6158/13d3
I have some of these, and am in fact using one in the front of an amplifier I am just completing.
I have built test circuits for 13D3 and tested for distortion.
13D3 is a very good valve. At +28dB out (about 19v rms) THD is about 0.12%; and as with most triodes this drops with level. Higher order harmonics are extremely low. Please do not take this as statistically correct as I tested only four sections; to be 95% certain, one would have to test probably about 100.
I have seldom commented on the "sound" of valves, but I would expect this one to be very good.
7N7
I have some of these, and am in fact using one in the front of an amplifier I am just completing.
I have built test circuits for 13D3 and tested for distortion.
13D3 is a very good valve. At +28dB out (about 19v rms) THD is about 0.12%; and as with most triodes this drops with level. Higher order harmonics are extremely low. Please do not take this as statistically correct as I tested only four sections; to be 95% certain, one would have to test probably about 100.
I have seldom commented on the "sound" of valves, but I would expect this one to be very good.
7N7
THE ODD BRIMAR VALVES
Hi,
IMO if you need something in the range of a ECC82/12AU7A the 13D3 would be the better choice.
And I just love these black graphite coated plates,they have something the others don't...a bit of magic.🙂
Cheers,😉
Hi,
IMO if you need something in the range of a ECC82/12AU7A the 13D3 would be the better choice.
And I just love these black graphite coated plates,they have something the others don't...a bit of magic.🙂
Cheers,😉
BYPASS.
Hi,
So far I always found cathode bypass caps to be extremely critical for the sound of a preamp.
In fact so much so that I would rather do without them given a choice.
Which leaves us with the second circuit,this has too low gain as it is and a rather high Zo.
No big issue since you may need a line level preamp as well or do you have one already?
Just let me know,😉
Hi,
So far I always found cathode bypass caps to be extremely critical for the sound of a preamp.
In fact so much so that I would rather do without them given a choice.
Which leaves us with the second circuit,this has too low gain as it is and a rather high Zo.
No big issue since you may need a line level preamp as well or do you have one already?
Just let me know,😉
Re: THE ODD BRIMAR VALVES
Well, as I said on the INtroductions section, I am on best behaviour as I am new
, so I will keep my comments about 12AU7 to myself.
However, 13D3 is not an alternative to 12AU7: 13D3's mu is 32, whilst 12AU7s is about 18. In fact in my 13D3 test circuit , a mu-follower, I got gain of 30dB = 31.6.
I cannot believe how many people think that ECC32 is a "6SN7" It is not.
13D3 has a high anode resistance, so would make a poor driver (it should make an excellent voltage amplifier though).
The best alternative for 12AU7 is probably 6CG7 (supposedly a 9-pin 6SN7). Other 9-pin alternatives that would provide better drive were it required would include, 5687, 6350, 6463, 6900, 12BH7, 6H30P, ECC99.
In octal, obviously 6SN7, and for loads of beef, 6BL7.
In Loctal, 7N7, 7AF7.
In addition, the dissimilar TV double triodes are worth looking at: 6EA7, 6EM7, 6DN7, 6CY7, 6DE7, 6EW7.
7N7
fdegrove said:
Well, as I said on the INtroductions section, I am on best behaviour as I am new
, so I will keep my comments about 12AU7 to myself.However, 13D3 is not an alternative to 12AU7: 13D3's mu is 32, whilst 12AU7s is about 18. In fact in my 13D3 test circuit , a mu-follower, I got gain of 30dB = 31.6.
I cannot believe how many people think that ECC32 is a "6SN7" It is not.
13D3 has a high anode resistance, so would make a poor driver (it should make an excellent voltage amplifier though).
The best alternative for 12AU7 is probably 6CG7 (supposedly a 9-pin 6SN7). Other 9-pin alternatives that would provide better drive were it required would include, 5687, 6350, 6463, 6900, 12BH7, 6H30P, ECC99.
In octal, obviously 6SN7, and for loads of beef, 6BL7.
In Loctal, 7N7, 7AF7.
In addition, the dissimilar TV double triodes are worth looking at: 6EA7, 6EM7, 6DN7, 6CY7, 6DE7, 6EW7.
7N7
13D3
Hi,
I agree,I didn't mean to imply these were equivalent valves.
They are definetely NOT although they share the same 9A pinout.
Apparently the 13D3 was used by Western Electric in the fifties as an input valve (voltage amplifier) for a number of their PP amps.
We don't bite,do we?😀
Cheers,😉
Hi,
I agree,I didn't mean to imply these were equivalent valves.
They are definetely NOT although they share the same 9A pinout.
Apparently the 13D3 was used by Western Electric in the fifties as an input valve (voltage amplifier) for a number of their PP amps.
We don't bite,do we?😀
Cheers,😉
INTO ZEN.
