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Valve info

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55 minutes ago, paulkebab said:

Yes indeed, I found a comparison table somewhere and it was obviously a non-starter if only for that but there was another major difference, poss the grid volts which you mentioned.

The 6N1P has the higher filament current, so it would not be a problem putting in a tube with a lower draw. The issue is the other specs. Depending on the circuit, max anode volts for 6N1P is higher. Again depending on the circuit, the maximum allowable cathode to heater voltage difference is greater as well. The grid is less of a problem, but it means that even if everything else works OK in terms of specs, you'd really want to change some resistor values to get a higher -V at the grid.

There's a lot involved in designing a circuit to get a valve operating at its best potential and whilst direct substitutes are fine, there are more than enough alternatives and generally it's a bad idea to use a tube with a different spec. Some designs have loads of headroom, others don't Especially they don't if the circuit has been designed to run them quite 'hard'.

Even close matches can be an issue. Most people/websites wil state that 6922, ECC88 and 6DJ8 are direct replacements. They aren't. The pre I'm in the process of finishing uses a circuit designed for a 6922. Normally, a 6DJ8 is indeed a direct replacement, but in this case, the design runs the 6922 quite close to some limits and the 6DJ8 cathode to heater maximum voltage is just lower enough compared with an ECC88 to cause an issue.

It's a minefield sometimes, and not helped by the fact that a great many datasheets either don't agree, or quote based on different operating parameters.

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Hi Tarzan,
No, I don't have direct experience of 6N1P because I have an impossibly long list of DIY circuits I want to build, few of which (in reality) I ever will. So my list of valves is long but any info I provide second hand about sonics is simply that - hearsay. If I have direct experience I make sure to refer to it
So saying in my valve regulated HV PSU the 6n1p is not an acceptable sub for the E188cc, it simply doesn't work. A pity as what I do need is bloody expensive and rare. Luckily I have a stash, so I'm safe unless I kill myself with the 1kV output...

Sent from my BLA-L09 using Tapatalk

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Posted (edited)
59 minutes ago, Jazid said:

Hi Tarzan,
No, I don't have direct experience of 6N1P because I have an impossibly long list of DIY circuits I want to build, few of which (in reality) I ever will. So my list of valves is long but any info I provide second hand about sonics is simply that - hearsay. If I have direct experience I make sure to refer to it emoji846.png
So saying in my valve regulated HV PSU the 6n1p is not an acceptable sub for the E188cc, it simply doesn't work. A pity as what I do need is bloody expensive emoji857.png and rare. Luckily I have a stash, so I'm safe unless I kill myself with the 1kV output...

Sent from my BLA-L09 using Tapatalk
 

That, young James, is always the way. I similarly have a reasonably large pile here. I need to finish a couple of bits first (not least because I don't actually have a good quality working pre at the moment). Plus the 'lost count of how many years' 300B PP I really, really need to finish. Basically because I've got nearly all the bits for it, in particular all the transformers and oddments.

After that, I really need to look at some of the odd valves I have from the 40s, 50s and 60s and see what I can do with a few. That lovely 13E1 OTL gave me a guilty pang. I've got enough transformers and rectifiers to sink a ship, and they're all just gathering dust. Not the same, but I found a pair of NOS 12E1s in the collection that I'd forgotten about, plus some other interesting bits (fancy a pair of half-wave mercury rectifiers good for about 1.75K?). Once the pre is out of the way (actually, two, but that's a long story), I'll try and put aside an evening or two a week.

Trouble is, I get distracted. I'll start looking at a potential idea, search in the pile to make sure I've got the basics, turn to Morgan Jones for some inspriation and calculation, then get sidetracked by one of his intersting designs and start wondering if I could adapt it to fit something I've got which has nothing to do with the idea I started out with. Next thing, it's 2 am and I haven't even soldered up the broken interconnect that's been driving me nuts for weeks. Not to mention the perils of the auction site whose name shall not be spoken. I simply cannot buy two small, unusual and therefore cheap tubes to use in a voltage regulator. Not when someone is listing a box of 50 assorted others as well. Thanks to that addiction, I have a stupid collection of all but worthless small pentodes. I'm sure I can try and work something out to do with them...

It's all a lot cheaper (and healthier) than some of my old habits mind, so I can't complain really.

Edited by rabski
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Just sharing a  tube doubt. Will using tube amps to run active speakers, with direct coupling to drivers, without any passive crossover,  be just as safe as using SS amps.

