Phil Starr

The simplest thing would be to buy a DI box that would take an input from the speaker output on your amp. It would be a high impedance so would not affect the impedance the amp is 'seeing' but you should run it in parallel to a speaker as valve amps don't like high impedance on their own. You can then feed from the DI box to the slave amp. Just to be clear because you don't want anything to break. Plug your speaker into one of the sockets on the back of the DR103 then another lead into the second socket on the amp and run it to the DI box then a lead from the DI out to the slave amp. Check the DI box is switched to 'speaker' before switching the amp on. Check both amps are turned down before switchng on. Set your level on the 103 then turn the slave up to match that level. using this system should mean the eq you apply to the amp is reproduced in the slave. Something like this will do the job but there are lots of choices Studiospares Passive DI Box - Studiospares Alternatively you could play in stereo and split the signal before the amps but you will need either some sort of mixer or splitter between the bass and the amps.

Intermittent faults are the worst This above is what you have to do. You also have to clear your head of preconceptions. In this situation you just can't trust anything including all the checks you have already done and the idea that this is a single fault. There may well be more than one component faulty and they may be interacting with each other, or not. I can't tell you how many times I've gone through this to find it was something I checked right at the beginning or a brand new component I'd replaced and just assumed was good. It's probably worthwhile keeping a note of the combinations you try and what happens. Just one other thought the zoom G1 has a headphone output. if you put it in the middle of your chain you could check whether the fault was before or after the G1. good luck

Hi Tom, looks like the Phantom power is a bit of a red herring, the problem of describing someone else's fault remotely. if you read the AC instruction above you can see that as it is a dynamic mic you don't need phantom power. For a working SM58 it doesn't matter if it is on or off but if anything goes wrong whilst the mic is connected the phantom power might just blow the mic. safer to leave it off. If you have a working mi plug it in and get it going, then unplug the lead at the mic end and plug the new mic in it's place. If it still doesn't work then you have eliminated any lead which might have come with the new mic. remember we don't know what leads you are using. If this doesn't work and the mic doesn't work in another system then it's the mic. There are two possibilities in the mic, sometimes a lead has broken inside, there will be two running from the socket at the bottom of the mic up to the capsule the working part of the mic or the capsule itself needs replacing loads listed on eBay but make sure you get a genuine one. If you can't solder then you'll have to get someone else to have a look. Just a thought this is not a switched version of the SM58, if so suspect the switch too. In fact suspect it first

As above don't turn on the phantom power but if you have to to provide power for another mic then check your mic lead is wired correctly. If it is the mic should be protected from the phantom power but any mistakes in wiring your leads could cause the voltage to be applied across the mic coil. Also any sort of short even a temporary one can damage your mic so it is best to plug in leads before switching on the power and keep the volume turned down.

I was really impressed with the video editing. Looking forward to hearing what the ports do to the sound.

Funny you should ask. I've just bought an INuke DSP amp from @Kevsy71 to investigate just that. The DSP gives you a wide range of options about crossover frequency roll off, delay and so on as well as compression/limiting to protect the drivers. If it is successful it might be a good way to go active by building the amp into the cab for just over £220

That makes JackTrip look more interesting, at least you know the money is being put back into music. One of my band members suggested SonoBus SonoBus User Guide

This looks really interesting, for those who haven't clicked on the link: It's going to be a paid for service run by a not-for-profit organisation and based on work by Stanford University in the States. The prices aren't clear yet. Basically they are cutting the latency with an external box which cuts the latency to 1mS and replaces your sound card. Then there will be cloudhosting managing the connections. There are a few other tweeks like adding in an unbalanced connector for your mic and wiring everything direct. The boxes aren't available yet but will be managed by a Raspberry Pi and another board. you can buy a kit of parts from Amazon but they only have 16 sets. Looks like you can buy the kit for £150-200 or use their information to build your own. You'll also have to pay for the stuff they are doing in the cloud. There are so many details on their site I may have missed something.

Question about interfaces, I notice that Behringer (and presumably everyone else) do a 2 way interface which is £37 and one which is £59. 16bit 24kHz and 24bit 192kHz. obviously the quality is going to be better with the faster sampling rate but latency? Secondly a lot of small mixers have USB outputs including one I have here. Will they work as well or again is latency going to be more of a problem?

I'm very analogue I'm afraid

Just looked at JamKazam it's got to be worth a try, and there's a free version, with restrictions but at least a way of trying it. Not yet 9.00 and I've learned something new

In terms of rehearsing together I don't think any of the platforms are going to work because of the time delay (latency). Even a few thousandths of a second sounds weird but coincidentally we were experimenting on Zoom two nights ago. Trying a few songs and sharing screens, the time delay on Dakota was 2 beats or about 1 sec. I'm sure faster connections and better hardware could reduce that but there's no way you are ever going to be able to lock in with other band members. I think the only thing you can really hope for is recording your parts separately and sending the files across to play along with. I'm hoping there is something I've missed and that there are ideas of things that can make practice more interesting and stimulating and I'll follow the thread but I'm not hoping for much

Not too worried about the resale but wondering about how much work is needed. It's been stored for years and they don't even have an amp so it means going up with an amp and two 9V batteries I now know. Plus my other half will kill me You are tempting me though, sounds good too on the You tube review I found and yes Japanese Matsumoku 1985.

