Gulsekt-88!
Moderators: pompeiisneaks, Colossal
Re: Gulsekt-88!
(deleted)
Last edited by matt h on Fri Mar 27, 2015 4:40 pm, edited 1 time in total.
Re: Gulsekt-88!
^Hey, thanks Matt! I've learned a LOT around these parts, and seriously thank every one of you very much!
Here's an update!
It had a hum problem, a dropping R that was not there because of an error upon looking at the layout of the Yeti between the 1st filter cap (Phase inverter) and the 2nd filter (CF and Stage 3). It's now much quieter. Whoda thunk?
The squeal issue has pretty much been dealt with. I had the crappiest of el-cheapo 12AX7's in there initially, as of right now there's a Telefunken long smooth plate in V1, and RCA black plate 5751's in V2 & V3. (Don't judge me!)
There was the issue of a little fizzy, and way too bassy. Long story short, dropped the 2nd to 3rd stage coupling cap to a .002, and dropped the .1's off the PI to .02's. I think that's all I did for the bass issue, I'll have a schem with everything updated soon.
I play drop C mostly (CGCFAD) with active pickups. (I'm pretty sure I'm one of the oddballs here as far as musical tastes.) So there's plenty of low end going in already, it doesn't need to be exacerbated.
Low end is now under control, clear and intelligible notes while palm-mute shredding the lowest of lows.
For the fizz department there is now a 100pf grid to plate on V1A, the cut control was increased from a 47pf to 330pf, and the bypass cap on stage 3/V2B was removed.
Much better, but still, there is something that seems to plague my ears on most amps I play. Somewhere around 8-9k there is a distortion harmonic characteristic fizz that I'd love to just choke out. I'm aware of many remedies, but none seem to do the trick without sucking the life out of the top end as a result. Does anyone have a suggestion? Perhaps a simple 1 band parametric, that I'd love a schematic of?
So, after tonight we're sitting pretty with the Gulsekt-88. I'll tell you right now, this is not a gentleman's amp! No clean to really speak of, it's straight pissed off, for the most part. But, a lot of tonal and characteristic shaping is completely achievable, as is, right now, just nothing really laid back.
Still and yet to come, is clipping diodes and other assorted candies, the "simple noise gate", and another switch that caught my attention... I plan on making a video solely of these clipping components that I have and their characteristics. I have so many to test, and I don't want to hog the info on what sounds like what!
So many things are still on the tweaking block!
Feel free to chime in, suggest, yell, dull roar, or do whatever you'd like. Can't wait for y'all to hear it.
Here's an update!
It had a hum problem, a dropping R that was not there because of an error upon looking at the layout of the Yeti between the 1st filter cap (Phase inverter) and the 2nd filter (CF and Stage 3). It's now much quieter. Whoda thunk?
The squeal issue has pretty much been dealt with. I had the crappiest of el-cheapo 12AX7's in there initially, as of right now there's a Telefunken long smooth plate in V1, and RCA black plate 5751's in V2 & V3. (Don't judge me!)
There was the issue of a little fizzy, and way too bassy. Long story short, dropped the 2nd to 3rd stage coupling cap to a .002, and dropped the .1's off the PI to .02's. I think that's all I did for the bass issue, I'll have a schem with everything updated soon.
I play drop C mostly (CGCFAD) with active pickups. (I'm pretty sure I'm one of the oddballs here as far as musical tastes.) So there's plenty of low end going in already, it doesn't need to be exacerbated.
Low end is now under control, clear and intelligible notes while palm-mute shredding the lowest of lows.
For the fizz department there is now a 100pf grid to plate on V1A, the cut control was increased from a 47pf to 330pf, and the bypass cap on stage 3/V2B was removed.
Much better, but still, there is something that seems to plague my ears on most amps I play. Somewhere around 8-9k there is a distortion harmonic characteristic fizz that I'd love to just choke out. I'm aware of many remedies, but none seem to do the trick without sucking the life out of the top end as a result. Does anyone have a suggestion? Perhaps a simple 1 band parametric, that I'd love a schematic of?
So, after tonight we're sitting pretty with the Gulsekt-88. I'll tell you right now, this is not a gentleman's amp! No clean to really speak of, it's straight pissed off, for the most part. But, a lot of tonal and characteristic shaping is completely achievable, as is, right now, just nothing really laid back.