If under operation, a tube suddenly goes Kaput, will the amp pass dangerous voltages ( especially DC ) to the drivers. Thanks.

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Depends rather. If they are transformer or capacitor coupled then you are relatively safe, if they are eg. OTLs then yes, you're taking a risk.

Sent from my BLA-L09 using Tapatalk

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On 20/04/2019 at 16:12, newlash09 said:

Just sharing a  tube doubt. Will using tube amps to run active speakers, with direct coupling to drivers, without any passive crossover,  be just as safe as using SS amps.

If under operation, a tube suddenly goes Kaput, will the amp pass dangerous voltages ( especially DC ) to the drivers. Thanks.

I did just that with EL84s to the HF and 845s to the MF drivers.  Even though an 845 went cranky the speakers were fine.  YMMV, of course.

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7 hours ago, awkwardbydesign said:

I did just that with EL84s to the HF and 845s to the MF drivers.  Even though an 845 went cranky the speakers were fine.  YMMV, of course.

Thanks a lot awkwardbydesign :)

That was just the reassurance I was looking for.. :)

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After more listening time and considering the improvement the Mullard ECC83 has made to the headamp, I have decided to pursue the 12AU7 replacement, Watford valves say the Mullard ECC82 is a straight swap. If anyone can confirm this or otherwise I would be v grateful, however I am waiting for a reply from Vincent as to why this valve is in the headamp in the first place. The SV237 amp sounds absolutely superb to me and my partner, so I'm not going to bother chasing a 6N1P alternative. 

Whilst I was chatting to the importer he pointed out the new Vincent DAC which has sort of slapped me in the face. Dammit...and on home demo too..double dammit. Every bloody time I talk to him he throws his fishing line out, he's a good salesman I'll give him that!

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17 hours ago, newlash09 said:

Thanks a lot awkwardbydesign :)

That was just the reassurance I was looking for.. :)

Bear in mind, that if you use a normal tweeter you will still need a large capacitor in series with it to block DC or any switch on pulses.  I was using a Jordan 2" driver that works down to around 100Hz, so I didn't need one.  

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2 hours ago, awkwardbydesign said:

Bear in mind, that if you use a normal tweeter you will still need a large capacitor in series with it to block DC or any switch on pulses.  I was using a Jordan 2" driver that works down to around 100Hz, so I didn't need one.  

Thanks again for the guidance awkwardbydesign :)

Iam not sure of the tweeter specs of the pmc 20.26. So I guess it might be safest to keep the present passive crossover in place, and not go completely active by removing it.

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3 hours ago, paulkebab said:

After more listening time and considering the improvement the Mullard ECC83 has made to the headamp, I have decided to pursue the 12AU7 replacement, Watford valves say the Mullard ECC82 is a straight swap. If anyone can confirm this or otherwise I would be v grateful, however I am waiting for a reply from Vincent as to why this valve is in the headamp in the first place. The SV237 amp sounds absolutely superb to me and my partner, so I'm not going to bother chasing a 6N1P alternative. 

Whilst I was chatting to the importer he pointed out the new Vincent DAC which has sort of slapped me in the face. Dammit...and on home demo too..double dammit. Every bloody time I talk to him he throws his fishing line out, he's a good salesman I'll give him that!

Paul, glad you are enjoying the Vinny-  replace the standard valves- they really hold the amp back...….

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Well I had a rethink and went for the ECC82/ 12AU7 in the headamp replacement and the 6N1P's in the integrated have been replaced by Harma's. 

The headamp especially sounds superb to me. The most listenable, cheap and easy upgrade I've ever done and heard. The headamp now has an ECC83 and ECC82 and sounds stunning, I cant decide which sound better, the Oppo PM1 or the Shure 1540 but once I've EQ'd them out they both sound amazing. The Harma 6N1P's sound a lot clearer, not as much of a difference as the ECC83 made but definitely there. The output seems a little lower than the original tubes but that's no big deal.

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Put an NOS valve in the window position Paul.;-)

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12 hours ago, Tarzan said:

Put an NOS valve in the window position Paul.;-)

No choice really 9_9

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On 13/08/2018 at 18:53, Clint said:

Good evening all! I've found this rather interesting site... Does anyone know about this? 

https://brimaruk.com/menugbvp/great-british-valve-project-2/

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