Which Ampeg B15 ... to build?

[JapanAxe]

@agedhorse - to be fair, @Hellzero does mention a resistor for discharging caps.

[Hellzero]

Thanks @JapanAxe. I was about to answer and the LED is there so you can see that the capacitor is fully discharged.

In a tube amp, the tensions are the most important, so with a multimeter and a capacitance meter (or an ESR that can manage high capacitance values and tensions) you can repair any amp. You have to know two things : how the tension flows and how the signal flows.

That said if the amp is blowing fuses, I don't think a scope will be of any use... And if you use a scope, you'll need a signal generator too...

[Hellzero]

The LED is in series with the resistor, of course. 😉

[agedhorse]

8 hours ago, Hellzero said:

Thanks @JapanAxe. I was about to answer and the LED is there so you can see that the capacitor is fully discharged.

In a tube amp, the tensions are the most important, so with a multimeter and a capacitance meter (or an ESR that can manage high capacitance values and tensions) you can repair any amp. You have to know two things : how the tension flows and how the signal flows.

That said if the amp is blowing fuses, I don't think a scope will be of any use... And if you use a scope, you'll need a signal generator too...

How are the voltage (tension) the most important? There are many important aspects to the signal path of an amp, and while the voltage is ONE part of this, there are many other important factors in identifying not only where the fault might be located, but also what the fault might be.

"Tension" (voltage) doesn't flow, it is a potential. CURRENT flows.

Perhaps there is a challenge here with language?

[agedhorse]

8 hours ago, JapanAxe said:

@agedhorse - to be fair, @Hellzero does mention a resistor for discharging caps.

He mentions a resistor in series with an LED, which means that the discharge rate would be very low and the discharge time very high UNLESS there is an ADDITIONAL resistor (~10 ohm, 10-25W) like I suggested earlier.

I suspect that the communication issues here may be due to different native languages. If so, none of this is going to be very helpful.

[JapanAxe]

Still waiting for someone (anyone!) to comment on the pros and cons of the different B15 models...

[Beer of the Bass]

34 minutes ago, JapanAxe said:

Still waiting for someone (anyone!) to comment on the pros and cons of the different B15 models...

I don't have experience of the differences between the different power stages or the original amps, but I put a preamp section loosely based on the later B15n versions into an amp I modified. Personally I like a bright switch but don't find the Ampeg Ultra Lo filter useful.  I think if I were to build one for myself I'd go for the 68 B15n circuit but add the bright switch too.

[JapanAxe]

20 minutes ago, Beer of the Bass said:

I don't have experience of the differences between the different power stages or the original amps, but I put a preamp section loosely based on the later B15n versions into an amp I modified. Personally I like a bright switch but don't find the Ampeg Ultra Lo filter useful.  I think if I were to build one for myself I'd go for the 68 B15n circuit but add the bright switch too.

I'm gravitating towards the earlier preamp and the grid biased power amp. I've never found much use for the Ultra Lo filter either but some kind of bright switch could be useful. It will only take a couple of extra components to provide the cathode biased option, so I'll probably include a switch for that on the rear panel.

[Chimike]

I sense the need for a B15 shootout at the next basschat bash !

Paging Mr Beedster, I'm sure he could advise on sound, having owned one of the new reissues with the 64/66 options.

[Hellzero]

2 hours ago, agedhorse said:

Perhaps there is a challenge here with language?

 

2 hours ago, agedhorse said:

I suspect that the communication issues here may be due to different native languages. If so, none of this is going to be very helpful.

I'm always astonished to read these kind of comments that are simply insulting, but having seen your location, I fully understand your superiority complex, don't worry.

Sorry for derailing your thread @JapanAxe, but I really can't stand this stupid sectarianism.

[agedhorse]

59 minutes ago, Hellzero said:

 

I'm always astonished to read these kind of comments that are simply insulting, but having seen your location, I fully understand your superiority complex, don't worry.

Sorry for derailing your thread @JapanAxe, but I really can't stand this stupid sectarianism.

Excuse me, nothing I said was insulting nor was it intended to be.

I deal with international customers every day, I am aware that many use translation software that may not translate as accurately as assumed (either to or from anybody’s native language)

I simply suggested that this might be an explanation for the miscommunication rather than assume that you were being intentionally disrespectful.

The US is a very large country with diverse politics. Many do not find what’s going on in our country acceptable in the slightest. To assume that I (or anybody you talk with from the US) finds it acceptable is a form of casting stereotypes and may very well be wrong.

Is this how the forum thinks of all US residents? If so, if he talks for everybody here, I find it very sad.

[BassmanPaul]

On 03/01/2021 at 16:35, Hellzero said:

 

I'm always astonished to read these kind of comments that are simply insulting, but having seen your location, I fully understand your superiority complex, don't worry.

Sorry for derailing your thread @JapanAxe, but I really can't stand this stupid sectarianism.

You've just made an insinuation about someone I have known for many years. He is ALWAYS courteous  and nothing but helpful. Here in Canada we have problems once in a while between folk living in Quebec and folk living in other provinces. Translations can certainly cause difficulties until sorted. Your poor reaction is a comment on you and not on @agedhorse

As an example of his knowledge read through the thread on the Mesa TT800. He designed both it and the Subway series.

