Tan Ultrasound Build

[telentubes]

Wow. Gorgeous and an inspiration.

[dorrisant]

Looks fantastic!!

I solder everything on the bottom of the board... with lead wires attached to the board. Keeps the top side looking good.

[talbany]

Looks fantastic!!

I solder everything on the bottom of the board... with lead wires attached to the board. Keeps the top side looking good.

Yep I do too. If you apply the perfect amount of solder and keep the iron on it long enough it will form a perfect dome head solder joint. If you want to get the solder to shine you have to use the flux cleaner otherwise it will be a bit dull looking..That's the main reason why I use it as well as to get rid of all the smudge marks off the black board.it's the only thing I have found that gets that board to shine!
Next time I order board material it will be anything other than black. HATE IT!
Thanks Again!
Tony

[norburybrook]

Looks fantastic!!

I solder everything on the bottom of the board... with lead wires attached to the board. Keeps the top side looking good.

Yep I do too. If you apply the perfect amount of solder and keep the iron on it long enough it will form a perfect dome head solder joint. If you want to get the solder to shine you have to use the flux cleaner otherwise it will be a bit dull looking..That's the main reason why I use it as well as to get rid of all the smudge marks off the black board.it's the only thing I have found that gets that board to shine!
Next time I order board material it will be anything other than black. HATE IT!
Thanks Again!
Tony

ah, no ones revealed that secret before about the special flux cleaner etc. is there a window of time where this works? can I go back and clean up all my builds!!


may I ask if even seasoned pro's like you still are surprised and happy when an amp fires up first time without issues?

beautiful build

M

[martin manning]

IMO it shouldn't be necessary to clean a solder joint to get it to shine. Good (60-40) solder and good technique results in a smooth shiny joint, with just a little flux residue. The flux will sometimes spatter and leave a few tiny dots, which are easily cleaned up with an alcohol-dipped Q-Tip. Soldering from the bottom would minimize that, but I think I'd rather see what's happening on the top while I'm soldering. The glossy black boards look great, but I can see where they would show every smudge, and I'm afraid to use it due to some reports of the dyed material being conductive. Might be isolated quality issues, but it's natural color only for me.

[talbany]

may I ask if even seasoned pro's like you still are surprised and happy when an amp fires up first time without issues?

Sure it's always nice to see one fire right up out of the gate with no issues but I am not too disappointed when doesn't!. I rarely look at a schematic or a layout when I build these things so I usually expect something to be missed along the way. I can generally find some missed wiring pretty quickly. The things you don't want to have happen is to have a 1 bad part somewhere that becomes intermittent/ oscillates or simply causes the amp to just not sound healthy. A bad cap/pot or resistor can be the most challenging to track down in circuit. This is why IMO it's always good to throw a meter/scope and measure or test each part before it goes in.
Honestly, the most excited I get is when all my tubes come up evenly, stable and sound healthy with no issues (Especially 34's) and I don't have to take them back or go through several to find a good sounding quiet non-microphonic preamp tube That's when the cigars come out !..IMO it does not matter how long or how many you build it's always fun and exciting to bring another child into the world and even more exciting to share it here with my friends at the AG


I didn't know flux cleaner could get ya'll so excited ..Ahh the little things.

Tony

[dorrisant]

I'm pretty sure you can use the flux cleaner at any time down the road... I've used it in ancient amps just because I didn't want the custom thinking that I left that mess.

Like Tony mentions above, I get to a point where I feel it's ready to fire up and just do it. Sometimes, especially with a complicated build, it is a much quicker process to just figure out what you might have left out than to scrutinize every connection. Turn it on, check for red plating, then see what the symptoms reveal about possible errors... Use troubleshooting skills to finish. Sometimes there is nothing more to do than just play and enjoy.

[talbany]

Like Tony mentions above, I get to a point where I feel it's ready to fire up and just do it. Sometimes, especially with a complicated build, it is a much quicker process to just figure out what you might have left out than to scrutinize every connection. Turn it on, check for red plating, then see what the symptoms reveal about possible errors.

Although I do see your point in not spending too much time worrying about what you might have missed and if you do it's (sometimes) not a big deal to find it after it comes up
I would just add that an amp with 700V pumping through the output transformers primary I did scrutinize over every connection on that power supply board and went over it again and again and one last time checked all my grounds and only then did I bring it up very slowly monitoring both plate volt caps as well as bias voltage. it took me a few hours of cap testing/monitoring before I felt confident these caps were stable and fully reformed. So for this amp just flipping it on was out of the question!!
I know most out there will not be using old caps like I did..However, if you do plan on building one of these amps with the Music Man transformers you had better go over each connection when you are building this power supply and check it again! and check all your grounds and make sure no bare wires are too close to each other or to the chassis (700v will find ground) before you even think of firing it up..Even with new caps I would still bring it up slow and with a light bulb limiter.
Seriously if your new to building amps? build something else for a while first! If you are an experienced builder and want to take one on, be careful take every precaution you can think of down to your shoes and floor your standing on and wiring in your house! (does your wife know CPR?) when firing one of these up! 700V is no joke and will have you on the floor with your ears ringing before you even realize what it was you did wrong!

