Roadster use with 7-string guitar (if you can find the tubes that is)

bandit2013 said:

Those same tubes in the Mark V, may tighten things up a bit. I actually liked them better in the Mark IVB. Also had good results in the Mark VII too. Badlander as well. Not so lucky with the JP2C, made things sound a bit fizzy but that could have been the STR440 tubes (that is what the JP2C shipped with back in 2016). I should revisit them in the JP2C now that I have the STR415 Sylvania tubes in it.

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bandit2013 said:

V1, V3, V4, V5, V6. Tung Sol 12AX7 in V2 will make the edge mode on CH2 sound really good. Mullard long plate (current production) 12AX7 in V7 for the phase inverter. Some like the Sovtek LPS but the Mullard is the same tube but of better quality. Mesa stock is ok there as well. Best to have matched triodes for the phase inverter. The Mullard enhances the low end and top end with a good balance. The phase inverter tube is important and will influence tone.

What I ran in my Mark V90 was a bit different.
V1 and V3 were Svetlana 12AX7 (current production tubes, similar to the Mullard CV4004) They eliminated the 60Hz hum I was getting on the clean channel, it was so annoying, now it is completely gone. V2 I have a Tung Sol 12AX7, V4, V5, V6 were the Chinese Bejing tubes and V7 was a Mullard 12AX7 (current production, reissue long plate). I have had many issues with the Mark V90, so far I have yet to have the diodes fail. It is a 2012 so that particular year seemed to be prone with component problems. I do not favor the Mark V90 much. Not a bad amp but mine needs something fixed in it go correct the ice pick problem, I believe it may have more to do with the GEQ circuit than anything, it is not Just CH3, CH1 tweed, Ch2 edge were nasty ice pick makers too but the change in preamp tubes did help with that. I now like the edge mode, used to hate it. I still have an issue with CH3 though. I put the amp away out of sight and will get back to it later when I am ready to remove the main board to fix it. First, I will need to run test on a live preamp with an oscilloscope to see if I can locate the issue. Waveforms from the send jack were not correct, will have to check each gain stage to see if it is from that or is it from the GEQ circuit (which I suspect). Something is cutting the lower frequencies in the upper swing of the waveform. This is just a single frequency at 750Hz being injected into a Lehel P-split II with the isolated output used to drive the amp. This was to keep any DC voltages from passing into the front end. Also, did not want to find out what will happen to the function generator if there were any potential ground loop problems back feeding into the generator from the tube amp. That could damage both amp and generator. The Tera Echo was just a load on the FX loop, in a hard bypass mode.

View attachment 4624

It should look more like this (from the JP2C)

View attachment 4625

Originally , I was only doing a test to determine the signal levels from a few amps. At least I have some idea what may be going on with the V. Those peaks and drop out of the lower frequency on the upper portion of the waveform will have an ice pick tone. the bottom portion has more curvatures to it than the JP2C, that indicates some reduction in higher order harmonics. The flatter the curve, the higher the harmonic content is. Typical frequency harmonic range of the Mark III when I had the opportunity to run a signal analysis on it was 4th order before they dropped off. The order is a multiple of the original frequency. Even order harmonics will sound pleasing if you can get some roll off before you reach the 8th order or 8 times the fundamental frequency. Odd order harmonics sound harsh except for the 1st order which is only 1 x fundamental frequency. 5, 7, 9 will make things sound brittle. Note the sharp leading edge and the flat line on the upper waveform, it is not as sharp as it looks and the corners are well rounded on a close up view. That is with all of the JP2C controls set to noon. Not using the GEQ either but that is after the FX loop so its influence would not show up in the plots. The Mark V90 on the other hand uses the GEQ signal to create the FX send level so it will always be in the circuit even when turned off. Also it will be in the signal path in the FX loop hard bypass mode. so no way to avoid it if that is the root cause of the ice pick.

