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Bogen DB230A recap questions from a hobbyist

M

Mechanism

New Member
I'm doing a recap of a Bogen DB230A. I picked up a "cap kit" from a seller on Ebay. The kit he sells is for the DB230, I asked and he said the A was the same, It's not. The power tube's are different, and so fare I've seen mabey 6 circuit differences. The seller advertises he will give tech support to a reasonable point but all I've received are either one line or one word responses with days in-between. No biggie, it just cost me $150 to lean not to go there again. I am a hobbyist who knows enough to be dangerous but I definitely know my way around a soldering iron. The parts sent for the power section were good and restuffing the cans went great. A question I have holding me up is on capacitor styles. Most of the audio caps are axial non-polarized style, and handful are drops. Most of the drops are obvious on where they go because of the value. I have 4 drop caps that are the same rating but lower voltage then the axiels.
How do I know where these same rated but lower voltage drops go in the circuit? I added the schematic im working by. 1000008649.jpg1000008650.jpg Any advice appreciated!
 

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Mechanism said:
I'm doing a recap of a Bogen DB230A. I picked up a "cap kit" from a seller on Ebay. The kit he sells is for the DB230, I asked and he said the A was the same, It's not. The power tube's are different, and so fare I've seen mabey 6 circuit differences. The seller advertises he will give tech support to a reasonable point but all I've received are either one line or one word responses with days in-between. No biggie, it just cost me $150 to lean not to go there again. I am a hobbyist who knows enough to be dangerous but I definitely know my way around a soldering iron. The parts sent for the power section were good and restuffing the cans went great. A question I have holding me up is on capacitor styles. Most of the audio caps are axial non-polarized style, and handful are drops. Most of the drops are obvious on where they go because of the value. I have 4 drop caps that are the same rating but lower voltage then the axiels.
How do I know where these same rated but lower voltage drops go in the circuit? I added the schematic im working by. View attachment 3666085View attachment 3666086 Any advice appreciated!
Click to expand...

The easiest way to do this, is to look at the ratings of the capacitors which you are replacing, and make sure the voltage rating on each replacement is the same or higher. The 630V parts are probably replacing old 600V parts, the 400V parts replacing old 400V parts, and the 250V parts are probably replacing old 200V parts.

When I do a recap I always just order everything 630V (except the very rare 1kV parts) to make my life easier, and i suggest you do the same in the future.

We could analyze the schematic to find out what goes where, but it's much easier to just use the existing parts as a reference.
 
The simplest answer is the best answer here, that is exactly what I did. (I struggle with over thinking simple tasks sometimes and it's more prevalent while teaching myself amp repair) I sat down at the bench after I wrote the question above with the unit open pouring over the schematic and staring at the cap kit contents. Next thing I knew 12 caps were replaced and incorrect parts in the kit were confirmed. I sent the seller a message with the parts list and hope he sends the missing caps. I hope he's receptive to my observations about his kit and makes a new kit specifically for the DB230A. Now that I got my feet wet I'm going to source the caps my self for the second DB230A I bought today! I still would recommend the guy because he does include alot of literature and general advice perfect for a hobbyist starting out, and I'm sure it must be incredibly difficult to get those kits perfect every time. Thanks for the sound advice, I would love to go pro at this as my whole life I have had a passion for tube circuitry devices, especially hifi.
 
maxhifi said:
The easiest way to do this, is to look at the ratings of the capacitors which you are replacing, and make sure the voltage rating on each replacement is the same or higher. The 630V parts are probably replacing old 600V parts, the 400V parts replacing old 400V parts, and the 250V parts are probably replacing old 200V parts.

When I do a recap I always just order everything 630V (except the very rare 1kV parts) to make my life easier, and i suggest you do the same in the future.

We could analyze the schematic to find out what goes where, but it's much easier to just use the existing parts as a reference.
Click to expand...
Any sonic differences in the drop to axiels caps, or does that answer dwell firmly in the subjective realm?
 
Mechanism said:
Any sonic differences in the drop to axiels caps, or does that answer dwell firmly in the subjective realm?
Click to expand...
indeed subjective until someone figures out a way to measure the perception of depth and dimension properties of recorded music that easily rules out confirmation bias and placebo effect. humans are strange critters indeed.

www.humblehomemadehifi.com

Humble Homemade Hifi - Cap Test

Humble Homemade Hifi - Very high quality loudspeaker kits, components, upgrades, modifications and custom solutions.
www.humblehomemadehifi.com www.humblehomemadehifi.com
*down the capacitor quality/price rabbit hole, if your curious

*comparison from a single point of view, points to ponder or food for thought

one of these days i will pull the trigger on some jantzen caps for a few tube systems (power amp, integrated amp).
 
sae-7125 said:
indeed subjective until someone figures out a way to measure the perception of depth and dimension properties of recorded music that easily rules out confirmation bias and placebo effect. humans are strange critters indeed.

www.humblehomemadehifi.com

Humble Homemade Hifi - Cap Test

Humble Homemade Hifi - Very high quality loudspeaker kits, components, upgrades, modifications and custom solutions.
www.humblehomemadehifi.com www.humblehomemadehifi.com
*down the capacitor quality/price rabbit hole, if your curious

*comparison from a single point of view, points to ponder or food for thought

one of these days i will pull the trigger on some jantzen caps for a few tube systems (power amp, integrated amp).
Click to expand...
I'm sure they have a guy on it somewhere that's this close to figuring out a way to measure the perception of depth and dimension properties of recorded music that easily rules out confirmation bias and placebo effect. Also I will definitely check out that Humble stuff, I'm firmly in my Jonny 5 need more input stage of researching everything capacitors.
 
I always thought this and its cousins the DB130 and DB230 were interesting amps. Sweep tubes and an active screen regulator are just not things you commonly see in home hifi gear. Never had my hands in one, its just a cool circuit.
 
sae-7125 said:
indeed subjective until someone figures out a way to measure the perception of depth and dimension properties of recorded music that easily rules out confirmation bias and placebo effect. humans are strange critters indeed.

www.humblehomemadehifi.com

Humble Homemade Hifi - Cap Test

Humble Homemade Hifi - Very high quality loudspeaker kits, components, upgrades, modifications and custom solutions.
www.humblehomemadehifi.com www.humblehomemadehifi.com
*down the capacitor quality/price rabbit hole, if your curious

*comparison from a single point of view, points to ponder or food for thought

one of these days i will pull the trigger on some jantzen caps for a few tube systems (power amp, integrated amp).
Click to expand...
I am loving this link, there is so much juicy capacitor information and food for thought. Exactly what I needed to start this learning journey.
 
problem with most of those "capacitor tests" is that its purely a subjective opinion of the person writing the article. I would suggest keeping that in mind before drawing any conclusions about these results or just going with whatever someone on the internet has to say.

Or just decide what caps you want and shop for opinions until you find someone singing it's praises. Its almost certain someone will be a fan.
 
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