Ailean
New member
No chance, I'm a Beginner (yes that capital B is deliberate). I just a tone junkie 
Me
Member
Must be a rich beginner then! 
Ailean
New member
Rich no, easily parted with my money, yes.
I've been 'playing' for about 2 years, but work means I don't get time to pratice, and even when I do, it will be a while before I can again, so 1 step forward 1 step backwards.
My wife has been playing the same time, but she has lessons and practices more, so she can actually play! And we are both tone junkies.
I've been 'playing' for about 2 years, but work means I don't get time to pratice, and even when I do, it will be a while before I can again, so 1 step forward 1 step backwards.
My wife has been playing the same time, but she has lessons and practices more, so she can actually play! And we are both tone junkies.
Me
Member
Tell me about it. I practice and play a lot, get as good as I used to be, then after working too much and being too busy I'm back to sloppy loose playing again.
Did anyone have any input on what happens if I do use a 12AT7 for phase inverter?
Did anyone have any input on what happens if I do use a 12AT7 for phase inverter?
Ailean
New member
The manual says it should be a 12AT7, I'd use that.
http://diezel.typo3.inpublica.de/uploads/tx_ohelement/Herbertenglish_02.pdf
Page 17, chapter 4 (verse 2 )
http://diezel.typo3.inpublica.de/uploads/tx_ohelement/Herbertenglish_02.pdf
Page 17, chapter 4 (verse 2
)
SpicedMuffin
New member
I know the manual say's it but do not use a 12at7
your herbert uses alll 12ax7 in its preamp tubes as
I explained before Peter Diezel corrected me on this
as I thought the same thing as well so just make sure
you have a ballanced high grade 12ax7 in V1 and you will
be fine but if you put the 12at7 you could risk damage
to your amp
your herbert uses alll 12ax7 in its preamp tubes as
I explained before Peter Diezel corrected me on this
as I thought the same thing as well so just make sure
you have a ballanced high grade 12ax7 in V1 and you will
be fine but if you put the 12at7 you could risk damage
to your amp
Me
Member
Since it's lower gain I doubt it could damage it using 12AT7/ECC81! I'm not sure what difference it'd make sending less signal to the power section though, other than having too turn the volume knob up further for the same volume.
Peter? Duesentrieb? What's the difference, and why now the ECC83 instead of ECC81 as per the manual. Is it just easier to bulk buy ECC83s since they're in the rest of the amp, and either is fine, or is this through selective testing and the newest model Herberts are actually slightly different to when the manual was written?
BTW, the problem was my V4 or V5 tube. (I'm guessing V4, but I changed V5 at the same). I swapped for some old ones hanging about. Tonight it's getting a complete new set of preamp tubes.
I'm going to try to begin with (although these might all change around after experimenting!
V1: Cryogenically treated Philips JAN ECC83/5751
V2: Harma ECC83 Retro
V3, V4, & V5: Harma STR ECC83
V6: Harma Balanced ECC81
Power tubes: are all Harma STR EL34s which have always been solid for me in all my amps (except when plugged in a duff speaker cab!
)
Peter? Duesentrieb? What's the difference, and why now the ECC83 instead of ECC81 as per the manual. Is it just easier to bulk buy ECC83s since they're in the rest of the amp, and either is fine, or is this through selective testing and the newest model Herberts are actually slightly different to when the manual was written?
BTW, the problem was my V4 or V5 tube. (I'm guessing V4, but I changed V5 at the same). I swapped for some old ones hanging about. Tonight it's getting a complete new set of preamp tubes.
I'm going to try to begin with (although these might all change around after experimenting!
V1: Cryogenically treated Philips JAN ECC83/5751
V2: Harma ECC83 Retro
V3, V4, & V5: Harma STR ECC83
V6: Harma Balanced ECC81
Power tubes: are all Harma STR EL34s which have always been solid for me in all my amps (except when plugged in a duff speaker cab!
)
duesentrieb
Well-known member
No idea who has put 12AT7 into the manual - and which manual? From the UK site or the official?
Just use ECC83/12AX7 with selected for V1 and V2.
Of course an ECC81/12AT7 won't harm the amp. You just have 70% gain/amplification/output from that stage - and its always nice to experiment with lower gained tubes (ECC81, 12AT7, 5751) in certail positions like V1, V2 or the PI.
Just use ECC83/12AX7 with selected for V1 and V2.
Of course an ECC81/12AT7 won't harm the amp. You just have 70% gain/amplification/output from that stage - and its always nice to experiment with lower gained tubes (ECC81, 12AT7, 5751) in certail positions like V1, V2 or the PI.