Still and yet to come, is clipping diodes and other assorted candies, the "simple noise gate", and another switch that caught my attention... I plan on making a video solely of these clipping components that I have and their characteristics. I have so many to test, and I don't want to hog the info on what sounds like what!
So many things are still on the tweaking block!
Feel free to chime in, suggest, yell, dull roar, or do whatever you'd like. Can't wait for y'all to hear it.
Re: Gulsekt-88!
(deleted)
Last edited by matt h on Fri Mar 27, 2015 4:40 pm, edited 1 time in total.
Re: Gulsekt-88!
Yes, here is an update indeed.
I spoiled Matt and showed him just how insane and versatile this amp can get as is, but we're still very much in tweak phase! I made a special clip just for the TAG bretherin here, to showcase some Gulsekt for your ears.
I took it easy on the crazy, the guitar is a Jackson DK2S, bridge position is a Seymour Duncan something, I'm thinking it's a Super Distortion? The guitar is not mine, It's my Dad's, and he's just like me and doesn't remember anything... Middle position is a DiMarzio Hot rail, by the looks of it.
Cabinet is a 15 ply all around birch cabinet 2x12, V30's, large diaphragm Groove Tubes condenser on the top, cardioid Beyerdynamics M88 on the bottom. These go into a couple nice tube mic preamps, into ProTools. This setup captures the sound quite nicely to what I hear in the room.
This guitar is tuned to... *gasp* E standard!
We found that 440 tuning sounds really nice on this amp, even though I severed the low end so severely having been testing it with a drop C tuned guitar. (That's what I play, hey, to each their own, right?) Thing is, in normal tuning it's not at all a total whimp in the low end spectrum. Kinda scares me, and you'll see what I mean if you look at the attached totally revised schematic. Those coupling caps are tiny!
Does anyone see something that may be creating/allowing more low end in this amp than necessary? I've cut so much, and even an E standard guitar just sounds "normal" to me, with low end to spare even. When I plug in a drop tuned guitar, it gets a touch muddy.
Lowering the coupling caps or the .022's in the CF leaves it sterile and weak sounding, I can tell we're bottoming out there...
The rotary knob of diodes etc. is now installed, I'm trying to find a happy spot with it in the amp with respect to gain levels and so on... That's a "me learning the amp, with added benefits" thing, as it is currently. Being that it's so high gain as it is, I'm not sure this is beneficial or not, I've yet to be proven wrong, bear with me on the "here's what a ton of different clipping things on a knob sound like" play-through video...
In the sound clip, from start to about 50 seconds is the bridge/middle pickup, then switches to just bridge. For the most part, it starts clean, and ends mean. Pardon my ill playing, standard tuning is kind of alien to me after all these years of being in drop somethingoranother... (Plus, I kinda am not that gloriuus to begin with...)
I would like to add, that this amp is indeed surprisingly "touch sensitive" I know quite the debate on this subject is going on right now, so this is what I mean be that term; The amplifier is sensitive to my touch. Depending on pick attack, slight palm mute, angle of the pick, how tense said pick is held, it can be heard. (I tried to showcase this a couple times in the audio sample)
A couple little ideas;
- Split load resistor with dedicated coupling caps for standard tuning passive pickup vs. active pickup drop tuning, ala fast/gradual, Komet, (You know..).
- Increasing 1st filter cap at the rectifier a smidgen
- That .1 cap at the input
Hear it! :
https://soundcloud.com/agormortisrr1/ne ... kt-preview
.
I spoiled Matt and showed him just how insane and versatile this amp can get as is, but we're still very much in tweak phase! I made a special clip just for the TAG bretherin here, to showcase some Gulsekt for your ears.
I took it easy on the crazy, the guitar is a Jackson DK2S, bridge position is a Seymour Duncan something, I'm thinking it's a Super Distortion? The guitar is not mine, It's my Dad's, and he's just like me and doesn't remember anything... Middle position is a DiMarzio Hot rail, by the looks of it.