Hi,
I just had a look at this preamp.
It should work fine with either one of your proposed circuits.
Cheers,😉
Hi,
I just had a look at this preamp.
It should work fine with either one of your proposed circuits.
Cheers,😉
thanks fdegrove and 7N7 too for that info on 6158. I'm finally smug with the knowledge that I have a couple of tubes, of which i know nothing about, but which is supposed to be really cool...a satisfied 🙂
fdegrove..sir..I am veering towards the 1st schematic following your previous comments. Do you give a green signal on that one..and besides those ..uggh.. black gates ...and changes??
thanks a lot to both of you
fdegrove..sir..I am veering towards the 1st schematic following your previous comments. Do you give a green signal on that one..and besides those ..uggh.. black gates ...and changes??
thanks a lot to both of you
GREEN LIGHT.
Hi,
Go for it I'd say.
As for C5,C6,since you can't get the BGs,use the best electrolytic caps you can find and bypass each with 1 mF + 0.100 mF + 0.010 mF good quality polypropylenes to improve HF response.
Keep I/C length at the bare minumum,the output impedance of the second stage is still on the high side.
As for the PSU,I'd choose the one with the tube rectifier and choke filter.
I can only hope the AC heaters won't give trouble on the phono stage and the small chokes are a nice idea,so I'd put these in as well.
Take care of grounding pin #9 of the ECC88/6DJ8 since this is a shield.
Happy building,😉
Hi,
Go for it I'd say.
As for C5,C6,since you can't get the BGs,use the best electrolytic caps you can find and bypass each with 1 mF + 0.100 mF + 0.010 mF good quality polypropylenes to improve HF response.
Keep I/C length at the bare minumum,the output impedance of the second stage is still on the high side.
As for the PSU,I'd choose the one with the tube rectifier and choke filter.
I can only hope the AC heaters won't give trouble on the phono stage and the small chokes are a nice idea,so I'd put these in as well.
Take care of grounding pin #9 of the ECC88/6DJ8 since this is a shield.
Happy building,😉
I'd advise chosing low impedance types. There are often advertised as being suitable for switch mode power supplies.
Cheers,
thanks fdegrove for the green light...oh dear..you literally live in this board😀
- for C4 and C5 I'll use Phillips El caps..better than avarage IMHO.
- Will use the choke PSU.
- Will use DC heating. Any particular worry on that
- You mean to ground the pin 9 to the chassis..no??
thanks for the help. really appreciate it and hope to raciprocate in some way soon.
cheers
- for C4 and C5 I'll use Phillips El caps..better than avarage IMHO.
- Will use the choke PSU.
- Will use DC heating. Any particular worry on that
- You mean to ground the pin 9 to the chassis..no??
thanks for the help. really appreciate it and hope to raciprocate in some way soon.
cheers
DC.
Hi,
In that case I would use a higher voltage xformer (~8 to 10 V), no need for a center tap,rectify these with a full wave bridge,filter with a cap of say 10 to 47.000 mF/35VDC then use a regulator such as a 7806 and another cap of similar value as the former behind it.
Ground the heaters at pin # 5 (you can connect pin # 9 here as well).
Yes,if that is what you're using as ground/earth.
Use star earthing technique for best results:
AIKEN
Check Techinfo,Technical papers,Advanced > "Star grounding".
All the other articles are well worth reading as well.
Ciao,😉
Hi,
In that case I would use a higher voltage xformer (~8 to 10 V), no need for a center tap,rectify these with a full wave bridge,filter with a cap of say 10 to 47.000 mF/35VDC then use a regulator such as a 7806 and another cap of similar value as the former behind it.
Ground the heaters at pin # 5 (you can connect pin # 9 here as well).
Yes,if that is what you're using as ground/earth.
Use star earthing technique for best results:
AIKEN
Check Techinfo,Technical papers,Advanced > "Star grounding".
All the other articles are well worth reading as well.
Ciao,😉
PSU.
Hi,
Just a thought...If you would use another 5 H choke + cap after L1 you could have some interchannel independence for the PSU.
One would feed the R channel, the other the L one.
It would improve IMD for a reasonable outlay.
Cheers,😉
Hi,
Just a thought...If you would use another 5 H choke + cap after L1 you could have some interchannel independence for the PSU.
One would feed the R channel, the other the L one.
It would improve IMD for a reasonable outlay.
Cheers,😉
Bel E88CC
To Corbato:
I have been looking for a pair of NOS Bel E88CC. I don't know when you posted your message, but I am very interested in obtaining a pair.
If you could get in touch with me, please.
Thank you,
Eli
To Corbato:
I have been looking for a pair of NOS Bel E88CC. I don't know when you posted your message, but I am very interested in obtaining a pair.
If you could get in touch with me, please.
Thank you,
Eli
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