New Bluesmaster (Pics soon)

[dogears]

No lambasting, but I would not change from the established values until we determine why he is experiencing these issues. I have played more than a half dozen Bluesmasters including a real Dumble one. None were too bass heavy on the cleans (unless you foolishly MUST use a neck humbucker all the time). There is another issue or he is using the neck bucker all the time. No other explanation.

Running a 100k bass pot with 400k tail is taking you in the wrong direction. Keep in mind that a passive tone stack works by blleding off frequencies to ground.

At the risk of straying to far from "established" values, here are my recommendations for taming a bass-heavy bluesmaster. I'd also recommend doing them in this order. Assuming you already use a .01uF coupling cap on V1b:
1. Go back to the 1uF bypass cap on V1b.
2. Increase the value of the slope resistor. Try 56k but you may need to go as high as 100k to hit your sweet spot.
3. Change the treble pot to 250KB. (250KA sounds too dark to me.)
4. Last resort, change the bass pot from 500KA to 250KA. (Shouldn't be necessary after the above changes, but can help things along.

OK, gotta go duck outta sight before dogears lambasts me.

[tonejunkie]

Ok, I'm not using the neck bucker all of the time and with either the neck bucker or bridge if I turn the bass past 4 even with this 400k 100k pot thing you could not play the bass notes in a band setting unless you wanted everyone to stop and ask you what the heck was that. Could you guys tell me where your bass is set on the clean channel.


Also did anyone check out the differences between the schematic I used and the example of the boost circuit. Which one is correct?

[ayan]

Ok, I'm not using the neck bucker all of the time and with either the neck bucker or bridge if I turn the bass past 4 even with this 400k 100k pot thing you could not play the bass notes in a band setting unless you wanted everyone to stop and ask you what the heck was that. Could you guys tell me where your bass is set on the clean channel.


Also did anyone check out the differences between the schematic I used and the example of the boost circuit. Which one is correct?

Not to confuse matters even more, but I think perhaps the iron (OT, specifically) in question may play a role here. All other things equal, with a regular Fender Twin Reverb tye of OT, the same BM amp will sound more "balanced" than one with a High Power Twin (larger) OT. If you like everything, i.e., the texture of the tone, the balance between clean and OD and the texture of the breakup on the bass side of things, then I would suggest you try decreasing the value of the PI input cap (.022uF) and see if that gets you there. Changing things in the preamp will alter everything, the balance between clean and OD and the character of the OD. So, the later you make the changes to reduce some of the bass, the "better."

Two more things. Moreso than any other Dumble build I have dabbled with, the BM is a very picky mofo. Got the amp sitting next to me and through a closed back 1x12 with an EVM 12L reissue, it sounds thumpy but very cool in a rock and roll type of way. Through an open abck 1x12 with an old EVM 12L Series II speaker, the same amp sounds like crap in overdrive mode. Really, a very picky amp...

Last but certainly not least. I had been using a .001uF coupling cap between OD1 and OD2, knowing too well that Scott and Chris S. like a higher value there. Well, I HAD to try it and so this afternoon I put a .002uF there... Huge difference in the texture of the OD, definitely a step in the right direction for the RF thing with humbuckers. On the downside, not sure I like it better for a Strat. But, you can try that as well. I ended up dialing back the bass on the HRM to accommodated the difference, but it is the texture of the bass breakup that is much cooler with the .002uF cap.

Good luck and happy experimenting,

Gil

[talbany]

Not to confuse matters even more, but I think perhaps the iron (OT, specifically) in question may play a role here. All other things equal, with a regular Fender Twin Reverb tye of OT, the same BM amp will sound more "balanced" than one with a High Power Twin (larger) OT.

Not to Derail here..

I've not yet built a Bluesmaster w/ HP Twin OPT.. so no opinion there.. I have built several Non HRM's w/ HP Twin with excellant results and do recommend them over the standard Twin Iron.. With a quad of Solvtek 5881's pretty sweet sounding.. If you can pick up a decent used one for a good price I recommend it.. I think I heard Robben has one in one of his Dumbles.. If I am wrong please correct.... Thanks.



Tony VVT

[Structo]

Tony,
What does the HP signify?

[talbany]

High Powered..135w Twin.. These are the ones with the UL taps... Just tie them off.. Mo Iron!!


You can also use these for OPT transformers on the Music Man's....They will handle the 700v.. I've built 2 and so far rock solid on the road almost a year... Some people will argue the impedance won't be correct due to the higher voltages... I could care less transformer doesn't get hot and the tone is Killin.. 4 OHM tap... w/Solvtek 5881's or Tung Sol 6L.winged C's...ROCKS!!


Tom Check your inbox>>>




Tony VVT

[DonMoose]

Some people will argue the impedance won't be correct due to the higher voltages

Silly people, maybe. DC does not affect the AC impedance.

[dogears]

This is not true Don Moose.

The Music Man output has an impedence that is over 2X higher than a standard 6L6 output. Check what the plate to plate impedence of a 6L6 is at 680V. Theoretically, you will want a tranny with a much higher impedence. Of course, as Tony points out, there is no definative wrong. On the other hand, in A/B testing, he may prefer real Music man iron over the HP Twin iron at 700V.

Did you compare trannies Tony?

Some people will argue the impedance won't be correct due to the higher voltages

Silly people, maybe. DC does not affect the AC impedance.

[talbany]

I think I tried a while back to get a thread going on this subject when I was doing these builds but got no response on the subject...Everyone here hates me I know!! LOL!!

The Music Man output has an impedance that is over 2X higher than a standard 6L6 output. Check what the plate to plate impedance of a 6L6 is at 680V. Theoretically, you will want a tranny with a much higher impedance. Of course, as Tony points out, there is no definitive wrong. On the other hand, in A/B testing, he may prefer real Music man iron over the HP Twin iron at 700V.

Did you compare trannies Tony?

To be honest when I installed the transformers I had every intention on not liking the results...I even looked for reasons.. Hell even Paul at Mercury Mags offered to send me one of there MM fat stacks.. since it was my own personal amp..I had to say I was surprised.. Not an ounce of grain in the tone tight low end..and a softer mellow top..which I kinda dug....So to answer your question with regards to the 100 watt no I did not see the need.. I did however try this on a 50 watter with MM power and a Bassman 75 OPT.. and thought the MM 5-75 POT sounded better.. A crisper more articulate top..The Bassman was too dark on the top..
If I had to give an opinion here on how I thought all this translated into tone I would say the the transformers with the lower primary impedance (in relation to the higher plate voltages) translates to for a lack of a better word a less bright amp.. It worked with the 100 but not the 50..
Did any of this make any sense!!


Tony VVT