Cabinet is a 15 ply all around birch cabinet 2x12, V30's, large diaphragm Groove Tubes condenser on the top, cardioid Beyerdynamics M88 on the bottom. These go into a couple nice tube mic preamps, into ProTools. This setup captures the sound quite nicely to what I hear in the room.
This guitar is tuned to... *gasp* E standard!
We found that 440 tuning sounds really nice on this amp, even though I severed the low end so severely having been testing it with a drop C tuned guitar. (That's what I play, hey, to each their own, right?) Thing is, in normal tuning it's not at all a total whimp in the low end spectrum. Kinda scares me, and you'll see what I mean if you look at the attached totally revised schematic. Those coupling caps are tiny!
Does anyone see something that may be creating/allowing more low end in this amp than necessary? I've cut so much, and even an E standard guitar just sounds "normal" to me, with low end to spare even. When I plug in a drop tuned guitar, it gets a touch muddy.
Lowering the coupling caps or the .022's in the CF leaves it sterile and weak sounding, I can tell we're bottoming out there...
The rotary knob of diodes etc. is now installed, I'm trying to find a happy spot with it in the amp with respect to gain levels and so on... That's a "me learning the amp, with added benefits" thing, as it is currently. Being that it's so high gain as it is, I'm not sure this is beneficial or not, I've yet to be proven wrong, bear with me on the "here's what a ton of different clipping things on a knob sound like" play-through video...
In the sound clip, from start to about 50 seconds is the bridge/middle pickup, then switches to just bridge. For the most part, it starts clean, and ends mean. Pardon my ill playing, standard tuning is kind of alien to me after all these years of being in drop somethingoranother... (Plus, I kinda am not that gloriuus to begin with...)
I would like to add, that this amp is indeed surprisingly "touch sensitive" I know quite the debate on this subject is going on right now, so this is what I mean be that term; The amplifier is sensitive to my touch. Depending on pick attack, slight palm mute, angle of the pick, how tense said pick is held, it can be heard. (I tried to showcase this a couple times in the audio sample)
A couple little ideas;
- Split load resistor with dedicated coupling caps for standard tuning passive pickup vs. active pickup drop tuning, ala fast/gradual, Komet, (You know..).
- Increasing 1st filter cap at the rectifier a smidgen
- That .1 cap at the input
Hear it! :
https://soundcloud.com/agormortisrr1/ne ... kt-preview
.
You do not have the required permissions to view the files attached to this post.
Re: Gulsekt-88!
Isn't the main purpose of the .1uF cap on the input, to block RFI?
The amp has come a long way!
The amp has come a long way!
Tom
Don't let that smoke out!
Don't let that smoke out!
Re: Gulsekt-88!
No, it is to keep DC off the guitar's volume pot. This is usually necessary when the input gain stage plate resistor value is very high.Structo wrote:Isn't the main purpose of the .1uF cap on the input, to block RFI?
Great job Meat and Beer! The Randy Rhoads riff sounds excellent. Plenty of gain on tap.
-
David Root
- Posts: 3540
- Joined: Fri Aug 04, 2006 3:00 pm
- Location: Chilliwack BC
Re: Gulsekt-88!
Fine attitude M&B! High gain heaven!
Re: Gulsekt-88!
Proto-phase is probably about 96% complete! For those interested, I thought I’d give a what’s been happening, where we are, and what’s next kinda update thingy. (Broken down into sections cause it’s a big pile…)
Tone stack/voicing;
This amp is now “designed for low tuned guitars” with the ability to make standard tuning sound fantastic also. (But of course) The “Freq Tweak” (Adjustable slope R) Didn’t tickle the ol’ fancy, so I went with the value of the position always left in, being 85k. Also put a 100k with the 85k on a switch, (may go 110k?) so now we have a mid shift switcheroo instead.
Put in a stack lift switch. Gives up just a teensy bit more gain, but what I really liked about it, is it opens up the amp a bunch. More mids, more throaty growl. (Big fan of the mids, right here.)
Simple Noise Gate;
This thing is fantastic!!!! I’ll attach the ‘matic for those who may be unaware of it. (Props to Mr. Manning, I originally heard it from him. Thanks!) Absolutely transparent when you’ve got a little gain going. You can hear it working a little when you play clean, but I just turn it off when audible. I really never play this thing clean anyway, (Nor in general) it wasn’t designed to do those things at all. For what it is parts-wise, I really encourage people to try it out for themselves.