Me
Member
Both say that! Both manuals are slightly different but section 4.2 of the UK/english one on the main Diezel site says...duesentrieb":11e2b4zn said:
"The pre-amps are equipped with 12AX7 tubes in all positions, except the phase inverter, which is a 12AT7."
duesentrieb
Well-known member
I will change that.
Me
Member
I just retubed the preamp all with good, brand new trustworthy valves I got delivered today. Sounded great. Played it for about 2.5hrs. Now it's gone silent again, just like before. Haven't bashed it, moved it, touched it. I was only playing it at "the neighbours are asleep" level. No send level to the FX processor again, as before.
Any clues? Can I measure/check anything? what voltages should I get on which preamp tube socket pins? what can I check inside? I'll try ANYTHING. I NEED this amp to work NOW! We're currently trying to write and record new songs and I've now already missed the deadline for the demo we were trying to send out. I've got a multimeter/oscilloscope/etc. Could it have done something to have blown the new tube? Could it be a dodgy connection/dry joint/tube power supply, lose valve seat? What can I check? Can anyone identify the main voltages and signals I should get where inside/at different ube socket pins? I haven't the time or money to try to send it away (unless there's really NOTHING I can do).
Any clues? Can I measure/check anything? what voltages should I get on which preamp tube socket pins? what can I check inside? I'll try ANYTHING. I NEED this amp to work NOW! We're currently trying to write and record new songs and I've now already missed the deadline for the demo we were trying to send out. I've got a multimeter/oscilloscope/etc. Could it have done something to have blown the new tube? Could it be a dodgy connection/dry joint/tube power supply, lose valve seat? What can I check? Can anyone identify the main voltages and signals I should get where inside/at different ube socket pins? I haven't the time or money to try to send it away (unless there's really NOTHING I can do).
Me
Member
Is the transformer on the right (when looking from the front) supposed to be quite warm to the touch after playing very quietly for a couple of hours? Maybe it is. I'm just trying to work out the problem...
Me
Member
Just swapped tubes 4 & 5 out again, and no change. I'm guessing it was just chance now that it worked before.
Me
Member
EDIT: These measurements were done relative to a bad ground point, see further down for proper measurements!!!
If it helps or gives any ideas at all here's the voltages on the different pins of the preamp tubes in standby (all in V unless noted). I assumed the 330mH Lehle thing was grounded to measured relative to that, so adjust according! I did this with the tubes in (from the other side), so let me know if it's more useful to measure elsewhere, or with the tubes pulled out. I assume it should be V4 since the FX is getting no send and it's on all channels, but here's the lot regardless:
V1
1 - 14.73
2 - 0
3 - 200mV
4 - 6.92
5 - 6.92
6 - 37.94
7 - -0.782
8 - 92.4mV
9 - 16mV
V2
1 - 35.52
2 - -200mV
3 - 115mV
4 - 6.92
5 - 6.92
6 - 6.92
7 - 0
8 - 482mV
9 - 24.1mV
V3
1 - 55.9
2 - 5.43
3 - 6.42
4 - 6.91
5 - 6.87
6 - 5.43
7 - 0
8 - 166.5mV
9 - 34mV
V4
1 - 56.0
2 - 34.2
3 - 34.7
4 - 6.91
5 - 6.92
6 - 34.2
7 - -0.5
8 - 107mV
9 - 37mV
V5
1 - 22.5
2 - 0
3 - 300mV
4 - 6.92
5 - 6.92
6 - 43.3
7 - -0.6
8 - 72.6mV
9 - 41.6
V6
1 - 33.71
2 - 5.44
3 - 226.5mV
4 - 6.92
5 - 6.92
6 - 33.0
7 - 5.55
8 - 6.99
9 - 43.2
Is pin 3 of V4 supposed to be that high? I have no idea how this things designed, it just seems noticably higher than all the other tubes?