At 700V the sweet spot for your 34's should be around 25-28 mA cathode current draw that should give you (depending on the tube) roughly -30V of neg DC bias voltage needed. Since you are only using 1/2 the 70VAC winding that should give you -49V range to work with. This should be enough to put the tubes close to if not into cutoff. ALWAYS! set your bias voltage all the way up before firing it up..After you bring the amp up and everything looks ok then dial back the neg voltage while keeping an eye on your plate voltage and hopefully dropping you in right around 700VDC..
The Plate current rating on my TAD's are "23" The amplification rating is (TC) is "1081"
I needed -28.45 bias volts to get 25mA plate current with a bias range resistor of 33k running into an 8-ohm load and the presence control turned all the way up (No GNFB) dropping my plate voltage roughly 15/18 volts loaded conducting and idling.

Have Fun! and work Safe!

The guy with the clean boards.

[dorrisant]

I agree, Tony. I'm not trying to differ with you at all. I certainly do check over the power supply connections at least twice. If I catch something funny, I start checking again. Once I'm pretty confident about the PS, I do some preliminary checks, like making sure all plates are connected to the PS and that all grounds are made up. I didn't mean to minimize the situation, I still run it up on a variac slowly through a light bulb limiter without tubes, (except the rectifier if used) just in case. I verify reasonable voltages where they should be and then bring it up on the variac and bulb again. Once I bring it up without the variac and bulb, it just seems like all that's left is troubleshooting any of the minor problems.

[martin manning]

Nice post, Tony! Sound advice even for conventional power supplies.

[Matt J]

The build looks great!

How do you think having the LNFB on V1B affects the tone? I'm thinking about adding that to my #183 build (though it has a high plate preamp) to see how it sounds.

- Matt J.

[talbany]

I agree, Tony. I'm not trying to differ with you at all. I certainly do check over the power supply connections at least twice. If I catch something funny, I start checking again. Once I'm pretty confident about the PS, I do some preliminary checks, like making sure all plates are connected to the PS and that all grounds are made up. I didn't mean to minimize the situation, I still run it up on a variac slowly through a light bulb limiter without tubes, (except the rectifier if used) just in case. I verify reasonable voltages where they should be and then bring it up on the variac and bulb again. Once I bring it up without the variac and bulb, it just seems like all that's left is troubleshooting any of the minor problems.

Tony
I know your not! I also know you take it seriously and know you how to fire up an amp so my post was not at all directed at you or any 1 person. I just do not want anyone to get hurt

Tony

[talbany]

The build looks great!

How do you think having the LNFB on V1B affects the tone? I'm thinking about adding that to my #183 build (though it has a high plate preamp) to see how it sounds.

- Matt J.

Matt
A simple question with a not so simple answer!!

NFB does several things to the tone and feel!. The most obvious is, it flattens and extends the frequency response, it also reduces distortion generated in the V1B Stage, and it alters output impedance, increasing the damping factor, producing a "tighter" tone as well as affecting harmonic content due to lowering distortion.
Large amounts of Negative feedback can make an amp sound more solid-state like giving it more headroom and less sparkle on the top end (flatter response) and also makes the transition from clean to distortion more abrupt, as the negative feedback loop fails when there is insufficient forward loop gain to maintain itself. Whether or not to use feedback is a subjective matter!. In many ways, it acts very similar to GNFB in the output section, just in one stage of the preamp section. IMO 183 was designed to be a more aggressive bass-heavy sound (Especially in OD) so with that tone goal in mind the NFB loop should be omitted ..If you prefer an amp with more clean headroom tighter bass response and a smoother low end (Less Snarl) and a more refined sound then add in the loop!. High plates have more gain, therefore, more low end and slightly more headroom and with the knee shifted lower due to the higher input impedance combined with the Miller effect the stage already suffers from a flatter response (vs a high plate). This is why most guy's who prefer the AB Fender sound don't particularly care for the high plate sound and why I omitted the loop on all my high plate amps, the clean was just too flat sounding to me!. As for the Low plate amps, it really depends on what your shooting for. For a more aggressive rock sound, I like it off, for a more Jazz/fusion smoother flatter/cleaner compressed feel I like it in!. As for the OD in a low plate, I generally like the slightly smoother more refined less aggressive sound with the loop in
Again no right or wrong just what you are after. BTW..Of all the Dumble amps I have seen there does seem to be more loops in the earlier generation low plate amps, however, there seems to be no real correlation to him widely using it in any 1 design other than in his Dumbleators AFAIK!

