Based on 7 or 8 hours of tweaking and experimentation with the DirtBag, plus partially tracing out the Memory Boy here are the suggested alternative values I've selected. These seem to be the best values possible for minimizing distortion while keeping the delay line levels high enough and not too grainy. It's not perfect, but I feel confident now that it's as good as it's going to get without some radical alteration in design. Which would not be a bad thing, but it also would not be a Memory Man either!
Anyway, here is what you need to change:
R62 - 15k from 7k5
R42 - 20k from 11k (value is not critical--22k is fine)
R17 - omit/remove
R16 - jumper instead of 33k
C9 - 10uF from 4u7
R11/R12 - 47k --- 24k resulted in more distortion with the other changes listed so use 47k for both. This results in an output voltage of just over 6v, which is the case with the Memory Boy.
R10 - a combination of 1uF and 6k8 in series instead of a single 68k resistor. I suggest using either multi-layer ceramic or electrolytic here. If using electrolytic then make the positive end go toward C7 and the negative end toward the 6k8. The addition of the cap makes a big difference in keeping the repeats more even and longer lasting.
A possible mod: you can lower the value of that 1uF from above to filter the repeats, if you like. Anything from 15n to 33n will give you a noticeable "telephone" type filter, which I think sounds really cool (similar to the Deep Blue Delay). For experimenting, I used a socket for R10 and then ran wires from the two ends to the breadboard, then just swapped out different caps to see what worked. 1uF has the least amount of coloring, and 33n is very effected.
All other values are stock. These mods would be done INSTEAD of the earlier mod I suggested (replacing R21 and C14 with 100k resistors).
Overall, this improves the delay significantly, but it's not perfect. The threshold and release of the compressor is just not great and I have not found any way around that. But, with very careful (and minute) tweaking of GAIN1 and GAIN2 you can get very acceptable results. There will still be some hiss with very soft notes and long delay times. As I stated in the other thread this is exactly the case in the Memory Boy.
So, I hope this is somewhat more satisfactory of an end result for everyone. I wish it were perfect, but I feel like it's as good as it can be with these changes. One positive note: the delay from the DirtBag seems to be about 100-200ms longer than the Memory Boy!
Thanks Madbean for putting so much time in this.
Much appriciated.
RonaldB
Thanks Bean!
Thanks for this.
Feel almost like I'd be better starting another one though. I'll ply mine some more and have a think.
There's a large number of parts to desolder.
I just finished doing all of the mods listed here (the ones in gold). I also removed all of the circuitry related to the overload led. I think it is pretty close to where it needs to be. I may send it off to my brother-in-law so he can bias it with a scope. Removing the overload led circuitry seemed to help reduce the distortion. Anyway I am ready to box this up and just tweak the trimmers.
Quote from: mjcyates on December 21, 2011, 10:05:13 AM
I just finished doing all of the mods listed here (the ones in gold). I also removed all of the circuitry related to the overload led.
would that be everything located above c12 on the schematic? or are any of those parts critical?
R18, 19 and 20, C13, Q1 and D1. You can omit those if you don't want the overload LED. They have nothing to do with the delay---just a visual indicator of the line level into the BBDs.
To be honest, this is a lot of changes, and the build PDF still seems to not have been updated.
I'm getting quite concnered that with the amount of desoldering I'm going to have to attempt on a very tight board that I'm going to end up with a non working delay, which will be very annoying considering the initial outlay and the time spent building it this far. I really would have expected that both the v3205 and 3005 versions would have been built and tested on the production boards before this was made public - that's surely the bare minimum level of testing for a multi use board?
I certainly didn't start building this project (or purchase the board) thinking it hadn't been verified as working, and the build document didn't suggest this either, indicating that only two component subs and some jumper changes were needed to convert for use with the Cool Audio chips.