If it helps or gives any ideas at all here's the voltages on the different pins of the preamp tubes in standby (all in V unless noted). I assumed the 330mH Lehle thing was grounded to measured relative to that, so adjust according! I did this with the tubes in (from the other side), so let me know if it's more useful to measure elsewhere, or with the tubes pulled out. I assume it should be V4 since the FX is getting no send and it's on all channels, but here's the lot regardless:
V1
1 - 14.73
2 - 0
3 - 200mV
4 - 6.92
5 - 6.92
6 - 37.94
7 - -0.782
8 - 92.4mV
9 - 16mV
V2
1 - 35.52
2 - -200mV
3 - 115mV
4 - 6.92
5 - 6.92
6 - 6.92
7 - 0
8 - 482mV
9 - 24.1mV
V3
1 - 55.9
2 - 5.43
3 - 6.42
4 - 6.91
5 - 6.87
6 - 5.43
7 - 0
8 - 166.5mV
9 - 34mV
V4
1 - 56.0
2 - 34.2
3 - 34.7
4 - 6.91
5 - 6.92
6 - 34.2
7 - -0.5
8 - 107mV
9 - 37mV
V5
1 - 22.5
2 - 0
3 - 300mV
4 - 6.92
5 - 6.92
6 - 43.3
7 - -0.6
8 - 72.6mV
9 - 41.6
V6
1 - 33.71
2 - 5.44
3 - 226.5mV
4 - 6.92
5 - 6.92
6 - 33.0
7 - 5.55
8 - 6.99
9 - 43.2
Is pin 3 of V4 supposed to be that high? I have no idea how this things designed, it just seems noticably higher than all the other tubes?
duesentrieb
Well-known member
I will direct Peter here . . .
Me
Member
Thanks. 
I'm taking it with me to work today. There's better facilities, oscilloscopes, audio analysers, and function generators, etc. If Peter can tell me what main things to check I'll put a sine wave in the front end and follow it through til it disappears!
I've got a customer in all day so I can't do anything at lunch time I'll have to wait until the end of the day unfortunately. I wonder if he'll notice I had about 4 hours sleep!
I'm taking it with me to work today. There's better facilities, oscilloscopes, audio analysers, and function generators, etc. If Peter can tell me what main things to check I'll put a sine wave in the front end and follow it through til it disappears! I've got a customer in all day so I can't do anything at lunch time I'll have to wait until the end of the day unfortunately. I wonder if he'll notice I had about 4 hours sleep!
duesentrieb
Well-known member
Did you put TungSols or Sovtek LPS into it? If so, they cannot handle the plate/cathode ratio of many modern amps and fail fast. And the Send is a CF (cathode follower), which has this ratio.
Additionally is your amp a 230 or 240V version. I suspect its a 230V running @ 240V looking at the heaters volts.
Additionally is your amp a 230 or 240V version. I suspect its a 230V running @ 240V looking at the heaters volts.
Me
Member
It's all Harma Drive-tested brand new from watford valves except a Cryogenically treated Philips JAN 7025 (I think!) as V1.
I bought my Herbie originally from Manson's in the UK as a 240V version they got straight from Diezel Germany S/N: 001/619. After I had problems with it blowing output valves and it went to see Peter Diezel twice and he couldn't find anything wrong with it (it may have just been the Ruby EL34s and I was very unlucky) he swapped it for another one. This one has a serial number 001/734 and you can see this one had a power tube bias resistor burn out and been repaired at some point as there's a burnt bit on the board underneath it, and the resistor is mounted slightly higher away from the board. This one definitely says 240V on the back, so the serial should match Diezels records as a 240V one. It blew Ruby EL34 output tubes too, but since I retubed it it's been fine until recently.
Was it correct to assume the Lehle thing's case is at 0V? If not then the heater voltage will be the difference between whichever valve pin is supposed to be 0V, unless I should remeasure all the voltages relative to a different place.
I bought my Herbie originally from Manson's in the UK as a 240V version they got straight from Diezel Germany S/N: 001/619. After I had problems with it blowing output valves and it went to see Peter Diezel twice and he couldn't find anything wrong with it (it may have just been the Ruby EL34s and I was very unlucky) he swapped it for another one. This one has a serial number 001/734 and you can see this one had a power tube bias resistor burn out and been repaired at some point as there's a burnt bit on the board underneath it, and the resistor is mounted slightly higher away from the board. This one definitely says 240V on the back, so the serial should match Diezels records as a 240V one. It blew Ruby EL34 output tubes too, but since I retubed it it's been fine until recently.
Was it correct to assume the Lehle thing's case is at 0V? If not then the heater voltage will be the difference between whichever valve pin is supposed to be 0V, unless I should remeasure all the voltages relative to a different place.
Me
Member
Me":3kd38x5o said:
My mistake V1 is a Cryogenically treated Philips JAN 5751. I get confused between 7025 and 5751!
Me
Member
duesentrieb":2jupvrtm said:
I think I tried a Sovtek as a replacement last night in V4 but it had Rubys in when this problem started, then an old RFT, then since last night (before the problem re-occurred) the Harma drive tested ECC83's.