Thanks @Happy Jack, I'm not sure about this one it's been knocked about and one of the controls is broken and it's a little way away. I'm hoping someone will see this and say what it's worth. Nowadays I only remember the distant past

@Happy Jack did you ever get to play this bass? I've just seen one going cheap which needs some tlc. Basically I want to ask all the questions you asked all those years ago basically is it worth some time and money. What would be a good price now?

Good luck with the recovery, there will come a time when a nice relaxing project will be just the thing . You might find it fun to do some internet research whilst you are laid up. I've designed stuff for someone in Australia before and sourcing drive units was an issue. A lot of the stuff available here wasn't available over there at the time and the exchange rate was appalling. That's bound to have changed in the last ten years but we did find an Australian manufacturer and some lovely drivers.

I quite like carpet felt but it is heavy. You'll find most pillows and Duvets are packed with polyester wadding which is also sold for speakers. Don't let it cover the ports.

Oh forgot to say the only 4cm tube I have to hand is the liner of a toilet roll, I'm sure you have them at home ? if not you might find a round shampoo bottle the right size. Cardboard is quite a good material for a port if it is thick enough. you can stiffen it up with papier mache, (soak newspaper in watered down glue and wrap it round the outside).

OK I'd go for two tubes 6.5cm long which will give you a little bass lift at 120 Hz. Not real bass but it will make things sound just a touch punchier/warmer. That speaker actually models just a little better in your cab than mine

I do like a happy ending, and yes good video too. If you measure up the inside of the cab and the diameter of those holes I'm happy to do the calculations for you, I may even have some port tubing the right size I can post. Hope you feel better soon.

Now corrected I meant to refer the excursion, I got called away halfway through posting, sorry

You've got your advice and I think you realised this anyway from the way you asked the question. Yes you can damage your speakers with an amp even within the specified power rating of the speakers and the enemy is extreme equalisation/fx. There are two ways to break a speaker and they are interrelated. you can do it one way or the other or a little of both. The enemies are overheating the coil and moving the coil and cone past their mechanical limits. The graph below shows the movement of the cone of the same speaker with the red plot at 1/4 of the power of the green plot. You can see tht the excursin rises as the frequency goes down but at 50 Hz the port takes over and the cone movement reduces right down. The horizontal red line is the excursion limit of 6.5mm. You can see that at full power the cab goes outside it's limits between 55 and 90Hz and again below 45Hz. If you put a bottom E at full power with an octaver (41Hz/2 or 20Hz) it would force the cone to travel through a 6cm round trip which would hammer it against the back of the magnet 20 times a second. Not good. So for these frequencies (where the curve goes above the red line) the power handling is limited by the excursion. For the rest of the time the limit is the thermal limit. So there you are the power to any speaker is less than the rated thermal limit at certain frequencies, genrally lower frequencies but there's almost always that dip just above the port frequency too. If you use just 3db of bass boost you will halve the power handling and an octaver is even worse. A decent HPF will pretty much help any reflex(ported) speaker cab by removing that huge spike in excursion below the tuning point.

you've heard my bass playing, I'm saying nothing

I didn't save the data so this is from memory, which may of course be faulty. I agree with you about the potential 'better' performance from the red speaker. That's certainly a cleaner curve and showing 'better' damping of the hi-fi driver. Resonant frequency is lower as you would expect with a slightly heavier cone and a less stiff suspension. The sensitivity was very similar if I remember correctly, at the expense of lower excursion limits. I've met PeaTurgh and he says in this thread some of this stuff goes beyond him so I made the assumption what he wanted was a practical solution and a fun project rather than an extensive breakdown of options. I was concerned about the excessive excursion below 50Hz but wanted to show him the frequency plots so he could see the gains the hi-fi drive potentially offered for himself and ask about that if he wanted to and all of this is there in what I've said. I must admit I had reservations about recommending a £12 speaker with potential reliability issues against a speaker I had actually in a similar cab in my room in front of me. I pm'd him with a recording of my bass through the cab to see if he was happy with the sound I was getting. I'd deliberately tailored the response of my own cab and it wouldn't necessarily suit him. So yes, this was a recommendation based upon practicality. I quite like my little practice amp. the lack of bass means it doesn't annoy my neighbours, the 2db hump at 120hz gives it a gentle suggestion of bass and it sounds OK just plugged and played. Above that it's nice and clean, revealing enough to show up my every mistake which is what I need for practice. Unlike the cheap beginners amp it started out as it now sounds like a bass. The Monacor speaker would probably have sounded great with noticeable extra bass and probably survived quiet practice but i couldn't really recommend something that I thought might not be reliable long term.

I think the tweeter as an upgrade for the Mk1 would be a great idea. It would keep the concept of an easy build but get very close to the performance of the Mk2. I need to redesign the proportions of the Mk1 as it was proportioned to match the old 19" class AB amps people were still using then. It will be a simple job to leave space for a horn unit to be added later. If you could add a horn for between £50-100 I think people would go for it. Building a Mk1 with a horn would effectively reinstate the Mk2 as an affordable two way design with the Mk3 with the Neo/lightweight/top quality tweeter as the state of the art cab.