At this point I really wish I had a fresh board to work on, but as it is all my caps and most of my resistors (including all but one of the above changes) have been soldered in place. It's going to be a lot of work to attempt to make these modifications and I'm pretty disappointed I have to do so.
Having said that I appreciate that Brian has investigated the issues and tried to put it right, but I do feel let down this was not tested before the boards went on sale. I have outlayed significant monies on the board mounted pots, and chips from Small Bear along with the board itself. I just hope I can get something workable out of it.
I understand your concern, however it is not as daunting as it may seem. If you go slow, make sure you mark the components your are replacing with a sharpie, and have a little patience you will be successful. I did all of the changes yesterday in about 45 minutes using desoldering braid from Radio Shack.
Quote from: mjcyates on December 22, 2011, 06:27:30 AM
I understand your concern, however it is not as daunting as it may seem. If you go slow, make sure you mark the components your are replacing with a sharpie, and have a little patience you will be successful. I did all of the changes yesterday in about 45 minutes using desoldering braid from Radio Shack.
I used desoldering braid on the previous components I have already socketed (R21 and C14, which now are to be reverted to their stock values.. ) and didn't manage to get the 2 sided via completely free of solder for any of the joints, it involved inserting the socket whilst reheating what remained - which is not a simple process.
Mike, I'm sorry to hear you're disappointed, but I understand it.
If I can help you understand at all, Brian did build several prototypes of this and other boards, but he has admitted that perhaps the proofing was a little rushed. His builds went together well and quickly, so there was no expected problems to be had. Once several builds experienced issues he looked into it further and found the issues.
Is there a way I can help? I have trouble desoldering the double sided boards as well, but I recently got a desoldering bulb to use for desoldering and that seems to work much better than the braid I've typically used. Perhaps finding a better tool to use would be worth looking into? I bought that desoldering bulb for 5 bucks I think.
Jacob
Quote from: jkokura on December 22, 2011, 07:33:19 AMBrian did build several prototypes of this and other boards, but he has admitted that perhaps the proofing was a little rushed. His builds went together well and quickly, so there was no expected problems to be had.
I don't understand.
If the testing builds were made on the production boards with v3205s and the original bill of materials and experienced none of these distortion issues, then why are we being told to make these changes?
I might have to look into buying some more desoldering apparatus if I run into difficulty getting these components out, and I'll cross that bridge when I come to it.
Thanks, Brian!! I'll be populating my DirtBag sometime this week, and your thorough efforts are greatly appreciated.
Mike, I am empathetic to your concerns, and I understand that it is frustrating to re-do work. But, to suggest that I somehow did not test or fully commit to making this project work is simply not true. The two different solutions I proposed here are in response to problems that SOME have encountered, but not everyone. You do not have to make all these mods. These are what I came up with after tracing and experimenting and what I feel like will give the best result for the most people. And, these are improvements compared to the results I had in prototyping the project. While I do accept responsibility for that, I'm also am realistic in the sense that different people will get different results some of the time and that is unpredictable and that people also have different expectations of what the end results will be.
Just to give you some insight into what went on to develop the project...
Approximately 40 hours of PCB design. There were seven full and completely unique layouts done of the DirtBag before the final production design was finalized.
Approximately 25 hours of building six prototypes, on three different PCB designs.
At least another dozen hours of picking apart many different schematic drawings of the DMM and researching topics about the DMM.
Several hundreds of dollars in prototyping PCBs and parts.
Several hundred dollars in getting the boards fabricated.
All this was done before selling the first board and took place over three to four months. To what extent I can make this process more full-proof, I don't know.
Obviously, I'm most concerned about making customers happy and not necessarily being vindicated. And, I am truly sorry for your disappointment. On the other hand, there is an underlying assumption on my part that a person who is willing to take on something as deep and complicated as the DirtBag is not going to be put off by having to do some tweaking and has the appropriate tools to do so. Maybe that is too presumptuous on my part and maybe not. Honestly, the only way to find out that sort of thing is by "breaking a few eggs" first! I do feel that I have made a pretty tremendous effort over the past week to rectify the situation, though.