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Jolida is a company that is primarily known for its high-fidelity audio equipment, particularly tube amplifiers. They are based in the United States, but their products often feature components sourced from various manufacturers, including vacuum tubes.​

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Jolida-branded tubes, such as the 12AX7s you have, are typically sourced from established tube manufacturers like Shuguang in China. Jolida then brands these tubes with their name and sometimes applies additional testing or screening processes to ensure they meet certain standards for use in their audio equipment.​

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While Jolida is more recognized in the hi-fi audio world rather than the guitar amp community, their tubes can still be used in guitar amplifiers. The 12AX7 tubes you have, with the square foil getter, are indicative of the Chinese Shuguang production, which is known for making a variety of tubes that are commonly used in both audio and guitar amp applications. These tubes are generally considered good quality, and many musicians and audiophiles use them for their reliability and sonic characteristics.​

To get your Mesa Boogie Mark 5 90W, particularly in Mark IV mode, to sound more like the classic Mark IV tones from 90s Metallica and The Offspring, here are some specific tips:​

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### 1. **Tube Selection**:​

- **V1 and V3 (Svetlana 12AX7)**: These will give you a warm, balanced foundation, which is a good starting point for achieving that classic Mark IV tone. The warmth will help replicate the smoother yet aggressive sound of the Mark IV.​

- **V2 (Tung-Sol 12AX7)**: The Tung-Sol here will add brightness and punch, enhancing the clarity and attack, which is crucial for the tight, articulate chugging rhythms found in Metallica's sound.​

- **V4, V5, V6 (Chinese square foil getter 12AX7)**: These positions will help maintain the amp's gain structure and clarity, adding a bit of edge that can be beneficial in retaining the aggressive bite characteristic of the Mark IV tones.​

- **V7 (Mullard reissue long plate 12AX7)**: This will add a smoother, more harmonically rich tone in the phase inverter position, contributing to a fuller sound in both rhythm and lead tones.​

​

### 2. **Channel and Mode Settings**:​

- **Use Channel 3 in Mark IV Mode**: This is where you’ll be able to replicate the Mark IV sound most closely.​

- **EQ Settings**:​

- **Bass**: Set moderately low. On the Mark IV, the bass control often functions more as a low-mid control, so keep this tight to avoid muddiness.​

- **Midrange**: Set to a moderate or slightly boosted level. The Mark IV is known for its pronounced midrange, which is key to that 90s metal sound.​

- **Treble**: Adjust to taste, but keep it in the moderate range to ensure clarity without harshness.​

- **Presence**: This can be slightly boosted to add that cutting, aggressive edge.​

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### 3. **Graphic EQ**:​

- The Mark series is famous for its “V” shape on the graphic EQ. For Metallica and The Offspring tones, try a slight scoop in the mids with boosted lows and highs. Experiment with the exact settings to find the sweet spot, but generally:​

- **60 Hz**: Slightly boosted to add thump.​

- **240 Hz**: Cut moderately to reduce mud.​

- **750 Hz**: Cut significantly to scoop the mids.​

- **2.2 kHz**: Boost slightly for clarity and bite.​

- **6.6 kHz**: Boost slightly for brightness and sizzle.​

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### 4. **Cabinet Interaction**:​

- Your Mesa Dual Rectifier 4x12 cabinet with Vintage 30s is an excellent match for this tone. Vintage 30s are known for their tight lows, aggressive midrange, and detailed highs, which will complement the tone you're going for.​

- Position the cabinet and microphone (if you're recording or playing live) carefully. Off-axis mic placement can smooth out the highs, while on-axis placement can capture more of the aggressive bite.​

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### 5. **Playing Style**:​

- **Pick Attack**: To get the tight, percussive sound that Metallica is known for, focus on a sharp, aggressive pick attack.​

- **Palm Muting**: Use tight, controlled palm muting for that characteristic chugging rhythm sound.​

- **Lead Work**: For solos, the settings above should give you a smooth yet aggressive tone, with plenty of sustain and harmonic richness.​

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By combining these tube choices with the recommended settings, you should be able to dial in a tone that closely resembles the iconic Mark IV sound used by Metallica and The Offspring in the 90s. Adjust the EQ and presence settings to fine-tune the sound to your personal preference.​

• V3 = dc coupled cathode follower position: used as the tone stack driver. Chinese tubes, Meas 12AX7 (jj ECC83s), JAN/GE 12AX7WA will operate without issue. The Russian tubes have an isolation problem with the cathode and heater element. The tubes will fail prematurely in V3.
• V5 = cathode follower circuit used for FX driver (SEND) may also have issues with the Russian tubes. V3 is harder on the tube than V5.