage is reduced by the RIAA network (some 20dB) so if you stick a higher gain stage behind that the gain scaling is upset.
IOW, the first stage should have the higher gain then you gradually step down.
If I read Stajo correctly he'd like a phono pre with MM sensitivity and overload margins . IOW, a class MM phono with volctrl and buffer or low Zout, correct?
Ciao,
Exactly, the gain of the first stage is reduced by the RIAA network (some 20dB) so if you stick a higher gain stage behind that the gain scaling is upset.
IOW, the first stage should have the higher gain then you gradually step down.
If I read Stajo correctly he'd like a phono pre with MM sensitivity and overload margins . IOW, a class MM phono with volctrl and buffer or low Zout, correct?
Ciao,
Hi,
Exactly, the gain of the first stage is reduced by the RIAA network (some 20dB) so if you stick a higher gain stage behind that the gain scaling is upset.
IOW, the first stage should have the higher gain then you gradually step down.
If I read Stajo correctly he'd like a phono pre with MM sensitivity and overload margins . IOW, a class MM phono with volctrl and buffer or low Zout, correct?
Ciao,
Either "line level" out from RIAA or combined with amplifying pre is what goes around in my poor head atm yes, correct
How much signal does the first 6N2PEV like to have?
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All you have to do is buy a Current Limiting Diode at the desired value. There's no need to sort through a pile of JFETs.
Hi,
Exactly, the gain of the first stage is reduced by the RIAA network (some 20dB) so if you stick a higher gain stage behind that the gain scaling is upset.
IOW, the first stage should have the higher gain then you gradually step down.
If I read Stajo correctly he'd like a phono pre with MM sensitivity and overload margins . IOW, a class MM phono with volctrl and buffer or low Zout, correct?
Ciao,
With passive RIAA equalization, best S/N is achieved by putting all of the gain before the EQ network. The nature of the network is to reduce HF noise, so it's best to take advantage of that. I've seen this time and again in my spice simulations. Of course, this does not take into account power supply noise or 1/f noise.
The challenge of doing it this way is to provide a high gain stage with low distortion and good overload margin.
Hi,
Do you mind giving some examples because I've through a lot of these CLDs and still have no clue which one to pick. The can't be SMD and most of the ones I saw were LED drivers, is that correct?
Idss of the BF245A is 2.3mA to 6mA, max input voltage 30VDC.
Cheers,
Do you mind giving some examples because I've through a lot of these CLDs and still have no clue which one to pick. The can't be SMD and most of the ones I saw were LED drivers, is that correct?
Idss of the BF245A is 2.3mA to 6mA, max input voltage 30VDC.
Cheers,
Hi,
Do you mind giving some examples because I've through a lot of these CLDs and still have no clue which one to pick. The can't be SMD and most of the ones I saw were LED drivers, is that correct?
Idss of the BF245A is 2.3mA to 6mA, max input voltage 30VDC.
Cheers,
They are also called "Current Regulating Diodes".
I have attached the data sheets from Semitec and Central Semiconductor for your viewing pleasure.
As far as I know, these have nothing to do with LED's. They make both SMD and through hole versions of each CRD/CLD.
Please note the maximum voltage allowed across the device. The lower current values are typically good for 100 VDC, the higher ones only 30. They are also typically good (meaning: they will regulate the current) down to about 3 volts across the device.
Hi,
O.K. Thanks.
I found both sheets already but if we take for example 2 equal current diodes
in // will that actually double the current regulation or doesn't it work that way?
Say, 2//1N5309 of 3mA nominal each would then regulate a total of 6mA through the load.
Or, am I better off with a single CRD of say 5060mA typical?
Sorry for the stupid questions,
O.K. Thanks.
I found both sheets already but if we take for example 2 equal current diodes
in // will that actually double the current regulation or doesn't it work that way?
Say, 2//1N5309 of 3mA nominal each would then regulate a total of 6mA through the load.
Or, am I better off with a single CRD of say 5060mA typical?
Sorry for the stupid questions,
Of course you can parallel as many as you like to increase the current regulation amount, but it would be better to just use one. The reason is that unless they are matched for current regulation, then weird things might happen (I think).
They are basically a JFET and a resistor wired as a CCS and calibrated to a specific current. We use one in our solid state phono preamp, for example.
Hi,
I figured as much. The J-fet I used needs to be matched just the same, just like the tubes.
Anyway, thanks.
Ciao,
If you are talking about that circuit you described earlier with the 4 6DJ8's all in a row, then no, you don't have to go through that trouble.
You can simply use a 1mA CLD for each triode, but do NOT connect all of the plates together like you had it. Treat each triode as an individual, and use capacitors to connect them all to the same output. That way, you don't need to match tubes or CLD's, and none of the tubes will affect the others as they age and change characteristics.