In any case, I won't make excuses for myself in regards to putting something out that wasn't exactly perfect. It's actually something I strive to do every time I release a project. But, I'm realistic that projects like this don't always work out to 'paint by numbers', sometimes I make mistakes, and I cannot always be sure that everyone will be happy. I wish these things were not so, of course.
If you truly feel that you would prefer to start over rather than going through the trouble of making the changes, I will send you a new board. I'll have to do a count and see what I have left (I think I'm down to one as of yesterday--but I'll check).
Quote from: MadeByMike on December 22, 2011, 07:38:15 AM
Quote from: jkokura on December 22, 2011, 07:33:19 AMBrian did build several prototypes of this and other boards, but he has admitted that perhaps the proofing was a little rushed. His builds went together well and quickly, so there was no expected problems to be had.
I don't understand.
If the testing builds were made on the production boards with v3205s and the original bill of materials and experienced none of these distortion issues, then why are we being told to make these changes?
I might have to look into buying some more desoldering apparatus if I run into difficulty getting these components out, and I'll cross that bridge when I come to it.
Mike, it did work within the specs Brian originally thought were ok, but when other builders had issues he looked into it further and it seemed like there were issues and he just hadn't noticed or thought they were issues. He talks a little bit about it here: http://www.madbeanpedals.com/forum/index.php?topic=3336.0 (http://www.madbeanpedals.com/forum/index.php?topic=3336.0)
Jacob
*edit: Brian beat me to it I think
Quote from: MadeByMike on December 22, 2011, 07:38:15 AM
Quote from: jkokura on December 22, 2011, 07:33:19 AMBrian did build several prototypes of this and other boards, but he has admitted that perhaps the proofing was a little rushed. His builds went together well and quickly, so there was no expected problems to be had.
I don't understand.
If the testing builds were made on the production boards with v3205s and the original bill of materials and experienced none of these distortion issues, then why are we being told to make these changes?
I might have to look into buying some more desoldering apparatus if I run into difficulty getting these components out, and I'll cross that bridge when I come to it.
Mike, are you the same MadebyMike as ShortscaleMike in the U.K.?
If so if you want, if you post me your board i'l do the mods for you, i've got a good desoldering pump (which you can pick up from Bitsbox.co.uk pretty cheap) and have quite a bit of experience fighting with boards.
The problems here just came from bad luck, BBDs are ficcle beasts as is tone, it's perfectly reasonable that Bean didn't hear the issues others hear, in fact, on Freestompboxes, Dirk Hendrik said that all he did on his board was change one component to a jumper and his was fine, plus he did none of these mods on his Deluxe Memory Baby either, all in the ears of the particular person and what they find acceptable.
And testing probably was a bit rushed yeah, but us (the collective DIY) are probably to blame for that for being an impatient bunch ;)
Edit: Just read Beans post, testing was most definitley NOT rushed, i'm amazed!
Don't ever stop what you're doing Brian :) this work is greatly appreciated.
Certainly I have laughed a lot at the incessant begging of projects to be released a few times!
We all have a pile of circuits on our desks that are either not working and need to be fixed, or are not working and will probably never see the light of day! This is one that you CAN get working though.
Jacob
Anyone in Manchester handy with a desoldering method? ::) :)
Ive kinda given up and just accepted mine as it is.
In the future I might build another one if the boards get restocked.
Quote from: jkokura on December 22, 2011, 07:59:20 AM
Certainly I have laughed a lot at the incessant begging of projects to be released a few times!
Jacob
I guess I wasn't a part of that pressure, I just heard about the project from someone ordering a PCB and posting about it on HCFX, and ordered it from the madbean website along with the CurrentLover, which also excites and impresses me as a project. I've ordered from Brian a few times before this and been nothing but impressed, plus I've used his schematics as reference for veroboard layouts also - this has all contributed to the fact I was under the impression this was a solid 100% tested and verifed BOM and would all go together smoothly.