Local Negative Feedback (Variable and defeatable);
This is the real game changer here. The amp used to be REALLY low end dominant, and with lower tuned guitars, it was really hard to get the bass focused for low string riffing. This will roll the low off starting from the lowest end, and you can move the curve further up the spectrum to the sweet spot, gain dependant. This function reduces gain, but more than makes up for its usefulness. That’s kind of, more or less, what my ears are telling me it’s doing anyway.
Bootstrap Boost;
LNFB reduces gain a bit, but no biggie, cause we gave it more by upping the plate R’s a bit! Nice smooth increase in the upper mid/treble area without adding harsh fizz. (For those wondering, I hear zero noise from the neon bulb protection, and it works like a charm!)
PPIMV;
Optimized the original LaMar MV values for what suits the SE KT88 better. Happy tubes make happy guit-fiddlers.
Zobel/Conjunctive Filter;
Yep, one of those. For this amp, it was not at all a “blanket” like some have experienced. It went on the primary side, adjusted the cap to taste, and let it rip. From what I surmise, these are frequency compensation networks, meant to flatten out the response delivered to the load it sees. The top end was smoothed out, less fizzy shitty, as well as the low end became more manageable. This is a very subtle difference, but it’s quite pleasant on the ear holes.
Diode Clipping Rotary;
Didn’t make the cut. I had high expectations for this! It very well may be that it just simply isn’t right for this amp, it may well be I did it wrong. (Rather simple thing to mess up, but anything’s possible…) It really didn’t yield anything close to that what you can hear in ampgeeks thread in the Marshall section (JCM800/2204 build). Sure, they cut signal, that we both had in common, but mine didn’t sound nearly as cool.
I still have the small enclosure I built the circuit in, so perhaps another time, another build. Diodes range from 6v’s – 24v’s, red LED, two pairs of transistors… Maybe it needs to be more complicated than just a pair of things, and more like sir ampgeeks arrangements. (?)
---------------------------------------------------------------------------------------------------------------------------------------------------------------
In the amp now, are generic polypropylene coupling caps, but I now have a complete set of OD’s for the amp… I’ve been waiting to swap them out until this point in the build was reached… Yay, comparison recording!
New layout design is in the works for the new chassis, and I got a pretty cool idea for the finished product!
Before the transition into the final, I still need to do something with the “output to something” hanging off the PI. I’m thinking a variable line level, and perhaps even a variable mic level. (I have some decent mic pre’s in mah rack, seems like a neat and versatile idea. XLR jack and all.) Any thoughts on that?
Some recordings will be made in the near future! I've been getting back into playing more instead of constant amp tweaking/building, and have been learning most of a song by a band that makes me happy that will showcase exactly what this amp was really designed to do. The metal shred!
I’m sure you’re all thrilled. C’mon, bang your head just a little?
Tone stack/voicing;
This amp is now “designed for low tuned guitars” with the ability to make standard tuning sound fantastic also. (But of course) The “Freq Tweak” (Adjustable slope R) Didn’t tickle the ol’ fancy, so I went with the value of the position always left in, being 85k. Also put a 100k with the 85k on a switch, (may go 110k?) so now we have a mid shift switcheroo instead.
Put in a stack lift switch. Gives up just a teensy bit more gain, but what I really liked about it, is it opens up the amp a bunch. More mids, more throaty growl. (Big fan of the mids, right here.)
Simple Noise Gate;
This thing is fantastic!!!! I’ll attach the ‘matic for those who may be unaware of it. (Props to Mr. Manning, I originally heard it from him. Thanks!) Absolutely transparent when you’ve got a little gain going. You can hear it working a little when you play clean, but I just turn it off when audible. I really never play this thing clean anyway, (Nor in general) it wasn’t designed to do those things at all. For what it is parts-wise, I really encourage people to try it out for themselves.
Local Negative Feedback (Variable and defeatable);
This is the real game changer here. The amp used to be REALLY low end dominant, and with lower tuned guitars, it was really hard to get the bass focused for low string riffing. This will roll the low off starting from the lowest end, and you can move the curve further up the spectrum to the sweet spot, gain dependant. This function reduces gain, but more than makes up for its usefulness. That’s kind of, more or less, what my ears are telling me it’s doing anyway.