Robben Ford said it best in a recent interview where he mentions one of the things he likes about 102's clean channel is its ability to stay tight and clean when he bangs out his chords,even at high vols! as well as the high end is there but never piercing or harsh to him it's "just right" he says. what he is talking about is some of the effects of the NFB loop on V1B

You can look it up I think it's a recent Premier Guitar Rig rundown interview.

If you have not messed with the loop much and are curious to experiment with its effects and want to see if it's something you will use put it on a switch.
Hope This Helps!

Tony

[Matt J]

The build looks great!

How do you think having the LNFB on V1B affects the tone? I'm thinking about adding that to my #183 build (though it has a high plate preamp) to see how it sounds.

- Matt J.

Matt
A simple question with a not so simple answer!!

NFB does several things to the tone and feel!. The most obvious is, it flattens and extends the frequency response, it also reduces distortion generated in the V1B Stage, and it alters output impedance, increasing the damping factor, producing a "tighter" tone as well as affecting harmonic content due to lowering distortion.
Large amounts of Negative feedback can make an amp sound more solid-state like giving it more headroom and less sparkle on the top end (flatter response) and also makes the transition from clean to distortion more abrupt, as the negative feedback loop fails when there is insufficient forward loop gain to maintain itself. Whether or not to use feedback is a subjective matter!. In many ways, it acts very similar to GNFB in the output section, just in one stage of the preamp section. IMO 183 was designed to be a more aggressive bass-heavy sound (Especially in OD) so with that tone goal in mind the NFB loop should be omitted ..If you prefer an amp with more clean headroom tighter bass response and a smoother low end (Less Snarl) and a more refined sound then add in the loop!. High plates have more gain, therefore, more low end and slightly more headroom and with the knee shifted lower due to the higher input impedance combined with the Miller effect the stage already suffers from a flatter response (vs a high plate). This is why most guy's who prefer the AB Fender sound don't particularly care for the high plate sound and why I omitted the loop on all my high plate amps, the clean was just too flat sounding to me!. As for the Low plate amps, it really depends on what your shooting for. For a more aggressive rock sound, I like it off, for a more Jazz/fusion smoother flatter/cleaner compressed feel I like it in!. As for the OD in a low plate, I generally like the slightly smoother more refined less aggressive sound with the loop in
Again no right or wrong just what you are after. BTW..Of all the Dumble amps I have seen there does seem to be more loops in the earlier generation low plate amps, however, there seems to be no real correlation to him widely using it in any 1 design other than in his Dumbleators AFAIK!

Robben Ford said it best in a recent interview where he mentions one of the things he likes about 102's clean channel is its ability to stay tight and clean when he bangs out his chords,even at high vols! as well as the high end is there but never piercing or harsh to him it's "just right" he says. what he is talking about is some of the effects of the NFB loop on V1B

You can look it up I think it's a recent Premier Guitar Rig rundown interview.

If you have not messed with the loop much and are curious to experiment with its effects and want to see if it's something you will use put it on a switch.
Hope This Helps!

Tony

Tony,
Thanks for the great response! It is a very opened-ended question without an easy answer! I’m building my ODS to be more on the aggressive rock spectrum (one of the main reasons I went with a high plate #183 design). My main guitar these days is a Tele I’ve heavily modified to work like an Esquire. I knew I needed something with a better bass response than the low-plate design I built a while back. However, I am curious to see how adding the LNFB would affect things, especially with playing chords in the clean mode like the RF quote you mentioned. So I’ve ordered the parts to wire it in and place it on a switch. I’m just going to have to see how it turns out. As for super-clean stuff, someday I hope to tackle a SSS design, but I’ll need to either buy or stamp my own chassis first.
Just part of the fun of tweaking these amps!
- Matt J.

[talbany]

My Tan Ultrasound Review
I am going to do this review while compairing it to a high plate Skyliner

So I finally had a chance to put the amp through it's paces today since the wife went off to a family reunion today
Here is some amp specs and some settings
Plate voltages shake out
Plates 697
Screens 358
V3ab 290 input 285 NFB side Balanced it out
V2ab 214/212
V1ab 210/207
Tube compliment
Mullard Blackburn 163 V1 and V2
Telefunkin Smooth Plate PI
Tad EL-34B's
Sweet Spot Settings
OD input trim 24.6K w/ amp on
Input Vol 1oclock
Treb 2 oclock
Mid 12 oclock
Bass 2 oclock
Drive 11 oclock
Vol 11/12 oclock
Mstr 9 oclock
Pres 3 oclock
Pot tapers are 30% accept Mid and Bass pots.
Custom Shop Strat w/Seymore Duncan SSL-1 SSL-5 bridge
Less Paul Classic 92/w Fralin Custom wound for my D-Style amps
Marshall 4X10 closed back Vintage with stock white label 35 watt speakers
2X12 Semi Open Cab loaded G-12 65's