Thanks for your detailed reply Brian, I really do appreciate it - as I do the offer of a replacement board. I may take you up on that and build the newly recommended BOM from the start on that, but I think I owe it to you to attempt to make the changes you've recommended to my current board first. If and only if I fail to get a working solution would I consider it fair to ask for a replacement board.
I understand this is complex and a demanding build, but I'm not sure that I accept someone willing to take it on should also be expected to desolder components that were not misplaced - I'm sure noone enjoys doing this on an expensive 2-sided board. They're lovely to solder into - desoldering and clearing pads not so much.
I guess most of the frustration and confusion is coming from the fact that there's people like Dirk who built his and with one component jumpering is fine, and then a bunch of guys here who had unworkable distortion and had to make a bunch of mods to get things in line - and still at this point we're being told that either we could be 100% satisifed by
1) the original BOM
2) the original BOM with the 100k x2 switch
3) the original BOM with the changes mentioned in this thread applied.
You have to admit that is a lot of different options and as someone who's wanting to limit the amount of tricky unsoldering it is a bit overwhelming.
I'm particularly not looking forwards to changing R10 and R42 in particular.
I'll do my best and let you know if I end up experiencing unrecoverable trouble.
Thanks
Mike
Quote from: Scruffie on December 22, 2011, 07:56:07 AM
Quote from: MadeByMike on December 22, 2011, 07:38:15 AM
Quote from: jkokura on December 22, 2011, 07:33:19 AMBrian did build several prototypes of this and other boards, but he has admitted that perhaps the proofing was a little rushed. His builds went together well and quickly, so there was no expected problems to be had.
I don't understand.
If the testing builds were made on the production boards with v3205s and the original bill of materials and experienced none of these distortion issues, then why are we being told to make these changes?
I might have to look into buying some more desoldering apparatus if I run into difficulty getting these components out, and I'll cross that bridge when I come to it.
Mike, are you the same MadebyMike as ShortscaleMike in the U.K.?
If so if you want, if you post me your board i'l do the mods for you, i've got a good desoldering pump (which you can pick up from Bitsbox.co.uk pretty cheap) and have quite a bit of experience fighting with boards.
Thanks for the offer, but I'll do my best to sort it myself. When I realised I would have to start desoldering things I went hunting for a pump on bitsbox (I love those guys) but foudn it's sold out unfortunately, or I would have got one:
http://www.bitsbox.co.uk/tools.html
I don't want anyone to think I am overly criticising Brian here (and your comment about him carrying on doing what he does, of course that is the last thing on my mind - he is doing a great service to many effects lovers and that is to be applauded completely).
I remain a big fan of madbean pedals.
Mike, I hear you. And, I'll keep your feedback in mind going forward. Of course, I will always strive to make MBP the best it can be and have satisfied customers...that is the most important thing to me.
Quote from: jkokura on December 22, 2011, 07:59:20 AM
Certainly I have laughed a lot at the incessant begging of projects to be released a few times!
Haha, I think i'm at least a tad guilty of doing it my self, although I can still laugh at it on occasion...
Quote from: LaceSensor on December 22, 2011, 08:02:36 AM
Anyone in Manchester handy with a desoldering method? ::) :)
Ive kinda given up and just accepted mine as it is.
In the future I might build another one if the boards get restocked.
Are you using a Pump? It really should be as simple as desoldering the bottom of the pad and then desoldering from the top of the pad, if you want you can post me yours, i'm not in Manchester though.
Quote from: MadeByMike on December 22, 2011, 08:09:22 AM
Quote from: jkokura on December 22, 2011, 07:59:20 AM
Certainly I have laughed a lot at the incessant begging of projects to be released a few times!