Bootstrap Boost;
LNFB reduces gain a bit, but no biggie, cause we gave it more by upping the plate R’s a bit! Nice smooth increase in the upper mid/treble area without adding harsh fizz. (For those wondering, I hear zero noise from the neon bulb protection, and it works like a charm!)
PPIMV;
Optimized the original LaMar MV values for what suits the SE KT88 better. Happy tubes make happy guit-fiddlers.
Zobel/Conjunctive Filter;
Yep, one of those. For this amp, it was not at all a “blanket” like some have experienced. It went on the primary side, adjusted the cap to taste, and let it rip. From what I surmise, these are frequency compensation networks, meant to flatten out the response delivered to the load it sees. The top end was smoothed out, less fizzy shitty, as well as the low end became more manageable. This is a very subtle difference, but it’s quite pleasant on the ear holes.
Diode Clipping Rotary;
Didn’t make the cut. I had high expectations for this! It very well may be that it just simply isn’t right for this amp, it may well be I did it wrong. (Rather simple thing to mess up, but anything’s possible…) It really didn’t yield anything close to that what you can hear in ampgeeks thread in the Marshall section (JCM800/2204 build). Sure, they cut signal, that we both had in common, but mine didn’t sound nearly as cool.
I still have the small enclosure I built the circuit in, so perhaps another time, another build. Diodes range from 6v’s – 24v’s, red LED, two pairs of transistors… Maybe it needs to be more complicated than just a pair of things, and more like sir ampgeeks arrangements. (?)
---------------------------------------------------------------------------------------------------------------------------------------------------------------
In the amp now, are generic polypropylene coupling caps, but I now have a complete set of OD’s for the amp… I’ve been waiting to swap them out until this point in the build was reached… Yay, comparison recording!
New layout design is in the works for the new chassis, and I got a pretty cool idea for the finished product!
Before the transition into the final, I still need to do something with the “output to something” hanging off the PI. I’m thinking a variable line level, and perhaps even a variable mic level. (I have some decent mic pre’s in mah rack, seems like a neat and versatile idea. XLR jack and all.) Any thoughts on that?
Some recordings will be made in the near future! I've been getting back into playing more instead of constant amp tweaking/building, and have been learning most of a song by a band that makes me happy that will showcase exactly what this amp was really designed to do. The metal shred!
I’m sure you’re all thrilled. C’mon, bang your head just a little?
You do not have the required permissions to view the files attached to this post.
Re: Gulsekt-88!
Interesting side notes about this here Gulsekt-88
Story 1;
It got the cops called on me! This “little” 20 watter got my presence graced by the authorities one night while working on its low end. (Somewhere around 2am. Hey, I work nights!) Turn the amp on, chug chug chug for maybe a minute, amp off. Tweak, repeat. Sure, it was really bassy, and turned up ALL THE WAY, but think about this…
I’ve had 100 and 120 watt tube heads rippin at that time in the morning, for way more than a minute or two at a time in a few intervals. No issues for 7 months until now. I don’t live in an apartment complex, and our neighbors aren’t right on top of us at all. Bummer! But, wow, 20 watts is still pretty loud, ay?
Story 2;
We had company a few nights ago. One fella, good friend and also a big metal fan and his lady. I showed him my newest acquisition (Engl Savage 120) and the Gulsekt88, as he had never heard either of them yet. Went through all the features of all four channels of the Engl, moved to the Gulsekt and showed that off a bit, and asked him if he’d like a crack at it.
Sure! Ok, cool, what do you want to plug into? “That one, it just sounds better.” That one? Was the Gulsekt88. Probably about a $200 investment so far, beat out a $2,000 big league amp. I did not expect that at all, and wasn’t staged in the least. Just a couple buddies havin fun with toys, hanging out.
Wow.
I’ve got a feeling this Ghetto-UL thing is gonna catch on!