First impressions are the amp is loud and proud with plenty of headroom with all the controls having plenty of range acting as per skyline specs. The presence control is a little sensitive and comes on strong after about 9 o'clock. This is the typical Dumble presence control response time
The clean channel (w/NFB loop) acts typical Dumble with everything flattening out along with the increase in headroom on the clean channel. There is no harshness anywhere to be found in the amp and even with the bright switch on there is plenty of highs but no ice pick and easy on the ears.The amp responds fast the bass is tight but not at all stiff feeling. Overall well balanced and works well with both Humbuckers and Singles.
Going between the MK'3 plate resistors and the NOS Dales, I prefer the Dales since they add that bit of glass on the top end (chirps) without growing any hair or worse a buzzing or harsh top end with the front end pushed like the newer Dales can get!
The MK'3's were more neutral sounding and are still a perfectly good sounding resistor.For a more aggressive sound without the loop I would go with the MK'3 for that sound! ala 183.
The clean sound on this amp does not seem to want to sustain out and bloom as well as my High plate amps do.Since the amp is a low plate and uses 34's the clean channel is more "boxy" sounding vs a standard 6L/Skyline version. This is the thing that I miss the most in this amp so for this I would have to say I prefer the 6L's big round bottom better as a clean tube in really just about any amp IMO.
The clean channel doesn't seem to be too picky with preamp tubes probably because I have the NFB loop in just pick something with good gain specs so it's not too flat sounding.
The boost in this amp is too boxy sounding. It's not as bad with humbuckers but with a Strat I am going to have to bleed in some low end to try and fill it out a bit more. The volume boost it gives me is perfectly useable!
Overdrive Side
It took me a while to find a good sounding matched tube for the channel but it made a huge difference!. The OD has plenty of gain on tap. It can get either smooth or aggressive depending on where you set it. The highs chirp are clear not at all harsh very musical sounding. A light touch is all you need in fact the lighter you play the more the amp wants to take off. Although a rock player could get away with using this amp I would put this in more of a jazz type or fusion type player that is going for a less aggressive and more compressed/smoother type vibe. The transition between the clean channel and OD is very transparent as the OD just sounds BIGGER with more of the same.

Overall
Although I do prefer the big round bottom of a 6L (especially clean) The clean side of this amp is IMO closer to that of a Fender/Showman sound even with the NFB on V1b than that of a high plate and subbing out the 34's for 6L's would get me even closer if I want to go there. For me personally, I've always preferred the OD sound of the High Plates. Although this amp doesn't have that low mid growl of the high plates It gets me in the ballpark and with the humbuckers can still get it to flutter on certain low notes. Overall I still like the high plates better for OD but prefer the glassier top end clean side with the low plates (w/Dales) so overall It's a trade-off,,
I've had this problem with low plate skylines in the past with the OD being a bit thin in the mids at times (especially with single coils and at low vol levels). I could never figure out why my amps did not sound anything like the clips of the original low plate ODS amps I have been hearing live and on the net didn't seem to be as thin sounding. This amp is the closest one I've built that sounds like the originals. The only thing I can credit this too is the attention to detail with respect to parts selection in the preamp section. Even the switch between the MK’3s and the Dales were well rather surprising
As far as the Music man output section is concerned obviously is subjective however the 34’s yield a smoother transition into distortion than the 6L’s do and gives you that fat creamy mid range they are famous for. The amp has this in spades however those qualities don't come full force until the 34’s are pushed into clipping so at this point the amp is really too loud for me to use at any of my smaller gigs.I would be run off the stage at this volume level!!.. I will say that the amp in clean or OD pushed to point of output tube saturation everything fills out nicely stay's well balanced and with the Les Paul was really quite incredible I had to laugh.
Bottom Line!
I’ve built just about every D-Style OD amp over the years and that my main take away has been that they all wonderful musical instruments each in their own way. You are assured to find one that really inspires you throughout the various generations. They are well designed very reliable and all a blast to play, however having built and played almost all the designs I have yet to find just 1 design that does everything in every musical situation I come upon. For some things I prefer the low plates, others high plates. sometimes I prefer 34’s other times 6L’s or even KT88’s. Overall though I am pleased with how the OD in this amp turned out and if I were an independent artist playing big rooms and were able to just have my one sound I was known for I could be perfectly happy just using this amp and see why this amp was loved by so many players!. Apart from possibly trying some NOS glass tubes and tweaking the boost sec I am keeping it just as it is and looking forward to seeing where it takes me musically
That's my advice. Yours can of course very!..I will try to get some clips out soon.I hope this sheds some light on the Music Man 34 Low Plate Skyliner design!
Please let me know if you have any questions!

Tony