Jacob
I guess I wasn't a part of that pressure, I just heard about the project from someone ordering a PCB and posting about it on HCFX, and ordered it from the madbean website along with the CurrentLover, which also excites and impresses me as a project. I've ordered from Brian a few times before this and been nothing but impressed, plus I've used his schematics as reference for veroboard layouts also - this has all contributed to the fact I was under the impression this was a solid 100% tested and verifed BOM and would all go together smoothly.
Thanks for your detailed reply Brian, I really do appreciate it - as I do the offer of a replacement board. I may take you up on that and build the newly recommended BOM from the start on that, but I think I owe it to you to attempt to make the changes you've recommended to my current board first. If and only if I fail to get a working solution would I consider it fair to ask for a replacement board.
I understand this is complex and a demanding build, but I'm not sure that I accept someone willing to take it on should also be expected to desolder components that were not misplaced - I'm sure noone enjoys doing this on an expensive 2-sided board. They're lovely to solder into - desoldering and clearing pads not so much.
I guess most of the frustration and confusion is coming from the fact that there's people like Dirk who built his and with one component jumpering is fine, and then a bunch of guys here who had unworkable distortion and had to make a bunch of mods to get things in line - and still at this point we're being told that either we could be 100% satisifed by
1) the original BOM
2) the original BOM with the 100k x2 switch
3) the original BOM with the changes mentioned in this thread applied.
You have to admit that is a lot of different options and as someone who's wanting to limit the amount of tricky unsoldering it is a bit overwhelming.
I'm particularly not looking forwards to changing R10 and R42 in particular.
I'll do my best and let you know if I end up experiencing unrecoverable trouble.
Thanks
Mike
To be honest, we should be glad that someone has even attempted a project like this that allows people to build an effect with in production BBDs rather than a select few being able to.
There's a warning in the Project files saying this wouldn't necessarily be easy and that it could lead to the loss of time and money, something that should definitley be taken to heart.
These types of projects are always going to be a risk for someone providing them and I can't thank Brian enough for stepping out of the comfort zone to bring them, the current output has had some really exciting stuff in it and i'll happily accept a few issues along the way if it means we keep getting this type of project, i'd hate for him to be put off by a few kinks in the road and to just stick to standard effects.
As with any build though, it really should be breadboarded first, yes it's huge, but that's all the more reason to, this is not a simple build, it has a lot of chance to not be right the first time for everyone.
Hell, a lot of people complained about the EHX versions of the 3208 memory man! And they're an entire company, not just one man.
Quote from: MadeByMike on December 22, 2011, 08:19:47 AM
Quote from: Scruffie on December 22, 2011, 07:56:07 AM
Quote from: MadeByMike on December 22, 2011, 07:38:15 AM
Quote from: jkokura on December 22, 2011, 07:33:19 AMBrian did build several prototypes of this and other boards, but he has admitted that perhaps the proofing was a little rushed. His builds went together well and quickly, so there was no expected problems to be had.
I don't understand.
If the testing builds were made on the production boards with v3205s and the original bill of materials and experienced none of these distortion issues, then why are we being told to make these changes?
I might have to look into buying some more desoldering apparatus if I run into difficulty getting these components out, and I'll cross that bridge when I come to it.
Mike, are you the same MadebyMike as ShortscaleMike in the U.K.?
If so if you want, if you post me your board i'l do the mods for you, i've got a good desoldering pump (which you can pick up from Bitsbox.co.uk pretty cheap) and have quite a bit of experience fighting with boards.
Thanks for the offer, but I'll do my best to sort it myself. When I realised I would have to start desoldering things I went hunting for a pump on bitsbox (I love those guys) but foudn it's sold out unfortunately, or I would have got one:
http://www.bitsbox.co.uk/tools.html
I don't want anyone to think I am overly criticising Brian here (and your comment about him carrying on doing what he does, of course that is the last thing on my mind - he is doing a great service to many effects lovers and that is to be applauded completely).
I remain a big fan of madbean pedals.