Story 1;
It got the cops called on me! This “little” 20 watter got my presence graced by the authorities one night while working on its low end. (Somewhere around 2am. Hey, I work nights!) Turn the amp on, chug chug chug for maybe a minute, amp off. Tweak, repeat. Sure, it was really bassy, and turned up ALL THE WAY, but think about this…
I’ve had 100 and 120 watt tube heads rippin at that time in the morning, for way more than a minute or two at a time in a few intervals. No issues for 7 months until now. I don’t live in an apartment complex, and our neighbors aren’t right on top of us at all. Bummer! But, wow, 20 watts is still pretty loud, ay?
Story 2;
We had company a few nights ago. One fella, good friend and also a big metal fan and his lady. I showed him my newest acquisition (Engl Savage 120) and the Gulsekt88, as he had never heard either of them yet. Went through all the features of all four channels of the Engl, moved to the Gulsekt and showed that off a bit, and asked him if he’d like a crack at it.
Sure! Ok, cool, what do you want to plug into? “That one, it just sounds better.” That one? Was the Gulsekt88. Probably about a $200 investment so far, beat out a $2,000 big league amp. I did not expect that at all, and wasn’t staged in the least. Just a couple buddies havin fun with toys, hanging out.
Wow.
I’ve got a feeling this Ghetto-UL thing is gonna catch on!
-
statorvane
- Posts: 568
- Joined: Thu May 11, 2006 3:28 pm
- Location: Upstate New York
Re: Gulsekt-88!
Pretty good demo. That was "Black Diamond" in there right?
Re: Gulsekt-88!
You have a 666 ohm resistor for the PI cathode! No wonder the cops came a knocking.
What?
Re: Gulsekt-88!
(deleted)
Last edited by matt h on Fri Mar 27, 2015 4:40 pm, edited 1 time in total.
Re: Gulsekt-88!
Thanks statorvane! Yep, Black Diamond indeed. That's the "old" demo now, all the stuff in that big list has been done since then.
Jana, yours don't?... Haha! Matt gave me a range of R's and told me the response I could expect, and I went right in the middle. If it's any consolation, the closest Mouser has is 665.
Guess it just adds to that "on the brink" sound.
Needless to say I'm very happy with this amp!
Jana, yours don't?... Haha! Matt gave me a range of R's and told me the response I could expect, and I went right in the middle. If it's any consolation, the closest Mouser has is 665.
Guess it just adds to that "on the brink" sound.Needless to say I'm very happy with this amp!
-
EtherealWidow
- Posts: 333
- Joined: Sun Jun 10, 2012 8:47 pm
Re: Gulsekt-88!
Really looking forward to hearing the updated clips of this amp. Very funky topology all around so far. I like it!
Re: Gulsekt-88!
Hey all,
I finally switched over to Orange Drops, but not before I made recordings for comparative research purposes. (Like it hasn't been done before, or something...) The song I selected to riff out is a fun one by a band I like, and displays what this amp was designed to do, heavy.
It probably took more time to record, edit, and make this video than it did physically removing and replacing all 11 of these caps... So, last time I do something like this!
Caps A and Caps B... Which is which? (Polypropylene & Polyester Vs. Orange Drops. - Spoiler; the difference is very slim.)
https://www.youtube.com/watch?v=QVB6lVoGuKg
While I have your attention, whom might I get in touch with to make a super simple head cabinet for the final build? Bottom, sides and top, the visible kind of dovetail, (Technical term, right?) nothing fancy or too involved, not even finished. Please PM me, I'm ready to make an order!
I finally switched over to Orange Drops, but not before I made recordings for comparative research purposes. (Like it hasn't been done before, or something...) The song I selected to riff out is a fun one by a band I like, and displays what this amp was designed to do, heavy.
It probably took more time to record, edit, and make this video than it did physically removing and replacing all 11 of these caps... So, last time I do something like this!
Caps A and Caps B... Which is which? (Polypropylene & Polyester Vs. Orange Drops. - Spoiler; the difference is very slim.)
https://www.youtube.com/watch?v=QVB6lVoGuKg
While I have your attention, whom might I get in touch with to make a super simple head cabinet for the final build? Bottom, sides and top, the visible kind of dovetail, (Technical term, right?) nothing fancy or too involved, not even finished. Please PM me, I'm ready to make an order!
Last edited by Meat&Beer on Sat Mar 22, 2014 7:15 am, edited 1 time in total.