Edited January 5, 2021 by BassmanPaul

[BassmanPaul]

Getting back to the original subject of which version to build I would suggest the B15NF. It's the version I own and I love it. Mine still has the original CTS 15" driver which I preferred over the Altec and JBL 2225 I tried in the cabinet.

Using the Octal preamp tubes makes construction easier 'cos of the larger sized socket. To get the best out of the build you must use quality components. The transformers are vitally important. Cheap out here destroys your chances of good tone from the finish project. 

If you decide to use a tube rectifier: GZ34/5AR4 you should add a fast action silicon diode  in series with each plate/anode. This increases the PIV of the rectifier and curbs flashover within the tube. I had to do this with my unit for the same reason.

I wish you luck with the build and if I can be of help please ask.

Paul

[Hellzero]

2 hours ago, BassmanPaul said:

You've just made an insinuation about someone I have known for many years. He is ALWAYS courteous  and nothing but helpful. Here in Canada we have problems once in a while between folk living in Quebec and folk living in other provinces. Translations can certainly cause difficulties until sorted. Your poor reaction is a comment on you and not on @agedhorse

As an example of his knowledge read through the thread on the Mesa TT800. He designed both it and the Subway series.

What poor reaction ?

Ok, now I'm really fed up with all these insinuations about the fact I'm not fluent in English. I don't use a translator as I don't need it because I studied English, German, Dutch, Luxemburgish, Italian, Spanish, Latin and ancient Greek. It's not because my mother tongue is French that I can't be fluent in any other languages.

So, yes, I take it as an insult and I'm asking you to think twice before pretending you are the only ones able to speak English.

Ok, tension doesn't flow, it's current, but you understood clearly what I was talking about. It has nothing to do with the fact of being fluent in a foreign language, but with a technical misuse of a term that I should have corrected if I had taken the time to read back what I wrote. My fault, I admit it, but there was no need for a language crucifixion, nor unfounded allegations. Ite missa est.

[Geek99]

On 03/01/2021 at 22:42, agedhorse said:

.

Is this how the forum thinks of all US residents? If so, if he talks for everybody here, I find it very sad.

It’s not what I think at all personally; I welcome any bass player here, of any age, gender or nationality. As long as you’re not a fricking guitarist ... 🤮

[Geek99]

34 minutes ago, Hellzero said:

What poor reaction ?

Ok, now I'm really fed up with all these insinuations about the fact I'm not fluent in English. I don't use a translator as I don't need it because I studied English, German, Dutch, Luxemburgish, Italian, Spanish, Latin and ancient Greek. It's not because my mother tongue is French that I can't be fluent in any other languages.

So, yes, I take it as an insult and I'm asking you to think twice before pretending you are the only ones able to speak English.

Ok, tension doesn't flow, it's current, but you understood clearly what I was talking about. It has nothing to do with the fact of being fluent in a foreign language, but with a technical misuse of a term that I should have corrected if I had taken the time to read back what I wrote. My fault, I admit it, but there was no need for a language crucifixion, nor unfounded allegations. Ite missa est.

Your English is fine

[agedhorse]

5 hours ago, Geek99 said:

Your English is fine

Yes, it appears not to be a language misunderstanding, just showing his true personality. 

Edited January 6, 2021 by agedhorse

[Geek99]

5 hours ago, agedhorse said:

Yes, it appears not to be a language misunderstanding, just showing his true personality. 

I didn’t even realise @Hellzero wasn’t speaking a mother tongue and I speak three languages with odd bits of others too. 

Edited January 6, 2021 by Geek99

[Steve Browning]

I would respectfully suggest that agedhorse is being a technician here. In my day job I am exactly the same. It's vital to be 100% accurate and I will always correct people when they refer to something zero rated for VAT as being exempt. To the layman they may seem the same but they are radically different.

I am reading a techician ensuring he has full understanding of what is happening and making sure that every aspect is covered. Frankly, that is providing the benefit of proven knowledge and experience.

[Hellzero]

So, now that everything is clear, should we get back on track and give the answers @JapanAxe is waiting for : comments about early Ampeg B15's and their different tonal characteristics.

😊

[Steve Browning]

Personally, I would throw the Heritage B15 into the mix. I used one as the house bass amp at a studio a couple of years ago and it sounded lovely (I used to own a 70s B15) and has the advantage of that extra power.

[BassmanPaul]

Personally the only Latin I learned was Pig Latin!!

 

 

[BassmanPaul]

22 hours ago, Hellzero said:

Ok, tension doesn't flow, it's current, but you understood clearly what I was talking about. It has nothing to do with the fact of being fluent in a foreign language, but with a technical misuse of a term that I should have corrected if I had taken the time to read back what I wrote. My fault, I admit it, but there was no need for a language crucifixion, nor unfounded allegations. Ite missa est.

You're using terms that nobody today generally uses. Tension is a vintage word for Voltage. Just saying.

Please don't be so touchy when someone is trying to help you. 

[Hellzero]

You know what I love about BassChat : the members ! After a tsunami, there's never a second one.

[slojo]

Have you seen these kits, I think they look very cool?

I could be very tempted to build one.

https://www.trinityamps.com/product/trinity-trip-top-kit/