Yeah bitsbox are a handy source in the U.K. i've been a customer since I started doing DIY and still get all my Enclosures from them.
My comments about Brian carrying on aren't aimed at you, they're more just to thank Brian for his work and to not let issues like this make him think twice in the future about complicated effects because of the risks with them, I definitley understand that you're dissapointed but I also understand it's easy to get in to a build like this and not get what you wanted first try.
FYI: I would rather make things comfortable enough for someone to feel they can express disappointment as long as it's honest because I see that as an opportunity to improve MBP. So, I don't take things personally and certainly everything Mike and a couple others have expressed is "in bounds". Now worries there. I do truly appreciate thanks and praise, too, but I'm humble enough to want to continue to earn that.
QuoteI do truly appreciate thanks and praise, too, but I'm humble enough to want to continue to earn that.
You are earning it in my book. Thanks!
Good news, folks! (http://www.madbeanpedals.com/forum/index.php?topic=3380.0)
Well said Brian, and Thank you for your hard work and outstanding effects.
Did the mods, took a while but the delays are beautifull right now.
Thanks. Madbean and Scruffie
ROnaldB
has anyone (especially those that experience difficulties) ever attempted to do a comparison to a real DMM?
madbean, have you talked to Dirk_Hendrik about the change he made (only a jumper?).
maybe it would help to send a few audiofiles back and forth to compare whether something "is normal that way, the original does it too" or "wow shit, that's actually really bad".
I mean if Dirk does it with a jumper and is satisfied and LaceSensor isn't even with the new mods there is certainly either a discrepancy in expectations (no offense) or something with the biasing didn't go right on LaceSensor's build. Hell, maybe there's even an accidentially wrong component somewhere on your build Lace, though I fully assume you have checked all the resistor bands and cap values before posting a complaint.
To be honest, I'm a little anxious now, but will probably stick with building it with v3205, as buying MN3005s is still much more expensive than redoing the v3205 if i run into difficulties. RonaldB gives me much hope :)
I'm very sure I didn't make a mistake. I listed my changes, which were few and minor.
As I said I'm 95% happy and I will do the mods at some point when I can feel confident in not ruining it completely.
ah you didn't do the new mods, sorry about that.
hope it works out for you! :)
hi,
can i use this kind of trimmer for the dirtbag??
http://www.banzaimusic.com/horizontal-c-575/
thanks!
It doesn't look like it has the right kind of pin spacing. Better to go with Bourns.
Jacob
I have did the mods last week but they didn't come out as suspected.
I still have some distortion on my echos and i have to hit my strings very hard to get echos happening.
Also i here the LFO sweep in my echos.
So what could be done here?
RonaldB
EDIT: I found the problem bad solder joint. Works fine now.
sounds like you made a mistake somewhere else.
edit: told ya :D finally got my board (christmas at usps). Can't wait to stuff it!
Quote from: ramengo on December 27, 2011, 12:35:25 PM
hi,
can i use this kind of trimmer for the dirtbag??
http://www.banzaimusic.com/horizontal-c-575/
thanks!
i use these usually, i just move and bend the legs a bit
http://www.banzaimusic.com/horizontal-c-399/
Guys - quick question:
I'm about to start a v3205 build, and would prefer to save myself as much debugging time as possible. I socketed R21 and C14 in case I need to go that route. My question:
Would it be better for me to build it based on the stock BOM and hope for the best, or just go straight to the changes in this thread?
I recommend doing the changes outlined here. It will produce a superior result. It's only a matter of some different values and one added component, so I think it will give you the least amount of headache.
Which reminds me I need to put this info in the doc, too.
At some point I'll break this one out again and tinker with it, but as is with the mods outlined here result in less distortion and a better sounding delay.
Congratulations for your work Brian.
I´ve finally made my dirtybag work. But I notice an issue. The signal that pass through (not the delayed), gets overdrived. The pedal works like a booster. I have to put the level pot at minimun (10%) to have a clean signal. I imagine that this is not usual.
All the rest works perfect, even the modulation. I built the stock version, but when finished, I discovered this thread and performed the (R62-R42-R17-R16....) mod, And I noticed the better sound of the delayed signal. R11 and R12 are 47k, and R21 is 1k and c14 33nF as stock version.
My voltages at IC1 are:
pin1 - 4.53v
pin2 - 4.53v
pin3 - 4.30v
pin4 - 0v
pin5 - 4.12v
pin6 - 4.53v
pin7 - 4.53v
pin8 - 9.11v
I assume that the problem has to be in IC1, any idea?
thanks crew
I may had had a similar issue. Check that video & thread:
http://www.madbeanpedals.com/forum/index.php?topic=3701.msg32963#msg32963
That's the design of the DMM....it's the basic function of the Level pot to act as a boost when turned up. If you don't want all the boost you can lower the value of the pot. 250k or 500k audio would be good choices. Or, just leave it turned down.
Yes, I can confirm my EHX DMM does exactly this. I've come to love the extra dirt and tone coloration though, I was sad when I could not get Memory Boy to do the same thing. My EHX DMM is always having gremlin type issues so I'm slowly building Dirtbag hopefully as a road worthy replacement and I can retire the original to studio use only
Strategy
Quote from: madbean on February 27, 2012, 06:06:33 PM
That's the design of the DMM....it's the basic function of the Level pot to act as a boost when turned up. If you don't want all the boost you can lower the value of the pot. 250k or 500k audio would be good choices. Or, just leave it turned down.
Ok, thankyou very much folks!!
I´ve changed my mind. I´m going to leave the effect as it is. As you said Brian, I only have to adjust the level pot to choose the sound I want. Thanks again, for your hard work developing and tuning this wonderful project.
I encourage everybody to perform the (R10,R17...) mod. No Fear. It´s a thick 2 sides PCB, but if you take a little care and work with no rush, for sure you´ll be succesfull.
It's actually a nice dirty boost. In the vintage version, it wasn't true bypass so you could use it to boost your clean signal, then kick in the delay when you wanted.
Yo
Update. Got round to building up my replacement board, seems to work ok with the mods suggested.
I need to keep tweaking the Bias and Gain trims around, but its working for sure.
I did the blend mod too. Works as advertised.
Fun 4 hours of my evening that was.
Quote from: LaceSensor on March 05, 2012, 04:06:09 PM
Yo
Update. Got round to building up my replacement board, seems to work ok with the mods suggested.
I need to keep tweaking the Bias and Gain trims around, but its working for sure.
I did the blend mod too. Works as advertised.
Fun 4 hours of my evening that was.
Simply cannot get this to bias properly, or sound even close to decent.
I wonder if I have made a mistake.
I took my intial "phew its working" after hearing repeats, figured I just needed to revisit it and tweak a bit, seeing as the basics were there, so left it for a few days.
Come back to it and honestly I would say the results arent even close to what I had with the previous build. When I get the patience I will come back with voltages etc, for now I just wanted to post this up.
Im using all the same parts (in terms of the actual ICs) to my first build, along with all the mods listed.
Have you recorded any samples of your results, Lace? I'm really curious to hear what you have to compare.
Quote from: madbean on March 12, 2012, 07:19:28 AM
Have you recorded any samples of your results, Lace? I'm really curious to hear what you have to compare.
ill try to find time this week.
Im at a loss as I am pretty sure I built it right.
The old one went to Scruffie to have a play with after it was a bit butchered from desoldering.
Really I can say that the old one, before I butchered it, sounded better than what I have here now.
I think maybe this project is just my nemesis.
I know they aint quite so fussy or complex, but ive done a number of what people consider "harder" projects such as two Aqua pusses, current lover, lowrider, 2 porkbarrels I really think I am capable just this one doesnt love me one bit :P
Thanks
LS